params keyword - Page 163

CodePlex Daily Summary for Sunday, May 20, 2012

CodePlex Daily Summary for Sunday, May 20, 2012Popular ReleasesExtAspNet: ExtAspNet v3.1.6: ExtAspNet - ?? ExtJS ??? ASP.NET 2.0 ???，????? AJAX ?????????? ExtAspNet ????? ExtJS ??? ASP.NET 2.0 ???，????? AJAX ??????????。 ExtAspNet ??????? JavaScript，?? CSS，?? UpdatePanel，?? ViewState，?? WebServices ???????。 ??????: IE 7.0, Firefox 3.6, Chrome 3.0, Opera 10.5, Safari 3.0+ ????：Apache License 2.0 (Apache) ??：http://bbs.extasp.net/ ??：http://demo.extasp.net/ ??：http://doc.extasp.net/ ??：http://extaspnet.codeplex.com/ ??：http://sanshi.cnblogs.com/ ????： +2012-05-20 v3.1.6 -??RowD...totalem: version 2012.05.20.1: Beta version added function to create new empty file added function to create new file from clipboard content (save content of clipboard to file) added feature to direct view file from FTP server added feature to direct edit file from FTP server added feature to direct encrypt and copy files to FTP server added feature to direct copy and decrypt files from FTP servergGrid - Editable jQuery Grid: Initial Version release: The js file is the initial version of gGrid. Below are some of the limitations of the gGrid plugin The grid requires to return a MVC partial view to render the updated grid on screen.WatchersNET CKEditor™ Provider for DotNetNuke®: CKEditor Provider 1.14.05: Whats New Added New Editor Skin "BootstrapCK-Skin" Added New Editor Skin "Slick" Added Dnn Pages Drop Down to the Link Dialog (to quickly link to a portal tab) changes Fixed Issue #6956 Localization issue with some languages Fixed Issue #6930 Folder Tree view was not working in some cases Changed the user folder from User name to User id User Folder is now used when using Upload Function and User Folder is enabled File-Browser Fixed Resizer Preview Image Optimized the oEmbed Pl...PHPExcel: PHPExcel 1.7.7: See Change Log for details of the new features and bugfixes included in this release. BREAKING CHANGE! From PHPExcel 1.7.8 onwards, the 3rd-party tcPDF library will no longer be bundled with PHPExcel for rendering PDF files through the PDF Writer. The PDF Writer is being rewritten to allow a choice of 3rd party PDF libraries (tcPDF, mPDF, and domPDF initially), none of which will be bundled with PHPExcel, but which can be downloaded seperately from the appropriate sites.GhostBuster: GhostBuster Setup (91520): Added WMI based RestorePoint support Removed test code from program.cs Improved counting. Changed color of ghosted but unfiltered devices. Changed HwEntries into an ObservableCollection. Added Properties Form. Added Properties MenuItem to Context Menu. Added Hide Unfiltered Devices to Context Menu. If you like this tool, leave me a note, rate this project or write a review or Donate to Ghostbuster. Donate to GhostbusterC#??????EXCEL??、??、????????：DataPie（??MSSQL 2008、ORACLE、ACCESS 2007）: DataPie_V3.2: V3.2, 2012?5?19? ????ORACLE??????。AvalonDock: AvalonDock 2.0.0795: Welcome to the Beta release of AvalonDock 2.0 After 4 months of hard work I'm ready to upload the beta version of AvalonDock 2.0. This new version boosts a lot of new features and now is stable enough to be deployed in production scenarios. For this reason I encourage everyone is using AD 1.3 or earlier to upgrade soon to this new version. The final version is scheduled for the end of June. What is included in Beta: 1) Stability! thanks to all users contribution I’ve corrected a lot of issues...myCollections: Version 2.1.0.0: New in this version : Improved UI New Metro Skin Improved Performance Added Proxy Settings New Music and Books Artist detail Lot of Bug FixingAspxCommerce: AspxCommerce1.1: AspxCommerce - 'Flexible and easy eCommerce platform' offers a complete e-Commerce solution that allows you to build and run your fully functional online store in minutes. You can create your storefront; manage the products through categories and subcategories, accept payments through credit cards and ship the ordered products to the customers. We have everything set up for you, so that you can only focus on building your own online store. Note: To login as a superuser, the username and pass...SiteMap Editor for Microsoft Dynamics CRM 2011: SiteMap Editor (1.1.1616.403): BUG FIX Hide save button when Titles or Descriptions element is selectedMapWindow 6 Desktop GIS: MapWindow 6.1.2: Looking for a .Net GIS Map Application?MapWindow 6 Desktop GIS is an open source desktop GIS for Microsoft Windows that is built upon the DotSpatial Library. This release requires .Net 4 (Client Profile). Are you a software developer?Instead of downloading MapWindow for development purposes, get started with with the DotSpatial template. The extensions you create from the template can be loaded in MapWindow.DotSpatial: DotSpatial 1.2: This is a Minor Release. See the changes in the issue tracker. Minimal -- includes DotSpatial core and essential extensions Extended -- includes debugging symbols and additional extensions Tutorials are available. Just want to run the software? End user (non-programmer) version available branded as MapWindow Want to add your own feature? Develop a plugin, using the template and contribute to the extension feed (you can also write extensions that you distribute in other ways). Components ...Mugen Injection: Mugen Injection 2.2.1 (WinRT supported): Added ManagedScopeLifecycle. Increase performance. Added support for resolve 'params'.Microsoft Ajax Minifier: Microsoft Ajax Minifier 4.52: Make preprocessor comment-statements nestable; add the ///#IFNDEF statement. (Discussion #355785) Don't throw an error for old-school JScript event handlers, and don't rename them if they aren't global functions.DotNetNuke® Events: 06.00.00: This is a serious release of Events. DNN 6 form pattern - We have take the full route towards DNN6: most notably the incorporation of the DNN6 form pattern with streamlined UX/UI. We have also tried to change all formatting to a div based structure. A daunting task, since the Events module contains a lot of forms. Roger has done a splendid job by going through all the forms in great detail, replacing all table style layouts into the new DNN6 div class="dnnForm XXX" type of layout with chang...LogicCircuit: LogicCircuit 2.12.5.15: Logic Circuit - is educational software for designing and simulating logic circuits. Intuitive graphical user interface, allows you to create unrestricted circuit hierarchy with multi bit buses, debug circuits behavior with oscilloscope, and navigate running circuits hierarchy. Changes of this versionThis release is fixing one but nasty bug. Two functions XOR and XNOR when used with 3 or more inputs were incorrectly evaluating their results. If you have a circuit that is using these functions...LINQ to Twitter: LINQ to Twitter Beta v2.0.25: Supports .NET 3.5, .NET 4.0, Silverlight 4.0, Windows Phone 7.1, Client Profile, and Windows 8. 100% Twitter API coverage. Also available via NuGet! Follow @JoeMayo.BlogEngine.NET: BlogEngine.NET 2.6: Get DotNetBlogEngine for 3 Months Free! Click Here for More Info BlogEngine.NET Hosting - 3 months free! Cheap ASP.NET Hosting - $4.95/Month - Click Here!! Click Here for More Info Cheap ASP.NET Hosting - $4.95/Month - Click Here! If you want to set up and start using BlogEngine.NET right away, you should download the Web project. If you want to extend or modify BlogEngine.NET, you should download the source code. If you are upgrading from a previous version of BlogEngine.NET, please take...BlackJumboDog: Ver5.6.2: 2012.05.07 Ver5.6.2 (1)　Web???????、????????·????????? (2)　Web???????、?????????? COMSPEC PATHEXT WINDIR SERVERADDR SERVERPORT DOCUMENTROOT SERVERADMIN REMOTE_PORT HTTPACCEPTCHRSET HTTPACCEPTLANGUAGE HTTPACCEPTEXCODINGNew ProjectsAkumu Island: Akumu Island is a game being developed by Jared Thomson. At this time, things are still fairly under wraps. The source code is still available though.BasicSocialNetworkingSite: Basic/Simple Social Networking Web Site using C# - ASP.NETCasse Brique: Projet Casse-brique.Cdts.iOS: Cdts iOSCluster2: To be Published...CrowdMOS: CrowdMOS is a set of scripts and tools for performing evaluations of the subjective quality of media such as audio or images using crowdsourcing via Amazon Mechanical Turk. This project is designed to enable low cost, efficient assessments of signal processing algorithms, e.g., compression, denoising, or enhancement, using standard tests such as MOS (Mean Opinion Score) or MUSHRA.Data Frame Loader: A simple C# API for loading tabular dataframes into Microsoft SQL Server database using only a small number of tables to represent any kind of dataframe.Dynamic Segmentation Utility SOE Rest: Dynamic Segmentation Utility SOE Rest for ArcGIS Server 10 (msd)field2012: This is private projectFix soft HyperAero Form: Fix soft Aero Form (HyperAero Edition) works on both xp and Win7 and supports Customizable Animation Effects (On showing and closing form),Gradient Support (Multicolor Gradient Background,Gradient Editor Control),Power Functions (Shutdown,etc with Timer support) ,Aero Glass Support (Extend Margins,Aero Blur,Aero Glow text,Basic Theme Support),Aero Properties (IsWindowsAeroEnabled,AeroColor and opacity),Aero Events,Unlock Hidden Properties (EnableCloseButton, CaptionRenderMode, ActivateOn...Gamer: A program intended to be a PC gamers' companion app by providing features such as: * Customizable system tray menu that lists (favourite/frequent/all) games (as shown in the Windows Games Explorer) for quick launching (and clean desktops). * Ability to edit listings in the Windows Game Explorer * Once these goals are met other handy features can be implemented to increase the value of this app. This program should compliment existing programs used by gamers rather than compete w...gGrid - Editable jQuery Grid: This a jQuery plugin. The plugin will add three buttons Add/Edit/Delete which will need a popup control to add/edit data. Developer using this plugin need to define an HTML table and an HTML DIV which will be used for popup. Also MVC action method to handle the CRUD operation. The plug requires an MVC partial view to be returned from the add edit delete methods to update the table data.HoiChoMuaBan: h?i ch? mua bánmyfirstgit: ???????Nova Code: Nova code is a language to implement processor instructions, states, and other features planned soon for the NEmulation framework. Right now this project will be worked on separately, then integrated into NEmulation.Pocket Book App: Just try it!State Machine .netmf: StateMachineExample for .netmf C# uVersionClientCache: uVersionClientCache is a custom macro to always automatically version (URL querstring parameter) your files based on a MD5 hash of the file contents or file last modified date to prevent issues with client browsers caching an old file after you have changed it.XNA Shader Composer: XNA Shader Composer is a solution for Visual Studio 2010 and XNA 4.0. The goal is to create an environment for learn and create differents HLSL programs.???Disable????: ??????????????errdisable??，????????。

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12c - flashforward, flashback or see it as of now...

- by noreply(at)blogger.com (Thomas Kyte)

Oracle 9i exposed flashback query to developers for the first time. The ability to flashback query dates back to version 4 however (it just wasn't exposed). Every time you run a query in Oracle it is in fact a flashback query - it is what multi-versioning is all about.However, there was never a flashforward query (well, ok, the workspace manager has this capability - but with lots of extra baggage). We've never been able to ask a table "what will you look like tomorrow" - but now we do.The capability is called Temporal Validity. If you have a table with data that is effective dated - has a "start date" and "end date" column in it - we can now query it using flashback query like syntax. The twist is - the date we "flashback" to can be in the future. It works by rewriting the query to transparently the necessary where clause and filter out the right rows for the right period of time - and since you can have records whose start date is in the future - you can query a table and see what it would look like at some future time.Here is a quick example, we'll start with a table:ops$tkyte%ORA12CR1> create table addresses 2 ( empno number, 3 addr_data varchar2(30), 4 start_date date, 5 end_date date, 6 period for valid(start_date,end_date) 7 ) 8 /Table created.the new bit is on line 6 (it can be altered into an existing table - so any table you have with a start/end date column will be a candidate). The keyword is PERIOD, valid is an identifier I chose - it could have been foobar, valid just sounds nice in the query later. You identify the columns in your table - or we can create them for you if they don't exist. Then you just create some data:ops$tkyte%ORA12CR1> insert into addresses (empno, addr_data, start_date, end_date ) 2 values ( 1234, '123 Main Street', trunc(sysdate-5), trunc(sysdate-2) );1 row created.ops$tkyte%ORA12CR1>ops$tkyte%ORA12CR1> insert into addresses (empno, addr_data, start_date, end_date ) 2 values ( 1234, '456 Fleet Street', trunc(sysdate-1), trunc(sysdate+1) );1 row created.ops$tkyte%ORA12CR1>ops$tkyte%ORA12CR1> insert into addresses (empno, addr_data, start_date, end_date ) 2 values ( 1234, '789 1st Ave', trunc(sysdate+2), null );1 row created.and you can either see all of the data:ops$tkyte%ORA12CR1> select * from addresses; EMPNO ADDR_DATA START_DAT END_DATE---------- ------------------------------ --------- --------- 1234 123 Main Street 27-JUN-13 30-JUN-13 1234 456 Fleet Street 01-JUL-13 03-JUL-13 1234 789 1st Ave 04-JUL-13or query "as of" some point in time - as you can see in the predicate section - it is just doing a query rewrite to automate the "where" filters:ops$tkyte%ORA12CR1> select * from addresses as of period for valid sysdate-3; EMPNO ADDR_DATA START_DAT END_DATE---------- ------------------------------ --------- --------- 1234 123 Main Street 27-JUN-13 30-JUN-13ops$tkyte%ORA12CR1> @planops$tkyte%ORA12CR1> select * from table(dbms_xplan.display_cursor);PLAN_TABLE_OUTPUT-------------------------------------------------------------------------------SQL_ID cthtvvm0dxvva, child number 0-------------------------------------select * from addresses as of period for valid sysdate-3Plan hash value: 3184888728-------------------------------------------------------------------------------| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |-------------------------------------------------------------------------------| 0 | SELECT STATEMENT | | | | 3 (100)| ||* 1 | TABLE ACCESS FULL| ADDRESSES | 1 | 48 | 3 (0)| 00:00:01 |-------------------------------------------------------------------------------Predicate Information (identified by operation id):--------------------------------------------------- 1 - filter((("T"."START_DATE" IS NULL OR "T"."START_DATE"<=SYSDATE@!-3) AND ("T"."END_DATE" IS NULL OR "T"."END_DATE">SYSDATE@!-3)))Note----- - dynamic statistics used: dynamic sampling (level=2)24 rows selected.ops$tkyte%ORA12CR1> select * from addresses as of period for valid sysdate; EMPNO ADDR_DATA START_DAT END_DATE---------- ------------------------------ --------- --------- 1234 456 Fleet Street 01-JUL-13 03-JUL-13ops$tkyte%ORA12CR1> @planops$tkyte%ORA12CR1> select * from table(dbms_xplan.display_cursor);PLAN_TABLE_OUTPUT-------------------------------------------------------------------------------SQL_ID 26ubyhw9hgk7z, child number 0-------------------------------------select * from addresses as of period for valid sysdatePlan hash value: 3184888728-------------------------------------------------------------------------------| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |-------------------------------------------------------------------------------| 0 | SELECT STATEMENT | | | | 3 (100)| ||* 1 | TABLE ACCESS FULL| ADDRESSES | 1 | 48 | 3 (0)| 00:00:01 |-------------------------------------------------------------------------------Predicate Information (identified by operation id):--------------------------------------------------- 1 - filter((("T"."START_DATE" IS NULL OR "T"."START_DATE"<=SYSDATE@!) AND ("T"."END_DATE" IS NULL OR "T"."END_DATE">SYSDATE@!)))Note----- - dynamic statistics used: dynamic sampling (level=2)24 rows selected.ops$tkyte%ORA12CR1> select * from addresses as of period for valid sysdate+3; EMPNO ADDR_DATA START_DAT END_DATE---------- ------------------------------ --------- --------- 1234 789 1st Ave 04-JUL-13ops$tkyte%ORA12CR1> @planops$tkyte%ORA12CR1> select * from table(dbms_xplan.display_cursor);PLAN_TABLE_OUTPUT-------------------------------------------------------------------------------SQL_ID 36bq7shnhc888, child number 0-------------------------------------select * from addresses as of period for valid sysdate+3Plan hash value: 3184888728-------------------------------------------------------------------------------| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |-------------------------------------------------------------------------------| 0 | SELECT STATEMENT | | | | 3 (100)| ||* 1 | TABLE ACCESS FULL| ADDRESSES | 1 | 48 | 3 (0)| 00:00:01 |-------------------------------------------------------------------------------Predicate Information (identified by operation id):--------------------------------------------------- 1 - filter((("T"."START_DATE" IS NULL OR "T"."START_DATE"<=SYSDATE@!+3) AND ("T"."END_DATE" IS NULL OR "T"."END_DATE">SYSDATE@!+3)))Note----- - dynamic statistics used: dynamic sampling (level=2)24 rows selected.All in all a nice, easy way to query effective dated information as of a point in time without a complex where clause. You need to maintain the data - it isn't that a delete will turn into an update the end dates a record or anything - but if you have tables with start/end dates, this will make it much easier to query them.

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Announcing release of ASP.NET MVC 3, IIS Express, SQL CE 4, Web Farm Framework, Orchard, WebMatrix

- by ScottGu

I’m excited to announce the release today of several products: ASP.NET MVC 3 NuGet IIS Express 7.5 SQL Server Compact Edition 4 Web Deploy and Web Farm Framework 2.0 Orchard 1.0 WebMatrix 1.0 The above products are all free. They build upon the .NET 4 and VS 2010 release, and add a ton of additional value to ASP.NET (both Web Forms and MVC) and the Microsoft Web Server stack. ASP.NET MVC 3 Today we are shipping the final release of ASP.NET MVC 3. You can download and install ASP.NET MVC 3 here. The ASP.NET MVC 3 source code (released under an OSI-compliant open source license) can also optionally be downloaded here. ASP.NET MVC 3 is a significant update that brings with it a bunch of great features. Some of the improvements include: Razor ASP.NET MVC 3 ships with a new view-engine option called “Razor” (in addition to continuing to support/enhance the existing .aspx view engine). Razor minimizes the number of characters and keystrokes required when writing a view template, and enables a fast, fluid coding workflow. Unlike most template syntaxes, with Razor you do not need to interrupt your coding to explicitly denote the start and end of server blocks within your HTML. The Razor parser is smart enough to infer this from your code. This enables a compact and expressive syntax which is clean, fast and fun to type. You can learn more about Razor from some of the blog posts I’ve done about it over the last 6 months Introducing Razor New @model keyword in Razor Layouts with Razor Server-Side Comments with Razor Razor’s @: and <text> syntax Implicit and Explicit code nuggets with Razor Layouts and Sections with Razor Today’s release supports full code intellisense support for Razor (both VB and C#) with Visual Studio 2010 and the free Visual Web Developer 2010 Express. JavaScript Improvements ASP.NET MVC 3 enables richer JavaScript scenarios and takes advantage of emerging HTML5 capabilities. The AJAX and Validation helpers in ASP.NET MVC 3 now use an Unobtrusive JavaScript based approach. Unobtrusive JavaScript avoids injecting inline JavaScript into HTML, and enables cleaner separation of behavior using the new HTML 5 “data-“ attribute convention (which conveniently works on older browsers as well – including IE6). This keeps your HTML tight and clean, and makes it easier to optionally swap out or customize JS libraries. ASP.NET MVC 3 now includes built-in support for posting JSON-based parameters from client-side JavaScript to action methods on the server. This makes it easier to exchange data across the client and server, and build rich JavaScript front-ends. We think this capability will be particularly useful going forward with scenarios involving client templates and data binding (including the jQuery plugins the ASP.NET team recently contributed to the jQuery project). Previous releases of ASP.NET MVC included the core jQuery library. ASP.NET MVC 3 also now ships the jQuery Validate plugin (which our validation helpers use for client-side validation scenarios). We are also now shipping and including jQuery UI by default as well (which provides a rich set of client-side JavaScript UI widgets for you to use within projects). Improved Validation ASP.NET MVC 3 includes a bunch of validation enhancements that make it even easier to work with data. Client-side validation is now enabled by default with ASP.NET MVC 3 (using an onbtrusive javascript implementation). Today’s release also includes built-in support for Remote Validation - which enables you to annotate a model class with a validation attribute that causes ASP.NET MVC to perform a remote validation call to a server method when validating input on the client. The validation features introduced within .NET 4’s System.ComponentModel.DataAnnotations namespace are now supported by ASP.NET MVC 3. This includes support for the new IValidatableObject interface – which enables you to perform model-level validation, and allows you to provide validation error messages specific to the state of the overall model, or between two properties within the model. ASP.NET MVC 3 also supports the improvements made to the ValidationAttribute class in .NET 4. ValidationAttribute now supports a new IsValid overload that provides more information about the current validation context, such as what object is being validated. This enables richer scenarios where you can validate the current value based on another property of the model. We’ve shipped a built-in [Compare] validation attribute with ASP.NET MVC 3 that uses this support and makes it easy out of the box to compare and validate two property values. You can use any data access API or technology with ASP.NET MVC. This past year, though, we’ve worked closely with the .NET data team to ensure that the new EF Code First library works really well for ASP.NET MVC applications. These two posts of mine cover the latest EF Code First preview and demonstrates how to use it with ASP.NET MVC 3 to enable easy editing of data (with end to end client+server validation support). The final release of EF Code First will ship in the next few weeks. Today we are also publishing the first preview of a new MvcScaffolding project. It enables you to easily scaffold ASP.NET MVC 3 Controllers and Views, and works great with EF Code-First (and is pluggable to support other data providers). You can learn more about it – and install it via NuGet today - from Steve Sanderson’s MvcScaffolding blog post. Output Caching Previous releases of ASP.NET MVC supported output caching content at a URL or action-method level. With ASP.NET MVC V3 we are also enabling support for partial page output caching – which allows you to easily output cache regions or fragments of a response as opposed to the entire thing. This ends up being super useful in a lot of scenarios, and enables you to dramatically reduce the work your application does on the server. The new partial page output caching support in ASP.NET MVC 3 enables you to easily re-use cached sub-regions/fragments of a page across multiple URLs on a site. It supports the ability to cache the content either on the web-server, or optionally cache it within a distributed cache server like Windows Server AppFabric or memcached. I’ll post some tutorials on my blog that show how to take advantage of ASP.NET MVC 3’s new output caching support for partial page scenarios in the future. Better Dependency Injection ASP.NET MVC 3 provides better support for applying Dependency Injection (DI) and integrating with Dependency Injection/IOC containers. With ASP.NET MVC 3 you no longer need to author custom ControllerFactory classes in order to enable DI with Controllers. You can instead just register a Dependency Injection framework with ASP.NET MVC 3 and it will resolve dependencies not only for Controllers, but also for Views, Action Filters, Model Binders, Value Providers, Validation Providers, and Model Metadata Providers that you use within your application. This makes it much easier to cleanly integrate dependency injection within your projects. Other Goodies ASP.NET MVC 3 includes dozens of other nice improvements that help to both reduce the amount of code you write, and make the code you do write cleaner. Here are just a few examples: Improved New Project dialog that makes it easy to start new ASP.NET MVC 3 projects from templates. Improved Add->View Scaffolding support that enables the generation of even cleaner view templates. New ViewBag property that uses .NET 4’s dynamic support to make it easy to pass late-bound data from Controllers to Views. Global Filters support that allows specifying cross-cutting filter attributes (like [HandleError]) across all Controllers within an app. New [AllowHtml] attribute that allows for more granular request validation when binding form posted data to models. Sessionless controller support that allows fine grained control over whether SessionState is enabled on a Controller. New ActionResult types like HttpNotFoundResult and RedirectPermanent for common HTTP scenarios. New Html.Raw() helper to indicate that output should not be HTML encoded. New Crypto helpers for salting and hashing passwords. And much, much more… Learn More about ASP.NET MVC 3 We will be posting lots of tutorials and samples on the http://asp.net/mvc site in the weeks ahead. Below are two good ASP.NET MVC 3 tutorials available on the site today: Build your First ASP.NET MVC 3 Application: VB and C# Building the ASP.NET MVC 3 Music Store We’ll post additional ASP.NET MVC 3 tutorials and videos on the http://asp.net/mvc site in the future. Visit it regularly to find new tutorials as they are published. How to Upgrade Existing Projects ASP.NET MVC 3 is compatible with ASP.NET MVC 2 – which means it should be easy to update existing MVC projects to ASP.NET MVC 3. The new features in ASP.NET MVC 3 build on top of the foundational work we’ve already done with the MVC 1 and MVC 2 releases – which means that the skills, knowledge, libraries, and books you’ve acquired are all directly applicable with the MVC 3 release. MVC 3 adds new features and capabilities – it doesn’t obsolete existing ones. You can upgrade existing ASP.NET MVC 2 projects by following the manual upgrade steps in the release notes. Alternatively, you can use this automated ASP.NET MVC 3 upgrade tool to easily update your existing projects. Localized Builds Today’s ASP.NET MVC 3 release is available in English. We will be releasing localized versions of ASP.NET MVC 3 (in 9 languages) in a few days. I’ll blog pointers to the localized downloads once they are available. NuGet Today we are also shipping NuGet – a free, open source, package manager that makes it easy for you to find, install, and use open source libraries in your projects. It works with all .NET project types (including ASP.NET Web Forms, ASP.NET MVC, WPF, WinForms, Silverlight, and Class Libraries). You can download and install it here. NuGet enables developers who maintain open source projects (for example, .NET projects like Moq, NHibernate, Ninject, StructureMap, NUnit, Windsor, Raven, Elmah, etc) to package up their libraries and register them with an online gallery/catalog that is searchable. The client-side NuGet tools – which include full Visual Studio integration – make it trivial for any .NET developer who wants to use one of these libraries to easily find and install it within the project they are working on. NuGet handles dependency management between libraries (for example: library1 depends on library2). It also makes it easy to update (and optionally remove) libraries from your projects later. It supports updating web.config files (if a package needs configuration settings). It also allows packages to add PowerShell scripts to a project (for example: scaffold commands). Importantly, NuGet is transparent and clean – and does not install anything at the system level. Instead it is focused on making it easy to manage libraries you use with your projects. Our goal with NuGet is to make it as simple as possible to integrate open source libraries within .NET projects. NuGet Gallery This week we also launched a beta version of the http://nuget.org web-site – which allows anyone to easily search and browse an online gallery of open source packages available via NuGet. The site also now allows developers to optionally submit new packages that they wish to share with others. You can learn more about how to create and share a package here. There are hundreds of open-source .NET projects already within the NuGet Gallery today. We hope to have thousands there in the future. IIS Express 7.5 Today we are also shipping IIS Express 7.5. IIS Express is a free version of IIS 7.5 that is optimized for developer scenarios. It works for both ASP.NET Web Forms and ASP.NET MVC project types. We think IIS Express combines the ease of use of the ASP.NET Web Server (aka Cassini) currently built-into Visual Studio today with the full power of IIS. Specifically: It’s lightweight and easy to install (less than 5Mb download and a quick install) It does not require an administrator account to run/debug applications from Visual Studio It enables a full web-server feature set – including SSL, URL Rewrite, and other IIS 7.x modules It supports and enables the same extensibility model and web.config file settings that IIS 7.x support It can be installed side-by-side with the full IIS web server as well as the ASP.NET Development Server (they do not conflict at all) It works on Windows XP and higher operating systems – giving you a full IIS 7.x developer feature-set on all Windows OS platforms IIS Express (like the ASP.NET Development Server) can be quickly launched to run a site from a directory on disk. It does not require any registration/configuration steps. This makes it really easy to launch and run for development scenarios. You can also optionally redistribute IIS Express with your own applications if you want a lightweight web-server. The standard IIS Express EULA now includes redistributable rights. Visual Studio 2010 SP1 adds support for IIS Express. Read my VS 2010 SP1 and IIS Express blog post to learn more about what it enables. SQL Server Compact Edition 4 Today we are also shipping SQL Server Compact Edition 4 (aka SQL CE 4). SQL CE is a free, embedded, database engine that enables easy database storage. No Database Installation Required SQL CE does not require you to run a setup or install a database server in order to use it. You can simply copy the SQL CE binaries into the \bin directory of your ASP.NET application, and then your web application can use it as a database engine. No setup or extra security permissions are required for it to run. You do not need to have an administrator account on the machine. Just copy your web application onto any server and it will work. This is true even of medium-trust applications running in a web hosting environment. SQL CE runs in-memory within your ASP.NET application and will start-up when you first access a SQL CE database, and will automatically shutdown when your application is unloaded. SQL CE databases are stored as files that live within the \App_Data folder of your ASP.NET Applications. Works with Existing Data APIs SQL CE 4 works with existing .NET-based data APIs, and supports a SQL Server compatible query syntax. This means you can use existing data APIs like ADO.NET, as well as use higher-level ORMs like Entity Framework and NHibernate with SQL CE. This enables you to use the same data programming skills and data APIs you know today. Supports Development, Testing and Production Scenarios SQL CE can be used for development scenarios, testing scenarios, and light production usage scenarios. With the SQL CE 4 release we’ve done the engineering work to ensure that SQL CE won’t crash or deadlock when used in a multi-threaded server scenario (like ASP.NET). This is a big change from previous releases of SQL CE – which were designed for client-only scenarios and which explicitly blocked running in web-server environments. Starting with SQL CE 4 you can use it in a web-server as well. There are no license restrictions with SQL CE. It is also totally free. Tooling Support with VS 2010 SP1 Visual Studio 2010 SP1 adds support for SQL CE 4 and ASP.NET Projects. Read my VS 2010 SP1 and SQL CE 4 blog post to learn more about what it enables. Web Deploy and Web Farm Framework 2.0 Today we are also releasing Microsoft Web Deploy V2 and Microsoft Web Farm Framework V2. These services provide a flexible and powerful way to deploy ASP.NET applications onto either a single server, or across a web farm of machines. You can learn more about these capabilities from my previous blog posts on them: Introducing the Microsoft Web Farm Framework Automating Deployment with Microsoft Web Deploy Visit the http://iis.net website to learn more and install them. Both are free. Orchard 1.0 Today we are also releasing Orchard v1.0. Orchard is a free, open source, community based project. It provides Content Management System (CMS) and Blogging System support out of the box, and makes it possible to easily create and manage web-sites without having to write code (site owners can customize a site through the browser-based editing tools built-into Orchard). Read these tutorials to learn more about how you can setup and manage your own Orchard site. Orchard itself is built as an ASP.NET MVC 3 application using Razor view templates (and by default uses SQL CE 4 for data storage). Developers wishing to extend an Orchard site with custom functionality can open and edit it as a Visual Studio project – and add new ASP.NET MVC Controllers/Views to it. WebMatrix 1.0 WebMatrix is a new, free, web development tool from Microsoft that provides a suite of technologies that make it easier to enable website development. It enables a developer to start a new site by browsing and downloading an app template from an online gallery of web applications (which includes popular apps like Umbraco, DotNetNuke, Orchard, WordPress, Drupal and Joomla). Alternatively it also enables developers to create and code web sites from scratch. WebMatrix is task focused and helps guide developers as they work on sites. WebMatrix includes IIS Express, SQL CE 4, and ASP.NET - providing an integrated web-server, database and programming framework combination. It also includes built-in web publishing support which makes it easy to find and deploy sites to web hosting providers. You can learn more about WebMatrix from my Introducing WebMatrix blog post this summer. Visit http://microsoft.com/web to download and install it today. Summary I’m really excited about today’s releases – they provide a bunch of additional value that makes web development with ASP.NET, Visual Studio and the Microsoft Web Server a lot better. A lot of folks worked hard to share this with you today. On behalf of my whole team – we hope you enjoy them! Scott P.S. In addition to blogging, I am also now using Twitter for quick updates and to share links. Follow me at: twitter.com/scottgu

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Creating STA COM compatible ASP.NET Applications

- by Rick Strahl

When building ASP.NET applications that interface with old school COM objects like those created with VB6 or Visual FoxPro (MTDLL), it's extremely important that the threads that are serving requests use Single Threaded Apartment Threading. STA is a COM built-in technology that allows essentially single threaded components to operate reliably in a multi-threaded environment. STA's guarantee that COM objects instantiated on a specific thread stay on that specific thread and any access to a COM object from another thread automatically marshals that thread to the STA thread. The end effect is that you can have multiple threads, but a COM object instance lives on a fixed never changing thread. ASP.NET by default uses MTA (multi-threaded apartment) threads which are truly free spinning threads that pay no heed to COM object marshaling. This is vastly more efficient than STA threading which has a bit of overhead in determining whether it's OK to run code on a given thread or whether some sort of thread/COM marshaling needs to occur. MTA COM components can be very efficient, but STA COM components in a multi-threaded environment always tend to have a fair amount of overhead. It's amazing how much COM Interop I still see today so while it seems really old school to be talking about this topic, it's actually quite apropos for me as I have many customers using legacy COM systems that need to interface with other .NET applications. In this post I'm consolidating some of the hacks I've used to integrate with various ASP.NET technologies when using STA COM Components. STA in ASP.NET Support for STA threading in the ASP.NET framework is fairly limited. Specifically only the original ASP.NET WebForms technology supports STA threading directly via its STA Page Handler implementation or what you might know as ASPCOMPAT mode. For WebForms running STA components is as easy as specifying the ASPCOMPAT attribute in the @Page tag:<%@ Page Language="C#" AspCompat="true" %> which runs the page in STA mode. Removing it runs in MTA mode. Simple. Unfortunately all other ASP.NET technologies built on top of the core ASP.NET engine do not support STA natively. So if you want to use STA COM components in MVC or with class ASMX Web Services, there's no automatic way like the ASPCOMPAT keyword available. So what happens when you run an STA COM component in an MTA application? In low volume environments - nothing much will happen. The COM objects will appear to work just fine as there are no simultaneous thread interactions and the COM component will happily run on a single thread or multiple single threads one at a time. So for testing running components in MTA environments may appear to work just fine. However as load increases and threads get re-used by ASP.NET COM objects will end up getting created on multiple different threads. This can result in crashes or hangs, or data corruption in the STA components which store their state in thread local storage on the STA thread. If threads overlap this global store can easily get corrupted which in turn causes problems. STA ensures that any COM object instance loaded always stays on the same thread it was instantiated on. What about COM+? COM+ is supposed to address the problem of STA in MTA applications by providing an abstraction with it's own thread pool manager for COM objects. It steps in to the COM instantiation pipeline and hands out COM instances from its own internally maintained STA Thread pool. This guarantees that the COM instantiation threads are STA threads if using STA components. COM+ works, but in my experience the technology is very, very slow for STA components. It adds a ton of overhead and reduces COM performance noticably in load tests in IIS. COM+ can make sense in some situations but for Web apps with STA components it falls short. In addition there's also the need to ensure that COM+ is set up and configured on the target machine and the fact that components have to be registered in COM+. COM+ also keeps components up at all times, so if a component needs to be replaced the COM+ package needs to be unloaded (same is true for IIS hosted components but it's more common to manage that). COM+ is an option for well established components, but native STA support tends to provide better performance and more consistent usability, IMHO. STA for non supporting ASP.NET Technologies As mentioned above only WebForms supports STA natively. However, by utilizing the WebForms ASP.NET Page handler internally it's actually possible to trick various other ASP.NET technologies and let them work with STA components. This is ugly but I've used each of these in various applications and I've had minimal problems making them work with FoxPro STA COM components which is about as dififcult as it gets for COM Interop in .NET. In this post I summarize several STA workarounds that enable you to use STA threading with these ASP.NET Technologies: ASMX Web Services ASP.NET MVC WCF Web Services ASP.NET Web API ASMX Web Services I start with classic ASP.NET ASMX Web Services because it's the easiest mechanism that allows for STA modification. It also clearly demonstrates how the WebForms STA Page Handler is the key technology to enable the various other solutions to create STA components. Essentially the way this works is to override the WebForms Page class and hijack it's init functionality for processing requests. Here's what this looks like for Web Services:namespace FoxProAspNet { public class WebServiceStaHandler : System.Web.UI.Page, IHttpAsyncHandler { protected override void OnInit(EventArgs e) { IHttpHandler handler = new WebServiceHandlerFactory().GetHandler( this.Context, this.Context.Request.HttpMethod, this.Context.Request.FilePath, this.Context.Request.PhysicalPath); handler.ProcessRequest(this.Context); this.Context.ApplicationInstance.CompleteRequest(); } public IAsyncResult BeginProcessRequest( HttpContext context, AsyncCallback cb, object extraData) { return this.AspCompatBeginProcessRequest(context, cb, extraData); } public void EndProcessRequest(IAsyncResult result) { this.AspCompatEndProcessRequest(result); } } public class AspCompatWebServiceStaHandlerWithSessionState : WebServiceStaHandler, IRequiresSessionState { } } This class overrides the ASP.NET WebForms Page class which has a little known AspCompatBeginProcessRequest() and AspCompatEndProcessRequest() method that is responsible for providing the WebForms ASPCOMPAT functionality. These methods handle routing requests to STA threads. Note there are two classes - one that includes session state and one that does not. If you plan on using ASP.NET Session state use the latter class, otherwise stick to the former. This maps to the EnableSessionState page setting in WebForms. This class simply hooks into this functionality by overriding the BeginProcessRequest and EndProcessRequest methods and always forcing it into the AspCompat methods. The way this works is that BeginProcessRequest() fires first to set up the threads and starts intializing the handler. As part of that process the OnInit() method is fired which is now already running on an STA thread. The code then creates an instance of the actual WebService handler factory and calls its ProcessRequest method to start executing which generates the Web Service result. Immediately after ProcessRequest the request is stopped with Application.CompletRequest() which ensures that the rest of the Page handler logic doesn't fire. This means that even though the fairly heavy Page class is overridden here, it doesn't end up executing any of its internal processing which makes this code fairly efficient. In a nutshell, we're highjacking the Page HttpHandler and forcing it to process the WebService process handler in the context of the AspCompat handler behavior. Hooking up the Handler Because the above is an HttpHandler implementation you need to hook up the custom handler and replace the standard ASMX handler. To do this you need to modify the web.config file (here for IIS 7 and IIS Express): <configuration> <system.webServer> <handlers> <remove name="WebServiceHandlerFactory-Integrated-4.0" /> <add name="Asmx STA Web Service Handler" path="*.asmx" verb="*" type="FoxProAspNet.WebServiceStaHandler" precondition="integrated"/> </handlers> </system.webServer> </configuration> (Note: The name for the WebServiceHandlerFactory-Integrated-4.0 might be slightly different depending on your server version. Check the IIS Handler configuration in the IIS Management Console for the exact name or simply remove the handler from the list there which will propagate to your web.config). For IIS 5 & 6 (Windows XP/2003) or the Visual Studio Web Server use:<configuration> <system.web> <httpHandlers> <remove path="*.asmx" verb="*" /> <add path="*.asmx" verb="*" type="FoxProAspNet.WebServiceStaHandler" /> </httpHandlers> </system.web></configuration> To test, create a new ASMX Web Service and create a method like this: [WebService(Namespace = "http://foxaspnet.org/")] [WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)] public class FoxWebService : System.Web.Services.WebService { [WebMethod] public string HelloWorld() { return "Hello World. Threading mode is: " + System.Threading.Thread.CurrentThread.GetApartmentState(); } } Run this before you put in the web.config configuration changes and you should get: Hello World. Threading mode is: MTA Then put the handler mapping into Web.config and you should see: Hello World. Threading mode is: STA And you're on your way to using STA COM components. It's a hack but it works well! I've used this with several high volume Web Service installations with various customers and it's been fast and reliable. ASP.NET MVC ASP.NET MVC has quickly become the most popular ASP.NET technology, replacing WebForms for creating HTML output. MVC is more complex to get started with, but once you understand the basic structure of how requests flow through the MVC pipeline it's easy to use and amazingly flexible in manipulating HTML requests. In addition, MVC has great support for non-HTML output sources like JSON and XML, making it an excellent choice for AJAX requests without any additional tools. Unlike WebForms ASP.NET MVC doesn't support STA threads natively and so some trickery is needed to make it work with STA threads as well. MVC gets its handler implementation through custom route handlers using ASP.NET's built in routing semantics. To work in an STA handler requires working in the Page Handler as part of the Route Handler implementation. As with the Web Service handler the first step is to create a custom HttpHandler that can instantiate an MVC request pipeline properly:public class MvcStaThreadHttpAsyncHandler : Page, IHttpAsyncHandler, IRequiresSessionState { private RequestContext _requestContext; public MvcStaThreadHttpAsyncHandler(RequestContext requestContext) { if (requestContext == null) throw new ArgumentNullException("requestContext"); _requestContext = requestContext; } public IAsyncResult BeginProcessRequest(HttpContext context, AsyncCallback cb, object extraData) { return this.AspCompatBeginProcessRequest(context, cb, extraData); } protected override void OnInit(EventArgs e) { var controllerName = _requestContext.RouteData.GetRequiredString("controller"); var controllerFactory = ControllerBuilder.Current.GetControllerFactory(); var controller = controllerFactory.CreateController(_requestContext, controllerName); if (controller == null) throw new InvalidOperationException("Could not find controller: " + controllerName); try { controller.Execute(_requestContext); } finally { controllerFactory.ReleaseController(controller); } this.Context.ApplicationInstance.CompleteRequest(); } public void EndProcessRequest(IAsyncResult result) { this.AspCompatEndProcessRequest(result); } public override void ProcessRequest(HttpContext httpContext) { throw new NotSupportedException("STAThreadRouteHandler does not support ProcessRequest called (only BeginProcessRequest)"); } } This handler code figures out which controller to load and then executes the controller. MVC internally provides the information needed to route to the appropriate method and pass the right parameters. Like the Web Service handler the logic occurs in the OnInit() and performs all the processing in that part of the request. Next, we need a RouteHandler that can actually pick up this handler. Unlike the Web Service handler where we simply registered the handler, MVC requires a RouteHandler to pick up the handler. RouteHandlers look at the URL's path and based on that decide on what handler to invoke. The route handler is pretty simple - all it does is load our custom handler: public class MvcStaThreadRouteHandler : IRouteHandler { public IHttpHandler GetHttpHandler(RequestContext requestContext) { if (requestContext == null) throw new ArgumentNullException("requestContext"); return new MvcStaThreadHttpAsyncHandler(requestContext); } } At this point you can instantiate this route handler and force STA requests to MVC by specifying a route. The following sets up the ASP.NET Default Route:Route mvcRoute = new Route("{controller}/{action}/{id}", new RouteValueDictionary( new { controller = "Home", action = "Index", id = UrlParameter.Optional }), new MvcStaThreadRouteHandler()); RouteTable.Routes.Add(mvcRoute); To make this code a little easier to work with and mimic the behavior of the routes.MapRoute() functionality extension method that MVC provides, here is an extension method for MapMvcStaRoute(): public static class RouteCollectionExtensions { public static void MapMvcStaRoute(this RouteCollection routeTable, string name, string url, object defaults = null) { Route mvcRoute = new Route(url, new RouteValueDictionary(defaults), new MvcStaThreadRouteHandler()); RouteTable.Routes.Add(mvcRoute); } } With this the syntax to add route becomes a little easier and matches the MapRoute() method:RouteTable.Routes.MapMvcStaRoute( name: "Default", url: "{controller}/{action}/{id}", defaults: new { controller = "Home", action = "Index", id = UrlParameter.Optional } ); The nice thing about this route handler, STA Handler and extension method is that it's fully self contained. You can put all three into a single class file and stick it into your Web app, and then simply call MapMvcStaRoute() and it just works. Easy! To see whether this works create an MVC controller like this: public class ThreadTestController : Controller { public string ThreadingMode() { return Thread.CurrentThread.GetApartmentState().ToString(); } } Try this test both with only the MapRoute() hookup in the RouteConfiguration in which case you should get MTA as the value. Then change the MapRoute() call to MapMvcStaRoute() leaving all the parameters the same and re-run the request. You now should see STA as the result. You're on your way using STA COM components reliably in ASP.NET MVC. WCF Web Services running through IIS WCF Web Services provide a more robust and wider range of services for Web Services. You can use WCF over HTTP, TCP, and Pipes, and WCF services support WS* secure services. There are many features in WCF that go way beyond what ASMX can do. But it's also a bit more complex than ASMX. As a basic rule if you need to serve straight SOAP Services over HTTP I 'd recommend sticking with the simpler ASMX services especially if COM is involved. If you need WS* support or want to serve data over non-HTTP protocols then WCF makes more sense. WCF is not my forte but I found a solution from Scott Seely on his blog that describes the progress and that seems to work well. I'm copying his code below so this STA information is all in one place and quickly explain. Scott's code basically works by creating a custom OperationBehavior which can be specified via an [STAOperation] attribute on every method. Using his attribute you end up with a class (or Interface if you separate the contract and class) that looks like this: [ServiceContract] public class WcfService { [OperationContract] public string HelloWorldMta() { return Thread.CurrentThread.GetApartmentState().ToString(); } // Make sure you use this custom STAOperationBehavior // attribute to force STA operation of service methods [STAOperationBehavior] [OperationContract] public string HelloWorldSta() { return Thread.CurrentThread.GetApartmentState().ToString(); } } Pretty straight forward. The latter method returns STA while the former returns MTA. To make STA work every method needs to be marked up. The implementation consists of the attribute and OperationInvoker implementation. Here are the two classes required to make this work from Scott's post:public class STAOperationBehaviorAttribute : Attribute, IOperationBehavior { public void AddBindingParameters(OperationDescription operationDescription, System.ServiceModel.Channels.BindingParameterCollection bindingParameters) { } public void ApplyClientBehavior(OperationDescription operationDescription, System.ServiceModel.Dispatcher.ClientOperation clientOperation) { // If this is applied on the client, well, it just doesn’t make sense. // Don’t throw in case this attribute was applied on the contract // instead of the implementation. } public void ApplyDispatchBehavior(OperationDescription operationDescription, System.ServiceModel.Dispatcher.DispatchOperation dispatchOperation) { // Change the IOperationInvoker for this operation. dispatchOperation.Invoker = new STAOperationInvoker(dispatchOperation.Invoker); } public void Validate(OperationDescription operationDescription) { if (operationDescription.SyncMethod == null) { throw new InvalidOperationException("The STAOperationBehaviorAttribute " + "only works for synchronous method invocations."); } } } public class STAOperationInvoker : IOperationInvoker { IOperationInvoker _innerInvoker; public STAOperationInvoker(IOperationInvoker invoker) { _innerInvoker = invoker; } public object[] AllocateInputs() { return _innerInvoker.AllocateInputs(); } public object Invoke(object instance, object[] inputs, out object[] outputs) { // Create a new, STA thread object[] staOutputs = null; object retval = null; Thread thread = new Thread( delegate() { retval = _innerInvoker.Invoke(instance, inputs, out staOutputs); }); thread.SetApartmentState(ApartmentState.STA); thread.Start(); thread.Join(); outputs = staOutputs; return retval; } public IAsyncResult InvokeBegin(object instance, object[] inputs, AsyncCallback callback, object state) { // We don’t handle async… throw new NotImplementedException(); } public object InvokeEnd(object instance, out object[] outputs, IAsyncResult result) { // We don’t handle async… throw new NotImplementedException(); } public bool IsSynchronous { get { return true; } } } The key in this setup is the Invoker and the Invoke method which creates a new thread and then fires the request on this new thread. Because this approach creates a new thread for every request it's not super efficient. There's a bunch of overhead involved in creating the thread and throwing it away after each thread, but it'll work for low volume requests and insure each thread runs in STA mode. If better performance is required it would be useful to create a custom thread manager that can pool a number of STA threads and hand off threads as needed rather than creating new threads on every request. If your Web Service needs are simple and you need only to serve standard SOAP 1.x requests, I would recommend sticking with ASMX services. It's easier to set up and work with and for STA component use it'll be significantly better performing since ASP.NET manages the STA thread pool for you rather than firing new threads for each request. One nice thing about Scotts code is though that it works in any WCF environment including self hosting. It has no dependency on ASP.NET or WebForms for that matter. STA - If you must STA components are a pain in the ass and thankfully there isn't too much stuff out there anymore that requires it. But when you need it and you need to access STA functionality from .NET at least there are a few options available to make it happen. Each of these solutions is a bit hacky, but they work - I've used all of them in production with good results with FoxPro components. I hope compiling all of these in one place here makes it STA consumption a little bit easier. I feel your pain :-) Resources Download STA Handler Code Examples Scott Seely's original STA WCF OperationBehavior Article© Rick Strahl, West Wind Technologies, 2005-2012Posted in FoxPro ASP.NET .NET COM Tweet !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

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An Introduction to Meteor

- by Stephen.Walther

The goal of this blog post is to give you a brief introduction to Meteor which is a framework for building Single Page Apps. In this blog entry, I provide a walkthrough of building a simple Movie database app. What is special about Meteor? Meteor has two jaw-dropping features: Live HTML – If you make any changes to the HTML, CSS, JavaScript, or data on the server then every client shows the changes automatically without a browser refresh. For example, if you change the background color of a page to yellow then every open browser will show the new yellow background color without a refresh. Or, if you add a new movie to a collection of movies, then every open browser will display the new movie automatically. With Live HTML, users no longer need a refresh button. Changes to an application happen everywhere automatically without any effort. The Meteor framework handles all of the messy details of keeping all of the clients in sync with the server for you. Latency Compensation – When you modify data on the client, these modifications appear as if they happened on the server without any delay. For example, if you create a new movie then the movie appears instantly. However, that is all an illusion. In the background, Meteor updates the database with the new movie. If, for whatever reason, the movie cannot be added to the database then Meteor removes the movie from the client automatically. Latency compensation is extremely important for creating a responsive web application. You want the user to be able to make instant modifications in the browser and the framework to handle the details of updating the database without slowing down the user. Installing Meteor Meteor is licensed under the open-source MIT license and you can start building production apps with the framework right now. Be warned that Meteor is still in the “early preview” stage. It has not reached a 1.0 release. According to the Meteor FAQ, Meteor will reach version 1.0 in “More than a month, less than a year.” Don’t be scared away by that. You should be aware that, unlike most open source projects, Meteor has financial backing. The Meteor project received an $11.2 million round of financing from Andreessen Horowitz. So, it would be a good bet that this project will reach the 1.0 mark. And, if it doesn’t, the framework as it exists right now is still very powerful. Meteor runs on top of Node.js. You write Meteor apps by writing JavaScript which runs both on the client and on the server. You can build Meteor apps on Windows, Mac, or Linux (Although the support for Windows is still officially unofficial). If you want to install Meteor on Windows then download the MSI from the following URL: http://win.meteor.com/ If you want to install Meteor on Mac/Linux then run the following CURL command from your terminal: curl https://install.meteor.com | /bin/sh Meteor will install all of its dependencies automatically including Node.js. However, I recommend that you install Node.js before installing Meteor by installing Node.js from the following address: http://nodejs.org/ If you let Meteor install Node.js then Meteor won’t install NPM which is the standard package manager for Node.js. If you install Node.js and then you install Meteor then you get NPM automatically. Creating a New Meteor App To get a sense of how Meteor works, I am going to walk through the steps required to create a simple Movie database app. Our app will display a list of movies and contain a form for creating a new movie. The first thing that we need to do is create our new Meteor app. Open a command prompt/terminal window and execute the following command: Meteor create MovieApp After you execute this command, you should see something like the following: Follow the instructions: execute cd MovieApp to change to your MovieApp directory, and run the meteor command. Executing the meteor command starts Meteor on port 3000. Open up your favorite web browser and navigate to http://localhost:3000 and you should see the default Meteor Hello World page: Open up your favorite development environment to see what the Meteor app looks like. Open the MovieApp folder which we just created. Here’s what the MovieApp looks like in Visual Studio 2012: Notice that our MovieApp contains three files named MovieApp.css, MovieApp.html, and MovieApp.js. In other words, it contains a Cascading Style Sheet file, an HTML file, and a JavaScript file. Just for fun, let’s see how the Live HTML feature works. Open up multiple browsers and point each browser at http://localhost:3000. Now, open the MovieApp.html page and modify the text “Hello World!” to “Hello Cruel World!” and save the change. The text in all of the browsers should update automatically without a browser refresh. Pretty amazing, right? Controlling Where JavaScript Executes You write a Meteor app using JavaScript. Some of the JavaScript executes on the client (the browser) and some of the JavaScript executes on the server and some of the JavaScript executes in both places. For a super simple app, you can use the Meteor.isServer and Meteor.isClient properties to control where your JavaScript code executes. For example, the following JavaScript contains a section of code which executes on the server and a section of code which executes in the browser: if (Meteor.isClient) { console.log("Hello Browser!"); } if (Meteor.isServer) { console.log("Hello Server!"); } console.log("Hello Browser and Server!"); When you run the app, the message “Hello Browser!” is written to the browser JavaScript console. The message “Hello Server!” is written to the command/terminal window where you ran Meteor. Finally, the message “Hello Browser and Server!” is execute on both the browser and server and the message appears in both places. For simple apps, using Meteor.isClient and Meteor.isServer to control where JavaScript executes is fine. For more complex apps, you should create separate folders for your server and client code. Here are the folders which you can use in a Meteor app: · client – This folder contains any JavaScript which executes only on the client. · server – This folder contains any JavaScript which executes only on the server. · common – This folder contains any JavaScript code which executes on both the client and server. · lib – This folder contains any JavaScript files which you want to execute before any other JavaScript files. · public – This folder contains static application assets such as images. For the Movie App, we need the client, server, and common folders. Delete the existing MovieApp.js, MovieApp.html, and MovieApp.css files. We will create new files in the right locations later in this walkthrough. Combining HTML, CSS, and JavaScript Files Meteor combines all of your JavaScript files, and all of your Cascading Style Sheet files, and all of your HTML files automatically. If you want to create one humongous JavaScript file which contains all of the code for your app then that is your business. However, if you want to build a more maintainable application, then you should break your JavaScript files into many separate JavaScript files and let Meteor combine them for you. Meteor also combines all of your HTML files into a single file. HTML files are allowed to have the following top-level elements: <head> — All <head> files are combined into a single <head> and served with the initial page load. <body> — All <body> files are combined into a single <body> and served with the initial page load. <template> — All <template> files are compiled into JavaScript templates. Because you are creating a single page app, a Meteor app typically will contain a single HTML file for the <head> and <body> content. However, a Meteor app typically will contain several template files. In other words, all of the interesting stuff happens within the <template> files. Displaying a List of Movies Let me start building the Movie App by displaying a list of movies. In order to display a list of movies, we need to create the following four files: · client\movies.html – Contains the HTML for the <head> and <body> of the page for the Movie app. · client\moviesTemplate.html – Contains the HTML template for displaying the list of movies. · client\movies.js – Contains the JavaScript for supplying data to the moviesTemplate. · server\movies.js – Contains the JavaScript for seeding the database with movies. After you create these files, your folder structure should looks like this: Here’s what the client\movies.html file looks like: <head> <title>My Movie App</title> </head> <body> <h1>Movies</h1> {{> moviesTemplate }} </body> Notice that it contains <head> and <body> top-level elements. The <body> element includes the moviesTemplate with the syntax {{> moviesTemplate }}. The moviesTemplate is defined in the client/moviesTemplate.html file: <template name="moviesTemplate"> <ul> {{#each movies}} <li> {{title}} </li> {{/each}} </ul> </template> By default, Meteor uses the Handlebars templating library. In the moviesTemplate above, Handlebars is used to loop through each of the movies using {{#each}}…{{/each}} and display the title for each movie using {{title}}. The client\movies.js JavaScript file is used to bind the moviesTemplate to the Movies collection on the client. Here’s what this JavaScript file looks like: // Declare client Movies collection Movies = new Meteor.Collection("movies"); // Bind moviesTemplate to Movies collection Template.moviesTemplate.movies = function () { return Movies.find(); }; The Movies collection is a client-side proxy for the server-side Movies database collection. Whenever you want to interact with the collection of Movies stored in the database, you use the Movies collection instead of communicating back to the server. The moviesTemplate is bound to the Movies collection by assigning a function to the Template.moviesTemplate.movies property. The function simply returns all of the movies from the Movies collection. The final file which we need is the server-side server\movies.js file: // Declare server Movies collection Movies = new Meteor.Collection("movies"); // Seed the movie database with a few movies Meteor.startup(function () { if (Movies.find().count() == 0) { Movies.insert({ title: "Star Wars", director: "Lucas" }); Movies.insert({ title: "Memento", director: "Nolan" }); Movies.insert({ title: "King Kong", director: "Jackson" }); } }); The server\movies.js file does two things. First, it declares the server-side Meteor Movies collection. When you declare a server-side Meteor collection, a collection is created in the MongoDB database associated with your Meteor app automatically (Meteor uses MongoDB as its database automatically). Second, the server\movies.js file seeds the Movies collection (MongoDB collection) with three movies. Seeding the database gives us some movies to look at when we open the Movies app in a browser. Creating New Movies Let me modify the Movies Database App so that we can add new movies to the database of movies. First, I need to create a new template file – named client\movieForm.html – which contains an HTML form for creating a new movie: <template name="movieForm"> <fieldset> <legend>Add New Movie</legend> <form> <div> <label> Title: <input id="title" /> </label> </div> <div> <label> Director: <input id="director" /> </label> </div> <div> <input type="submit" value="Add Movie" /> </div> </form> </fieldset> </template> In order for the new form to show up, I need to modify the client\movies.html file to include the movieForm.html template. Notice that I added {{> movieForm }} to the client\movies.html file: <head> <title>My Movie App</title> </head> <body> <h1>Movies</h1> {{> moviesTemplate }} {{> movieForm }} </body> After I make these modifications, our Movie app will display the form: The next step is to handle the submit event for the movie form. Below, I’ve modified the client\movies.js file so that it contains a handler for the submit event raised when you submit the form contained in the movieForm.html template: // Declare client Movies collection Movies = new Meteor.Collection("movies"); // Bind moviesTemplate to Movies collection Template.moviesTemplate.movies = function () { return Movies.find(); }; // Handle movieForm events Template.movieForm.events = { 'submit': function (e, tmpl) { // Don't postback e.preventDefault(); // create the new movie var newMovie = { title: tmpl.find("#title").value, director: tmpl.find("#director").value }; // add the movie to the db Movies.insert(newMovie); } }; The Template.movieForm.events property contains an event map which maps event names to handlers. In this case, I am mapping the form submit event to an anonymous function which handles the event. In the event handler, I am first preventing a postback by calling e.preventDefault(). This is a single page app, no postbacks are allowed! Next, I am grabbing the new movie from the HTML form. I’m taking advantage of the template find() method to retrieve the form field values. Finally, I am calling Movies.insert() to insert the new movie into the Movies collection. Here, I am explicitly inserting the new movie into the client-side Movies collection. Meteor inserts the new movie into the server-side Movies collection behind the scenes. When Meteor inserts the movie into the server-side collection, the new movie is added to the MongoDB database associated with the Movies app automatically. If server-side insertion fails for whatever reasons – for example, your internet connection is lost – then Meteor will remove the movie from the client-side Movies collection automatically. In other words, Meteor takes care of keeping the client Movies collection and the server Movies collection in sync. If you open multiple browsers, and add movies, then you should notice that all of the movies appear on all of the open browser automatically. You don’t need to refresh individual browsers to update the client-side Movies collection. Meteor keeps everything synchronized between the browsers and server for you. Removing the Insecure Module To make it easier to develop and debug a new Meteor app, by default, you can modify the database directly from the client. For example, you can delete all of the data in the database by opening up your browser console window and executing multiple Movies.remove() commands. Obviously, enabling anyone to modify your database from the browser is not a good idea in a production application. Before you make a Meteor app public, you should first run the meteor remove insecure command from a command/terminal window: Running meteor remove insecure removes the insecure package from the Movie app. Unfortunately, it also breaks our Movie app. We’ll get an “Access denied” error in our browser console whenever we try to insert a new movie. No worries. I’ll fix this issue in the next section. Creating Meteor Methods By taking advantage of Meteor Methods, you can create methods which can be invoked on both the client and the server. By taking advantage of Meteor Methods you can: 1. Perform form validation on both the client and the server. For example, even if an evil hacker bypasses your client code, you can still prevent the hacker from submitting an invalid value for a form field by enforcing validation on the server. 2. Simulate database operations on the client but actually perform the operations on the server. Let me show you how we can modify our Movie app so it uses Meteor Methods to insert a new movie. First, we need to create a new file named common\methods.js which contains the definition of our Meteor Methods: Meteor.methods({ addMovie: function (newMovie) { // Perform form validation if (newMovie.title == "") { throw new Meteor.Error(413, "Missing title!"); } if (newMovie.director == "") { throw new Meteor.Error(413, "Missing director!"); } // Insert movie (simulate on client, do it on server) return Movies.insert(newMovie); } }); The addMovie() method is called from both the client and the server. This method does two things. First, it performs some basic validation. If you don’t enter a title or you don’t enter a director then an error is thrown. Second, the addMovie() method inserts the new movie into the Movies collection. When called on the client, inserting the new movie into the Movies collection just updates the collection. When called on the server, inserting the new movie into the Movies collection causes the database (MongoDB) to be updated with the new movie. You must add the common\methods.js file to the common folder so it will get executed on both the client and the server. Our folder structure now looks like this: We actually call the addMovie() method within our client code in the client\movies.js file. Here’s what the updated file looks like: // Declare client Movies collection Movies = new Meteor.Collection("movies"); // Bind moviesTemplate to Movies collection Template.moviesTemplate.movies = function () { return Movies.find(); }; // Handle movieForm events Template.movieForm.events = { 'submit': function (e, tmpl) { // Don't postback e.preventDefault(); // create the new movie var newMovie = { title: tmpl.find("#title").value, director: tmpl.find("#director").value }; // add the movie to the db Meteor.call( "addMovie", newMovie, function (err, result) { if (err) { alert("Could not add movie " + err.reason); } } ); } }; The addMovie() method is called – on both the client and the server – by calling the Meteor.call() method. This method accepts the following parameters: · The string name of the method to call. · The data to pass to the method (You can actually pass multiple params for the data if you like). · A callback function to invoke after the method completes. In the JavaScript code above, the addMovie() method is called with the new movie retrieved from the HTML form. The callback checks for an error. If there is an error then the error reason is displayed in an alert (please don’t use alerts for validation errors in a production app because they are ugly!). Summary The goal of this blog post was to provide you with a brief walk through of a simple Meteor app. I showed you how you can create a simple Movie Database app which enables you to display a list of movies and create new movies. I also explained why it is important to remove the Meteor insecure package from a production app. I showed you how to use Meteor Methods to insert data into the database instead of doing it directly from the client. I’m very impressed with the Meteor framework. The support for Live HTML and Latency Compensation are required features for many real world Single Page Apps but implementing these features by hand is not easy. Meteor makes it easy.

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Dynamically loading Assemblies to reduce Runtime Depencies

- by Rick Strahl

I've been working on a request to the West Wind Application Configuration library to add JSON support. The config library is a very easy to use code-first approach to configuration: You create a class that holds the configuration data that inherits from a base configuration class, and then assign a persistence provider at runtime that determines where and how the configuration data is store. Currently the library supports .NET Configuration stores (web.config/app.config), XML files, SQL records and string storage.About once a week somebody asks me about JSON support and I've deflected this question for the longest time because frankly I think that JSON as a configuration store doesn't really buy a heck of a lot over XML. Both formats require the user to perform some fixup of the plain configuration data - in XML into XML tags, with JSON using JSON delimiters for properties and property formatting rules. Sure JSON is a little less verbose and maybe a little easier to read if you have hierarchical data, but overall the differences are pretty minor in my opinion. And yet - the requests keep rolling in.Hard Link Issues in a Component LibraryAnother reason I've been hesitant is that I really didn't want to pull in a dependency on an external JSON library - in this case JSON.NET - into the core library. If you're not using JSON.NET elsewhere I don't want a user to have to require a hard dependency on JSON.NET unless they want to use the JSON feature. JSON.NET is also sensitive to versions and doesn't play nice with multiple versions when hard linked. For example, when you have a reference to V4.4 in your project but the host application has a reference to version 4.5 you can run into assembly load problems. NuGet's Update-Package can solve some of this *if* you can recompile, but that's not ideal for a component that's supposed to be just plug and play. This is no criticism of JSON.NET - this really applies to any dependency that might change. So hard linking the DLL can be problematic for a number reasons, but the primary reason is to not force loading of JSON.NET unless you actually need it when you use the JSON configuration features of the library.Enter Dynamic LoadingSo rather than adding an assembly reference to the project, I decided that it would be better to dynamically load the DLL at runtime and then use dynamic typing to access various classes. This allows me to run without a hard assembly reference and allows more flexibility with version number differences now and in the future.But there are also a couple of downsides:No assembly reference means only dynamic access - no compiler type checking or IntellisenseRequirement for the host application to have reference to JSON.NET or else get runtime errorsThe former is minor, but the latter can be problematic. Runtime errors are always painful, but in this case I'm willing to live with this. If you want to use JSON configuration settings JSON.NET needs to be loaded in the project. If this is a Web project, it'll likely be there already.So there are a few things that are needed to make this work:Dynamically create an instance and optionally attempt to load an Assembly (if not loaded)Load types into dynamic variablesUse Reflection for a few tasks like statics/enumsThe dynamic keyword in C# makes the formerly most difficult Reflection part - method calls and property assignments - fairly painless. But as cool as dynamic is it doesn't handle all aspects of Reflection. Specifically it doesn't deal with object activation, truly dynamic (string based) member activation or accessing of non instance members, so there's still a little bit of work left to do with Reflection.Dynamic Object InstantiationThe first step in getting the process rolling is to instantiate the type you need to work with. This might be a two step process - loading the instance from a string value, since we don't have a hard type reference and potentially having to load the assembly. Although the host project might have a reference to JSON.NET, that instance might have not been loaded yet since it hasn't been accessed yet. In ASP.NET this won't be a problem, since ASP.NET preloads all referenced assemblies on AppDomain startup, but in other executable project, assemblies are just in time loaded only when they are accessed.Instantiating a type is a two step process: Finding the type reference and then activating it. Here's the generic code out of my ReflectionUtils library I use for this:/// <summary> /// Creates an instance of a type based on a string. Assumes that the type's /// </summary> /// <param name="typeName">Common name of the type</param> /// <param name="args">Any constructor parameters</param> /// <returns></returns> public static object CreateInstanceFromString(string typeName, params object[] args) { object instance = null; Type type = null; try { type = GetTypeFromName(typeName); if (type == null) return null; instance = Activator.CreateInstance(type, args); } catch { return null; } return instance; } /// <summary> /// Helper routine that looks up a type name and tries to retrieve the /// full type reference in the actively executing assemblies. /// </summary> /// <param name="typeName"></param> /// <returns></returns> public static Type GetTypeFromName(string typeName) { Type type = null; // Let default name binding find it type = Type.GetType(typeName, false); if (type != null) return type; // look through assembly list var assemblies = AppDomain.CurrentDomain.GetAssemblies(); // try to find manually foreach (Assembly asm in assemblies) { type = asm.GetType(typeName, false); if (type != null) break; } return type; } To use this for loading JSON.NET I have a small factory function that instantiates JSON.NET and sets a bunch of configuration settings on the generated object. The startup code also looks for failure and tries loading up the assembly when it fails since that's the main reason the load would fail. Finally it also caches the loaded instance for reuse (according to James the JSON.NET instance is thread safe and quite a bit faster when cached). Here's what the factory function looks like in JsonSerializationUtils:/// <summary> /// Dynamically creates an instance of JSON.NET /// </summary> /// <param name="throwExceptions">If true throws exceptions otherwise returns null</param> /// <returns>Dynamic JsonSerializer instance</returns> public static dynamic CreateJsonNet(bool throwExceptions = true) { if (JsonNet != null) return JsonNet; lock (SyncLock) { if (JsonNet != null) return JsonNet; // Try to create instance dynamic json = ReflectionUtils.CreateInstanceFromString("Newtonsoft.Json.JsonSerializer"); if (json == null) { try { var ass = AppDomain.CurrentDomain.Load("Newtonsoft.Json"); json = ReflectionUtils.CreateInstanceFromString("Newtonsoft.Json.JsonSerializer"); } catch (Exception ex) { if (throwExceptions) throw; return null; } } if (json == null) return null; json.ReferenceLoopHandling = (dynamic) ReflectionUtils.GetStaticProperty("Newtonsoft.Json.ReferenceLoopHandling", "Ignore"); // Enums as strings in JSON dynamic enumConverter = ReflectionUtils.CreateInstanceFromString("Newtonsoft.Json.Converters.StringEnumConverter"); json.Converters.Add(enumConverter); JsonNet = json; } return JsonNet; }This code's purpose is to return a fully configured JsonSerializer instance. As you can see the code tries to create an instance and when it fails tries to load the assembly, and then re-tries loading.Once the instance is loaded some configuration occurs on it. Specifically I set the ReferenceLoopHandling option to not blow up immediately when circular references are encountered. There are a host of other small config setting that might be useful to set, but the default seem to be good enough in recent versions. Note that I'm setting ReferenceLoopHandling which requires an Enum value to be set. There's no real easy way (short of using the cardinal numeric value) to set a property or pass parameters from static values or enums. This means I still need to use Reflection to make this work. I'm using the same ReflectionUtils class I previously used to handle this for me. The function looks up the type and then uses Type.InvokeMember() to read the static property.Another feature I need is have Enum values serialized as strings rather than numeric values which is the default. To do this I can use the StringEnumConverter to convert enums to strings by adding it to the Converters collection.As you can see there's still a bit of Reflection to be done even in C# 4+ with dynamic, but with a few helpers this process is relatively painless.Doing the actual JSON ConversionFinally I need to actually do my JSON conversions. For the Utility class I need serialization that works for both strings and files so I created four methods that handle these tasks two each for serialization and deserialization for string and file.Here's what the File Serialization looks like:/// <summary> /// Serializes an object instance to a JSON file. /// </summary> /// <param name="value">the value to serialize</param> /// <param name="fileName">Full path to the file to write out with JSON.</param> /// <param name="throwExceptions">Determines whether exceptions are thrown or false is returned</param> /// <param name="formatJsonOutput">if true pretty-formats the JSON with line breaks</param> /// <returns>true or false</returns> public static bool SerializeToFile(object value, string fileName, bool throwExceptions = false, bool formatJsonOutput = false) { dynamic writer = null; FileStream fs = null; try { Type type = value.GetType(); var json = CreateJsonNet(throwExceptions); if (json == null) return false; fs = new FileStream(fileName, FileMode.Create); var sw = new StreamWriter(fs, Encoding.UTF8); writer = Activator.CreateInstance(JsonTextWriterType, sw); if (formatJsonOutput) writer.Formatting = (dynamic)Enum.Parse(FormattingType, "Indented"); writer.QuoteChar = '"'; json.Serialize(writer, value); } catch (Exception ex) { Debug.WriteLine("JsonSerializer Serialize error: " + ex.Message); if (throwExceptions) throw; return false; } finally { if (writer != null) writer.Close(); if (fs != null) fs.Close(); } return true; }You can see more of the dynamic invocation in this code. First I grab the dynamic JsonSerializer instance using the CreateJsonNet() method shown earlier which returns a dynamic. I then create a JsonTextWriter and configure a couple of enum settings on it, and then call Serialize() on the serializer instance with the JsonTextWriter that writes the output to disk. Although this code is dynamic it's still fairly short and readable.For full circle operation here's the DeserializeFromFile() version:/// <summary> /// Deserializes an object from file and returns a reference. /// </summary> /// <param name="fileName">name of the file to serialize to</param> /// <param name="objectType">The Type of the object. Use typeof(yourobject class)</param> /// <param name="binarySerialization">determines whether we use Xml or Binary serialization</param> /// <param name="throwExceptions">determines whether failure will throw rather than return null on failure</param> /// <returns>Instance of the deserialized object or null. Must be cast to your object type</returns> public static object DeserializeFromFile(string fileName, Type objectType, bool throwExceptions = false) { dynamic json = CreateJsonNet(throwExceptions); if (json == null) return null; object result = null; dynamic reader = null; FileStream fs = null; try { fs = new FileStream(fileName, FileMode.Open, FileAccess.Read); var sr = new StreamReader(fs, Encoding.UTF8); reader = Activator.CreateInstance(JsonTextReaderType, sr); result = json.Deserialize(reader, objectType); reader.Close(); } catch (Exception ex) { Debug.WriteLine("JsonNetSerialization Deserialization Error: " + ex.Message); if (throwExceptions) throw; return null; } finally { if (reader != null) reader.Close(); if (fs != null) fs.Close(); } return result; }This code is a little more compact since there are no prettifying options to set. Here JsonTextReader is created dynamically and it receives the output from the Deserialize() operation on the serializer.You can take a look at the full JsonSerializationUtils.cs file on GitHub to see the rest of the operations, but the string operations are very similar - the code is fairly repetitive.These generic serialization utilities isolate the dynamic serialization logic that has to deal with the dynamic nature of JSON.NET, and any code that uses these functions is none the wiser that JSON.NET is dynamically loaded.Using the JsonSerializationUtils WrapperThe final consumer of the SerializationUtils wrapper is an actual ConfigurationProvider, that is responsible for handling reading and writing JSON values to and from files. The provider is simple a small wrapper around the SerializationUtils component and there's very little code to make this work now:The whole provider looks like this:/// <summary> /// Reads and Writes configuration settings in .NET config files and /// sections. Allows reading and writing to default or external files /// and specification of the configuration section that settings are /// applied to. /// </summary> public class JsonFileConfigurationProvider<TAppConfiguration> : ConfigurationProviderBase<TAppConfiguration> where TAppConfiguration: AppConfiguration, new() { /// <summary> /// Optional - the Configuration file where configuration settings are /// stored in. If not specified uses the default Configuration Manager /// and its default store. /// </summary> public string JsonConfigurationFile { get { return _JsonConfigurationFile; } set { _JsonConfigurationFile = value; } } private string _JsonConfigurationFile = string.Empty; public override bool Read(AppConfiguration config) { var newConfig = JsonSerializationUtils.DeserializeFromFile(JsonConfigurationFile, typeof(TAppConfiguration)) as TAppConfiguration; if (newConfig == null) { if(Write(config)) return true; return false; } DecryptFields(newConfig); DataUtils.CopyObjectData(newConfig, config, "Provider,ErrorMessage"); return true; } /// <summary> /// Return /// </summary> /// <typeparam name="TAppConfig"></typeparam> /// <returns></returns> public override TAppConfig Read<TAppConfig>() { var result = JsonSerializationUtils.DeserializeFromFile(JsonConfigurationFile, typeof(TAppConfig)) as TAppConfig; if (result != null) DecryptFields(result); return result; } /// <summary> /// Write configuration to XmlConfigurationFile location /// </summary> /// <param name="config"></param> /// <returns></returns> public override bool Write(AppConfiguration config) { EncryptFields(config); bool result = JsonSerializationUtils.SerializeToFile(config, JsonConfigurationFile,false,true); // Have to decrypt again to make sure the properties are readable afterwards DecryptFields(config); return result; } }This incidentally demonstrates how easy it is to create a new provider for the West Wind Application Configuration component. Simply implementing 3 methods will do in most cases.Note this code doesn't have any dynamic dependencies - all that's abstracted away in the JsonSerializationUtils(). From here on, serializing JSON is just a matter of calling the static methods on the SerializationUtils class.Already, there are several other places in some other tools where I use JSON serialization this is coming in very handy. With a couple of lines of code I was able to add JSON.NET support to an older AJAX library that I use replacing quite a bit of code that was previously in use. And for any other manual JSON operations (in a couple of apps I use JSON Serialization for 'blob' like document storage) this is also going to be handy.Performance?Some of you might be thinking that using dynamic and Reflection can't be good for performance. And you'd be right… In performing some informal testing it looks like the performance of the native code is nearly twice as fast as the dynamic code. Most of the slowness is attributable to type lookups. To test I created a native class that uses an actual reference to JSON.NET and performance was consistently around 85-90% faster with the referenced code. That being said though - I serialized 10,000 objects in 80ms vs. 45ms so this isn't hardly slouchy. For the configuration component speed is not that important because both read and write operations typically happen once on first access and then every once in a while. But for other operations - say a serializer trying to handle AJAX requests on a Web Server one would be well served to create a hard dependency.Dynamic Loading - Worth it?On occasion dynamic loading makes sense. But there's a price to be paid in added code complexity and a performance hit. But for some operations that are not pivotal to a component or application and only used under certain circumstances dynamic loading can be beneficial to avoid having to ship extra files and loading down distributions. These days when you create new projects in Visual Studio with 30 assemblies before you even add your own code, trying to keep file counts under control seems a good idea. It's not the kind of thing you do on a regular basis, but when needed it can be a useful tool. Hopefully some of you find this information useful…© Rick Strahl, West Wind Technologies, 2005-2013Posted in .NET C# Tweet !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

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Dynamically loading Assemblies to reduce Runtime Dependencies

- by Rick Strahl

I've been working on a request to the West Wind Application Configuration library to add JSON support. The config library is a very easy to use code-first approach to configuration: You create a class that holds the configuration data that inherits from a base configuration class, and then assign a persistence provider at runtime that determines where and how the configuration data is store. Currently the library supports .NET Configuration stores (web.config/app.config), XML files, SQL records and string storage.About once a week somebody asks me about JSON support and I've deflected this question for the longest time because frankly I think that JSON as a configuration store doesn't really buy a heck of a lot over XML. Both formats require the user to perform some fixup of the plain configuration data - in XML into XML tags, with JSON using JSON delimiters for properties and property formatting rules. Sure JSON is a little less verbose and maybe a little easier to read if you have hierarchical data, but overall the differences are pretty minor in my opinion. And yet - the requests keep rolling in.Hard Link Issues in a Component LibraryAnother reason I've been hesitant is that I really didn't want to pull in a dependency on an external JSON library - in this case JSON.NET - into the core library. If you're not using JSON.NET elsewhere I don't want a user to have to require a hard dependency on JSON.NET unless they want to use the JSON feature. JSON.NET is also sensitive to versions and doesn't play nice with multiple versions when hard linked. For example, when you have a reference to V4.4 in your project but the host application has a reference to version 4.5 you can run into assembly load problems. NuGet's Update-Package can solve some of this *if* you can recompile, but that's not ideal for a component that's supposed to be just plug and play. This is no criticism of JSON.NET - this really applies to any dependency that might change. So hard linking the DLL can be problematic for a number reasons, but the primary reason is to not force loading of JSON.NET unless you actually need it when you use the JSON configuration features of the library.Enter Dynamic LoadingSo rather than adding an assembly reference to the project, I decided that it would be better to dynamically load the DLL at runtime and then use dynamic typing to access various classes. This allows me to run without a hard assembly reference and allows more flexibility with version number differences now and in the future.But there are also a couple of downsides:No assembly reference means only dynamic access - no compiler type checking or IntellisenseRequirement for the host application to have reference to JSON.NET or else get runtime errorsThe former is minor, but the latter can be problematic. Runtime errors are always painful, but in this case I'm willing to live with this. If you want to use JSON configuration settings JSON.NET needs to be loaded in the project. If this is a Web project, it'll likely be there already.So there are a few things that are needed to make this work:Dynamically create an instance and optionally attempt to load an Assembly (if not loaded)Load types into dynamic variablesUse Reflection for a few tasks like statics/enumsThe dynamic keyword in C# makes the formerly most difficult Reflection part - method calls and property assignments - fairly painless. But as cool as dynamic is it doesn't handle all aspects of Reflection. Specifically it doesn't deal with object activation, truly dynamic (string based) member activation or accessing of non instance members, so there's still a little bit of work left to do with Reflection.Dynamic Object InstantiationThe first step in getting the process rolling is to instantiate the type you need to work with. This might be a two step process - loading the instance from a string value, since we don't have a hard type reference and potentially having to load the assembly. Although the host project might have a reference to JSON.NET, that instance might have not been loaded yet since it hasn't been accessed yet. In ASP.NET this won't be a problem, since ASP.NET preloads all referenced assemblies on AppDomain startup, but in other executable project, assemblies are just in time loaded only when they are accessed.Instantiating a type is a two step process: Finding the type reference and then activating it. Here's the generic code out of my ReflectionUtils library I use for this:/// <summary> /// Creates an instance of a type based on a string. Assumes that the type's /// </summary> /// <param name="typeName">Common name of the type</param> /// <param name="args">Any constructor parameters</param> /// <returns></returns> public static object CreateInstanceFromString(string typeName, params object[] args) { object instance = null; Type type = null; try { type = GetTypeFromName(typeName); if (type == null) return null; instance = Activator.CreateInstance(type, args); } catch { return null; } return instance; } /// <summary> /// Helper routine that looks up a type name and tries to retrieve the /// full type reference in the actively executing assemblies. /// </summary> /// <param name="typeName"></param> /// <returns></returns> public static Type GetTypeFromName(string typeName) { Type type = null; // Let default name binding find it type = Type.GetType(typeName, false); if (type != null) return type; // look through assembly list var assemblies = AppDomain.CurrentDomain.GetAssemblies(); // try to find manually foreach (Assembly asm in assemblies) { type = asm.GetType(typeName, false); if (type != null) break; } return type; } To use this for loading JSON.NET I have a small factory function that instantiates JSON.NET and sets a bunch of configuration settings on the generated object. The startup code also looks for failure and tries loading up the assembly when it fails since that's the main reason the load would fail. Finally it also caches the loaded instance for reuse (according to James the JSON.NET instance is thread safe and quite a bit faster when cached). Here's what the factory function looks like in JsonSerializationUtils:/// <summary> /// Dynamically creates an instance of JSON.NET /// </summary> /// <param name="throwExceptions">If true throws exceptions otherwise returns null</param> /// <returns>Dynamic JsonSerializer instance</returns> public static dynamic CreateJsonNet(bool throwExceptions = true) { if (JsonNet != null) return JsonNet; lock (SyncLock) { if (JsonNet != null) return JsonNet; // Try to create instance dynamic json = ReflectionUtils.CreateInstanceFromString("Newtonsoft.Json.JsonSerializer"); if (json == null) { try { var ass = AppDomain.CurrentDomain.Load("Newtonsoft.Json"); json = ReflectionUtils.CreateInstanceFromString("Newtonsoft.Json.JsonSerializer"); } catch (Exception ex) { if (throwExceptions) throw; return null; } } if (json == null) return null; json.ReferenceLoopHandling = (dynamic) ReflectionUtils.GetStaticProperty("Newtonsoft.Json.ReferenceLoopHandling", "Ignore"); // Enums as strings in JSON dynamic enumConverter = ReflectionUtils.CreateInstanceFromString("Newtonsoft.Json.Converters.StringEnumConverter"); json.Converters.Add(enumConverter); JsonNet = json; } return JsonNet; }This code's purpose is to return a fully configured JsonSerializer instance. As you can see the code tries to create an instance and when it fails tries to load the assembly, and then re-tries loading.Once the instance is loaded some configuration occurs on it. Specifically I set the ReferenceLoopHandling option to not blow up immediately when circular references are encountered. There are a host of other small config setting that might be useful to set, but the default seem to be good enough in recent versions. Note that I'm setting ReferenceLoopHandling which requires an Enum value to be set. There's no real easy way (short of using the cardinal numeric value) to set a property or pass parameters from static values or enums. This means I still need to use Reflection to make this work. I'm using the same ReflectionUtils class I previously used to handle this for me. The function looks up the type and then uses Type.InvokeMember() to read the static property.Another feature I need is have Enum values serialized as strings rather than numeric values which is the default. To do this I can use the StringEnumConverter to convert enums to strings by adding it to the Converters collection.As you can see there's still a bit of Reflection to be done even in C# 4+ with dynamic, but with a few helpers this process is relatively painless.Doing the actual JSON ConversionFinally I need to actually do my JSON conversions. For the Utility class I need serialization that works for both strings and files so I created four methods that handle these tasks two each for serialization and deserialization for string and file.Here's what the File Serialization looks like:/// <summary> /// Serializes an object instance to a JSON file. /// </summary> /// <param name="value">the value to serialize</param> /// <param name="fileName">Full path to the file to write out with JSON.</param> /// <param name="throwExceptions">Determines whether exceptions are thrown or false is returned</param> /// <param name="formatJsonOutput">if true pretty-formats the JSON with line breaks</param> /// <returns>true or false</returns> public static bool SerializeToFile(object value, string fileName, bool throwExceptions = false, bool formatJsonOutput = false) { dynamic writer = null; FileStream fs = null; try { Type type = value.GetType(); var json = CreateJsonNet(throwExceptions); if (json == null) return false; fs = new FileStream(fileName, FileMode.Create); var sw = new StreamWriter(fs, Encoding.UTF8); writer = Activator.CreateInstance(JsonTextWriterType, sw); if (formatJsonOutput) writer.Formatting = (dynamic)Enum.Parse(FormattingType, "Indented"); writer.QuoteChar = '"'; json.Serialize(writer, value); } catch (Exception ex) { Debug.WriteLine("JsonSerializer Serialize error: " + ex.Message); if (throwExceptions) throw; return false; } finally { if (writer != null) writer.Close(); if (fs != null) fs.Close(); } return true; }You can see more of the dynamic invocation in this code. First I grab the dynamic JsonSerializer instance using the CreateJsonNet() method shown earlier which returns a dynamic. I then create a JsonTextWriter and configure a couple of enum settings on it, and then call Serialize() on the serializer instance with the JsonTextWriter that writes the output to disk. Although this code is dynamic it's still fairly short and readable.For full circle operation here's the DeserializeFromFile() version:/// <summary> /// Deserializes an object from file and returns a reference. /// </summary> /// <param name="fileName">name of the file to serialize to</param> /// <param name="objectType">The Type of the object. Use typeof(yourobject class)</param> /// <param name="binarySerialization">determines whether we use Xml or Binary serialization</param> /// <param name="throwExceptions">determines whether failure will throw rather than return null on failure</param> /// <returns>Instance of the deserialized object or null. Must be cast to your object type</returns> public static object DeserializeFromFile(string fileName, Type objectType, bool throwExceptions = false) { dynamic json = CreateJsonNet(throwExceptions); if (json == null) return null; object result = null; dynamic reader = null; FileStream fs = null; try { fs = new FileStream(fileName, FileMode.Open, FileAccess.Read); var sr = new StreamReader(fs, Encoding.UTF8); reader = Activator.CreateInstance(JsonTextReaderType, sr); result = json.Deserialize(reader, objectType); reader.Close(); } catch (Exception ex) { Debug.WriteLine("JsonNetSerialization Deserialization Error: " + ex.Message); if (throwExceptions) throw; return null; } finally { if (reader != null) reader.Close(); if (fs != null) fs.Close(); } return result; }This code is a little more compact since there are no prettifying options to set. Here JsonTextReader is created dynamically and it receives the output from the Deserialize() operation on the serializer.You can take a look at the full JsonSerializationUtils.cs file on GitHub to see the rest of the operations, but the string operations are very similar - the code is fairly repetitive.These generic serialization utilities isolate the dynamic serialization logic that has to deal with the dynamic nature of JSON.NET, and any code that uses these functions is none the wiser that JSON.NET is dynamically loaded.Using the JsonSerializationUtils WrapperThe final consumer of the SerializationUtils wrapper is an actual ConfigurationProvider, that is responsible for handling reading and writing JSON values to and from files. The provider is simple a small wrapper around the SerializationUtils component and there's very little code to make this work now:The whole provider looks like this:/// <summary> /// Reads and Writes configuration settings in .NET config files and /// sections. Allows reading and writing to default or external files /// and specification of the configuration section that settings are /// applied to. /// </summary> public class JsonFileConfigurationProvider<TAppConfiguration> : ConfigurationProviderBase<TAppConfiguration> where TAppConfiguration: AppConfiguration, new() { /// <summary> /// Optional - the Configuration file where configuration settings are /// stored in. If not specified uses the default Configuration Manager /// and its default store. /// </summary> public string JsonConfigurationFile { get { return _JsonConfigurationFile; } set { _JsonConfigurationFile = value; } } private string _JsonConfigurationFile = string.Empty; public override bool Read(AppConfiguration config) { var newConfig = JsonSerializationUtils.DeserializeFromFile(JsonConfigurationFile, typeof(TAppConfiguration)) as TAppConfiguration; if (newConfig == null) { if(Write(config)) return true; return false; } DecryptFields(newConfig); DataUtils.CopyObjectData(newConfig, config, "Provider,ErrorMessage"); return true; } /// <summary> /// Return /// </summary> /// <typeparam name="TAppConfig"></typeparam> /// <returns></returns> public override TAppConfig Read<TAppConfig>() { var result = JsonSerializationUtils.DeserializeFromFile(JsonConfigurationFile, typeof(TAppConfig)) as TAppConfig; if (result != null) DecryptFields(result); return result; } /// <summary> /// Write configuration to XmlConfigurationFile location /// </summary> /// <param name="config"></param> /// <returns></returns> public override bool Write(AppConfiguration config) { EncryptFields(config); bool result = JsonSerializationUtils.SerializeToFile(config, JsonConfigurationFile,false,true); // Have to decrypt again to make sure the properties are readable afterwards DecryptFields(config); return result; } }This incidentally demonstrates how easy it is to create a new provider for the West Wind Application Configuration component. Simply implementing 3 methods will do in most cases.Note this code doesn't have any dynamic dependencies - all that's abstracted away in the JsonSerializationUtils(). From here on, serializing JSON is just a matter of calling the static methods on the SerializationUtils class.Already, there are several other places in some other tools where I use JSON serialization this is coming in very handy. With a couple of lines of code I was able to add JSON.NET support to an older AJAX library that I use replacing quite a bit of code that was previously in use. And for any other manual JSON operations (in a couple of apps I use JSON Serialization for 'blob' like document storage) this is also going to be handy.Performance?Some of you might be thinking that using dynamic and Reflection can't be good for performance. And you'd be right… In performing some informal testing it looks like the performance of the native code is nearly twice as fast as the dynamic code. Most of the slowness is attributable to type lookups. To test I created a native class that uses an actual reference to JSON.NET and performance was consistently around 85-90% faster with the referenced code. This will change though depending on the size of objects serialized - the larger the object the more processing time is spent inside the actual dynamically activated components and the less difference there will be. Dynamic code is always slower, but how much it really affects your application primarily depends on how frequently the dynamic code is called in relation to the non-dynamic code executing. In most situations where dynamic code is used 'to get the process rolling' as I do here the overhead is small enough to not matter.All that being said though - I serialized 10,000 objects in 80ms vs. 45ms so this is hardly slouchy performance. For the configuration component speed is not that important because both read and write operations typically happen once on first access and then every once in a while. But for other operations - say a serializer trying to handle AJAX requests on a Web Server one would be well served to create a hard dependency.Dynamic Loading - Worth it?Dynamic loading is not something you need to worry about but on occasion dynamic loading makes sense. But there's a price to be paid in added code and a performance hit which depends on how frequently the dynamic code is accessed. But for some operations that are not pivotal to a component or application and are only used under certain circumstances dynamic loading can be beneficial to avoid having to ship extra files adding dependencies and loading down distributions. These days when you create new projects in Visual Studio with 30 assemblies before you even add your own code, trying to keep file counts under control seems like a good idea. It's not the kind of thing you do on a regular basis, but when needed it can be a useful option in your toolset… © Rick Strahl, West Wind Technologies, 2005-2013Posted in .NET C# Tweet !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

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Fatal Exception : AsyncTask #1

- by Nadirah Ibtisam

help help..huu Im having a problem here..seems there was no error in codes..but when I run it...and click button to view map consist routing the map..It appers to be close all of sudden..why is that? Please help me friends.. Im developing an app to read my current location and creating route to A position.. here are the codes: public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.map); onNewIntent(getIntent()); Drawable marker = getResources().getDrawable(R.drawable.marker); Drawable marked_places = getResources().getDrawable(R.drawable.feringgi_map); mymap = (MapView)findViewById(R.id.mymap); controller = mymap.getController(); // extract MapView from layout mymap.getController().setZoom(15); mymap.setBuiltInZoomControls(true); mymap.setSatellite(false); // create an overlay that shows our current location myLocationOverlay = new MyLocationOverlay(this, mymap); // add this overlay to the MapView and refresh it mymap.getOverlays().add(myLocationOverlay); mymap.postInvalidate(); myLocationOverlay.runOnFirstFix(new Runnable() { @Override public void run() { controller.setZoom(10); controller.animateTo(myLocationOverlay.getMyLocation()); } }); zoomToMyLocation(); switch(selecteditem) { case 0: switch(selectedsubitem){ case 0://Place A locationManager = (LocationManager) this.getSystemService(Context.LOCATION_SERVICE); locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0, 0, this); Location location = locationManager.getLastKnownLocation(LocationManager.NETWORK_PROVIDER); if (location !=null) { loc=location; } GeoPoint destination = getPoint(3.144341, 101.69541800000002); new BackgroundTask(this, loc, destination).execute(); break; } } class BackgroundTask extends AsyncTask<Void, Void, Void> { private Location location; private GeoPoint dest; private Route route; private Activity activity; private ProgressDialog dialog; private RouteOverlay routeOverlay; public BackgroundTask(Activity activity, Location loc, GeoPoint dest) { location=loc; this.dest=dest; this.activity=activity; dialog = new ProgressDialog(activity); } @Override protected void onPreExecute() { dialog.setCancelable(false); dialog.setTitle("Loading..."); dialog.setMessage("Calculating Route..."); dialog.setButton("Cancel", new DialogInterface.OnClickListener() { public void onClick(final DialogInterface dialog, final int id) { cancel(true); MyMap.this.finish(); }}); dialog.show(); } protected Void doInBackground(Void... params) { if(isNetworkAvailable()) { if(haveInternet()) { try{ route = directions(new GeoPoint((int)(location.getLatitude()*1.0E6),(int)(location.getLongitude()*1.0E6)), dest); } catch (NullPointerException e){ } } else { return null; } } else { return null; } return null; } And this is the log cat (updated).. : 12-10 12:21:15.527: E/AndroidRuntime(10146): FATAL EXCEPTION: AsyncTask #1 12-10 12:21:15.527: E/AndroidRuntime(10146): java.lang.RuntimeException: An error occured while executing doInBackground() 12-10 12:21:15.527: E/AndroidRuntime(10146): at android.os.AsyncTask$3.done(AsyncTask.java:278) 12-10 12:21:15.527: E/AndroidRuntime(10146): at java.util.concurrent.FutureTask$Sync.innerSetException(FutureTask.java:273) 12-10 12:21:15.527: E/AndroidRuntime(10146): at java.util.concurrent.FutureTask.setException(FutureTask.java:124) 12-10 12:21:15.527: E/AndroidRuntime(10146): at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:307) 12-10 12:21:15.527: E/AndroidRuntime(10146): at java.util.concurrent.FutureTask.run(FutureTask.java:137) 12-10 12:21:15.527: E/AndroidRuntime(10146): at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:208) 12-10 12:21:15.527: E/AndroidRuntime(10146): at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1076) 12-10 12:21:15.527: E/AndroidRuntime(10146): at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:569) 12-10 12:21:15.527: E/AndroidRuntime(10146): at java.lang.Thread.run(Thread.java:856) 12-10 12:21:15.527: E/AndroidRuntime(10146): Caused by: java.lang.SecurityException: ConnectivityService: Neither user 10228 nor current process has android.permission.ACCESS_NETWORK_STATE. 12-10 12:21:15.527: E/AndroidRuntime(10146): at android.os.Parcel.readException(Parcel.java:1327) 12-10 12:21:15.527: E/AndroidRuntime(10146): at android.os.Parcel.readException(Parcel.java:1281) 12-10 12:21:15.527: E/AndroidRuntime(10146): at android.net.IConnectivityManager$Stub$Proxy.getActiveNetworkInfo(IConnectivityManager.java:728) 12-10 12:21:15.527: E/AndroidRuntime(10146): at android.net.ConnectivityManager.getActiveNetworkInfo(ConnectivityManager.java:378) 12-10 12:21:15.527: E/AndroidRuntime(10146): at com.madcatworld.testtesttest.MyMap$BackgroundTask.isNetworkAvailable(MyMap.java:488) 12-10 12:21:15.527: E/AndroidRuntime(10146): at com.madcatworld.testtesttest.MyMap$BackgroundTask.doInBackground(MyMap.java:411) 12-10 12:21:15.527: E/AndroidRuntime(10146): at com.madcatworld.testtesttest.MyMap$BackgroundTask.doInBackground(MyMap.java:1) 12-10 12:21:15.527: E/AndroidRuntime(10146): at android.os.AsyncTask$2.call(AsyncTask.java:264) 12-10 12:21:15.527: E/AndroidRuntime(10146): at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:305) 12-10 12:21:15.527: E/AndroidRuntime(10146): ... 5 more This is my manifest file: <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.madcatworld.testtesttest" android:versionCode="1" android:versionName="1.0" > <uses-sdk android:minSdkVersion="8" android:targetSdkVersion="15" /> <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/> <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/> <uses-permission android:name="android.permission.INTERNET"/> <uses-permission android:name="android.permission.CALL_PHONE"/> <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/> <application android:icon="@drawable/ic_launcher" android:label="@string/app_name" android:theme="@style/AppTheme" > <com.google.android.maps.MapView android:id="@+id/mymap" android:clickable="true" android:layout_width="fill_parent" android:layout_height="fill_parent" android:apiKey="XXXX" /> <activity android:theme="@style/StyledIndicators" android:name=".MainTest" android:label="@string/title_activity_main" android:screenOrientation="portrait"> <intent-filter> <action android:name="android.intent.action.MAIN" /> <category android:name="android.intent.category.LAUNCHER" /> </intent-filter> </activity> <uses-library android:name="com.google.android.maps"/> <activity android:name="A" android:screenOrientation="portrait"></activity> <activity android:name="B" android:screenOrientation="portrait"></activity> <activity android:name="C" android:screenOrientation="portrait"></activity> </application> </manifest> For your information, I already put ACCESS_NETWORK_STATE in my manifest.. Can u discover what cause the error? No error in code..but it failed to review my route map..:( Thanks Friends

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XSLT 1.0 recursion

- by DashaLuna

I'm stuck with recursion, was wondering if anyone can help me out with it. I have <Receipts> and <Deposits> elements, that are not verbose, i.e. that a <Receipts> element doesn't have an attribute to show what <Deposit> it is towards. I need to figure out <Deposits> "still amount due" and when a last receipt towards it was paid if any. I'm trying to do it with the following code: The idea was to take 1st deposit and see if there are receipts. If the deposit isn't fully paid and there are more receipts - call that recorsive function with all the same params except now count in following receipt. If there aren't any more receipts or deposit is payed - process it correctly (add required attributes). Otherwise proceed with 2nd deposit. And so on. However, the XSLT crashes with error message that "a processor stack has overflowed - possible cause is infinite template recursion" I would really appreciate any help/teps... I'm not that great with recursion and can't understand why mine here doesn't work. Thanks! :)  <xsl:variable name="depositsClassified"> <xsl:call-template name="classifyDeposits">  <xsl:with-param name="depositsAll" select="$deposits"/> <xsl:with-param name="depositPrevAmount" select="'0'"/>  <xsl:with-param name="receiptsAll" select="$receiptsAsc"/> <xsl:with-param name="receiptCount" select="'1'"/> </xsl:call-template> </xsl:variable> <xsl:template name="classifyDeposits"> <xsl:param name="depositsAll"/> <xsl:param name="depositPrevAmount" select="'0'"/> <xsl:param name="receiptsAll"/> <xsl:param name="receiptCount"/> <xsl:if test="$deposits">  <xsl:variable name="depositFirst" select="$depositsAll[1]"/> <xsl:variable name="receiptSum"> <xsl:choose> <xsl:when test="$receiptsAll"> <xsl:value-of select="sum($receiptsAll[position() <= $receiptCount]/@ActionAmount)"/> </xsl:when> <xsl:otherwise>0</xsl:otherwise> </xsl:choose> </xsl:variable> <xsl:variable name="diff" select="$depositPrevAmount + $depositFirst/@DepositTotalAmount - $receiptSum"/> <xsl:choose> <xsl:when test="$diff > 0 and $receiptCount < $receiptsQuantityOf"> <xsl:call-template name="classifyDeposits"> <xsl:with-param name="depositsAll" select="$depositsAll"/> <xsl:with-param name="depositPrevAmount" select="$depositPrevAmount"/> <xsl:with-param name="receiptsAll" select="$receiptsAll"/> <xsl:with-param name="receiptCount" select="$receiptCount + 1"/> </xsl:call-template> </xsl:when> <xsl:otherwise>  <xsl:apply-templates select="$depositFirst" mode="defineDeposit"> <xsl:with-param name="diff" select="$diff"/> <xsl:with-param name="latestReceiptForDeposit" select="$receiptsAll[position() = $receiptCount]"/> </xsl:apply-templates>  <xsl:call-template name="classifyDeposits"> <xsl:with-param name="depositsAll" select="$depositsAll[position() > 1]"/> <xsl:with-param name="depositPrevAmount" select="$depositPrevAmount + $depositFirst/@DepositTotalAmount"/> <xsl:with-param name="receiptsAll" select="$receiptsAll"/> <xsl:with-param name="receiptCount" select="'1'"/> </xsl:call-template> </xsl:otherwise> </xsl:choose> </xsl:if> </xsl:template>  <xsl:template match="Deposits" mode="defineDeposit"> <xsl:param name="diff"/> <xsl:param name="latestReceiptForDeposit"/> <xsl:choose> <xsl:when test="$diff <= 0"> <xsl:apply-templates select="." mode="addAttrs"> <xsl:with-param name="status" select="'paid'"/> <xsl:with-param name="dueAmount" select="'0'"/> <xsl:with-param name="receipt" select="$latestReceiptForDeposit"/> </xsl:apply-templates> </xsl:when> <xsl:when test="$diff = ./@DepositTotalAmount"> <xsl:apply-templates select="." mode="addAttrs"> <xsl:with-param name="status" select="'due'"/> <xsl:with-param name="dueAmount" select="$diff"/> </xsl:apply-templates> </xsl:when> <xsl:when test="$diff < ./@DepositTotalAmount"> <xsl:apply-templates select="." mode="addAttrs"> <xsl:with-param name="status" select="'outstanding'"/> <xsl:with-param name="dueAmount" select="$diff"/> <xsl:with-param name="receipt" select="$latestReceiptForDeposit"/> </xsl:apply-templates> </xsl:when> <xsl:otherwise/> </xsl:choose> </xsl:template> <xsl:template match="Deposits" mode="addAttrs"> <xsl:param name="status"/> <xsl:param name="dueAmount"/> <xsl:param name="receipt" select="''"/>  <xsl:copy> <xsl:copy-of select="./@*"/> <xsl:attribute name="Status"><xsl:value-of select="$status"/></xsl:attribute> <xsl:attribute name="DueAmount"><xsl:value-of select="$dueAmount"/></xsl:attribute> <xsl:if test="$receipt"> <xsl:attribute name="latestReceiptDate"> <xsl:value-of select="$receipt/@ActionDate"/> </xsl:attribute> </xsl:if> <xsl:copy-of select="./*"/> </xsl:copy> </xsl:template>

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scrolling lags in emacs 23.2 with GTK

- by mefiX

Hey there, I am using emacs 23.2 with the GTK toolkit. I built emacs from source using the following configure-params: ./configure --prefix=/usr --without-makeinfo --without-sound Which builds emacs with the following configuration: Where should the build process find the source code? /home/****/incoming/emacs-23.2 What operating system and machine description files should Emacs use? `s/gnu-linux.h' and `m/intel386.h' What compiler should emacs be built with? gcc -g -O2 -Wdeclaration-after-statement -Wno-pointer-sign Should Emacs use the GNU version of malloc? yes (Using Doug Lea's new malloc from the GNU C Library.) Should Emacs use a relocating allocator for buffers? yes Should Emacs use mmap(2) for buffer allocation? no What window system should Emacs use? x11 What toolkit should Emacs use? GTK Where do we find X Windows header files? Standard dirs Where do we find X Windows libraries? Standard dirs Does Emacs use -lXaw3d? no Does Emacs use -lXpm? yes Does Emacs use -ljpeg? yes Does Emacs use -ltiff? yes Does Emacs use a gif library? yes -lgif Does Emacs use -lpng? yes Does Emacs use -lrsvg-2? no Does Emacs use -lgpm? yes Does Emacs use -ldbus? yes Does Emacs use -lgconf? no Does Emacs use -lfreetype? yes Does Emacs use -lm17n-flt? no Does Emacs use -lotf? yes Does Emacs use -lxft? yes Does Emacs use toolkit scroll bars? yes When I'm scrolling within files of a common size (about 1000 lines) holding the up/down-keys, emacs almost hangs and produces about 50% CPU-load. I use the following plugins: ido linum tabbar auto-complete-config Starting emacs with -q fixes the problem, but then I don't have any plugins. I can't figure out, which part of my .emacs is responsible for this behaviour. Here's an excerpt of my .emacs-file: (require 'ido) (ido-mode 1) (require 'linum) (global-linum-mode 1) (require 'tabbar) (tabbar-mode 1) (tabbar-local-mode 0) (tabbar-mwheel-mode 0) (setq tabbar-buffer-groups-function (lambda () (list "All"))) (global-set-key [M-left] 'tabbar-backward) (global-set-key [M-right] 'tabbar-forward) ;; hide the toolbar (gtk etc.) (tool-bar-mode -1) ;; Mouse scrolling enhancements (setq mouse-wheel-progressive-speed nil) (setq mouse-wheel-scroll-amount '(5 ((shift) . 5) ((control) . nil))) ;; Smart-HOME (defun smart-beginning-of-line () "Forces the cursor to jump to the first none whitespace char of the current line when pressing HOME" (interactive) (let ((oldpos (point))) (back-to-indentation) (and (= oldpos (point)) (beginning-of-line)))) (put 'smart-beginning-of-line 'CUA 'move) (global-set-key [home] 'smart-beginning-of-line) (custom-set-variables ;; custom-set-variables was added by Custom. ;; If you edit it by hand, you could mess it up, so be careful. ;; Your init file should contain only one such instance. ;; If there is more than one, they won't work right. '(column-number-mode t) '(cua-mode t nil (cua-base)) '(custom-buffer-indent 4) '(delete-selection-mode nil) '(display-time-24hr-format t) '(display-time-day-and-date 1) '(display-time-mode t) '(global-font-lock-mode t nil (font-lock)) '(inhibit-startup-buffer-menu t) '(inhibit-startup-screen t) '(pc-select-meta-moves-sexps t) '(pc-select-selection-keys-only t) '(pc-selection-mode t nil (pc-select)) '(scroll-bar-mode (quote right)) '(show-paren-mode t) '(standard-indent 4) '(uniquify-buffer-name-style (quote forward) nil (uniquify))) (setq-default tab-width 4) (setq-default indent-tabs-mode t) (setq c-basic-offset 4) ;; Highlighting of the current line (global-hl-line-mode 1) (set-face-background 'hl-line "#E8F2FE") (defalias 'yes-or-no-p 'y-or-n-p) (display-time) (set-language-environment "Latin-1") ;; Change cursor color according to mode (setq djcb-read-only-color "gray") ;; valid values are t, nil, box, hollow, bar, (bar . WIDTH), hbar, ;; (hbar. HEIGHT); see the docs for set-cursor-type (setq djcb-read-only-cursor-type 'hbar) (setq djcb-overwrite-color "red") (setq djcb-overwrite-cursor-type 'box) (setq djcb-normal-color "black") (setq djcb-normal-cursor-type 'bar) (defun djcb-set-cursor-according-to-mode () "change cursor color and type according to some minor modes." (cond (buffer-read-only (set-cursor-color djcb-read-only-color) (setq cursor-type djcb-read-only-cursor-type)) (overwrite-mode (set-cursor-color djcb-overwrite-color) (setq cursor-type djcb-overwrite-cursor-type)) (t (set-cursor-color djcb-normal-color) (setq cursor-type djcb-normal-cursor-type)))) (add-hook 'post-command-hook 'djcb-set-cursor-according-to-mode) (define-key global-map '[C-right] 'forward-sexp) (define-key global-map '[C-left] 'backward-sexp) (define-key global-map '[s-left] 'windmove-left) (define-key global-map '[s-right] 'windmove-right) (define-key global-map '[s-up] 'windmove-up) (define-key global-map '[s-down] 'windmove-down) (define-key global-map '[S-down-mouse-1] 'mouse-stay-and-copy) (define-key global-map '[C-M-S-down-mouse-1] 'mouse-stay-and-swap) (define-key global-map '[S-mouse-2] 'mouse-yank-and-kill) (define-key global-map '[C-S-down-mouse-1] 'mouse-stay-and-kill) (define-key global-map "\C-a" 'mark-whole-buffer) (custom-set-faces ;; custom-set-faces was added by Custom. ;; If you edit it by hand, you could mess it up, so be careful. ;; Your init file should contain only one such instance. ;; If there is more than one, they won't work right. '(default ((t (:inherit nil :stipple nil :background "#f7f9fa" :foreground "#191919" :inverse-video nil :box nil :strike-through nil :overline nil :underline nil :slant normal :weight normal :height 98 :width normal :foundry "unknown" :family "DejaVu Sans Mono")))) '(font-lock-builtin-face ((((class color) (min-colors 88) (background light)) (:foreground "#642880" :weight bold)))) '(font-lock-comment-face ((((class color) (min-colors 88) (background light)) (:foreground "#3f7f5f")))) '(font-lock-constant-face ((((class color) (min-colors 88) (background light)) (:weight bold)))) '(font-lock-doc-face ((t (:inherit font-lock-string-face :foreground "#3f7f5f")))) '(font-lock-function-name-face ((((class color) (min-colors 88) (background light)) (:foreground "Black" :weight bold)))) '(font-lock-keyword-face ((((class color) (min-colors 88) (background light)) (:foreground "#7f0055" :weight bold)))) '(font-lock-preprocessor-face ((t (:inherit font-lock-builtin-face :foreground "#7f0055" :weight bold)))) '(font-lock-string-face ((((class color) (min-colors 88) (background light)) (:foreground "#0000c0")))) '(font-lock-type-face ((((class color) (min-colors 88) (background light)) (:foreground "#7f0055" :weight bold)))) '(font-lock-variable-name-face ((((class color) (min-colors 88) (background light)) (:foreground "Black")))) '(minibuffer-prompt ((t (:foreground "medium blue")))) '(mode-line ((t (:background "#222222" :foreground "White")))) '(tabbar-button ((t (:inherit tabbar-default :foreground "dark red")))) '(tabbar-button-highlight ((t (:inherit tabbar-default :background "white" :box (:line-width 2 :color "white"))))) '(tabbar-default ((t (:background "gray90" :foreground "gray50" :box (:line-width 3 :color "gray90") :height 100)))) '(tabbar-highlight ((t (:underline t)))) '(tabbar-selected ((t (:inherit tabbar-default :foreground "blue" :weight bold)))) '(tabbar-separator ((t nil))) '(tabbar-unselected ((t (:inherit tabbar-default))))) Any suggestions? Kind regards, mefiX

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On screen orientation loads again data with Async Task

- by Zookey

I make Android application with master/detail pattern. So I have ListActivity class which is FragmentActivity and ListFragment class which is Fragment It all works perfect, but when I change screen orientation it calls again AsyncTask and reload all data. Here is the code for ListActivity class where I handle all logic: @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_list); getActionBar().setDisplayHomeAsUpEnabled(true); getActionBar().setHomeButtonEnabled(true); getActionBar().setTitle("Dnevni horoskop"); if(findViewById(R.id.details_container) != null){ //Tablet mTwoPane = true; //Fragment stuff FragmentManager fm = getSupportFragmentManager(); FragmentTransaction ft = fm.beginTransaction(); DetailsFragment df = new DetailsFragment(); ft.add(R.id.details_container, df); ft.commit(); } pb = (ProgressBar) findViewById(R.id.pb_list); tvNoConnection = (TextView) findViewById(R.id.tv_no_internet); ivNoConnection = (ImageView) findViewById(R.id.iv_no_connection); list = (GridView) findViewById(R.id.gv_list); if(mTwoPane == true){ list.setNumColumns(1); //list.setPadding(16,16,16,16); } adapter = new CustomListAdapter(); list.setOnItemClickListener(new OnItemClickListener() { @Override public void onItemClick(AdapterView<?> arg0, View arg1, int position, long arg3) { pos = position; if(mTwoPane == false){ Bundle bundle = new Bundle(); bundle.putSerializable("zodiac", zodiacFeed); Intent i = new Intent(getApplicationContext(), DetailsActivity.class); i.putExtra("position", position); i.putExtras(bundle); startActivity(i); overridePendingTransition(R.anim.right_in, R.anim.right_out); } else if(mTwoPane == true){ DetailsFragment fragment = (DetailsFragment) getSupportFragmentManager().findFragmentById(R.id.details_container); fragment.setHoroscopeText(zodiacFeed.getItem(position).getText()); fragment.setLargeImage(zodiacFeed.getItem(position).getLargeImage()); fragment.setSign("Dnevni horoskop - "+zodiacFeed.getItem(position).getName()); fragment.setSignDuration(zodiacFeed.getItem(position).getDuration()); // inflate menu from xml /*if(menu != null){ MenuItem item = menu.findItem(R.id.share); Toast.makeText(getApplicationContext(), item.getTitle().toString(), Toast.LENGTH_SHORT).show(); }*/ } } }); if(!Utils.isConnected(getApplicationContext())){ pb.setVisibility(View.GONE); tvNoConnection.setVisibility(View.VISIBLE); ivNoConnection.setVisibility(View.VISIBLE); } //Calling AsyncTask to load data Log.d("TAG", "loading"); HoroscopeAsyncTask task = new HoroscopeAsyncTask(pb); task.execute(); } @Override public void onConfigurationChanged(Configuration newConfig) { // TODO Auto-generated method stub super.onConfigurationChanged(newConfig); } class CustomListAdapter extends BaseAdapter { private LayoutInflater layoutInflater; public CustomListAdapter() { layoutInflater = (LayoutInflater) getBaseContext().getSystemService( Context.LAYOUT_INFLATER_SERVICE); } public int getCount() { // TODO Auto-generated method stub // Set the total list item count return names.length; } public Object getItem(int arg0) { // TODO Auto-generated method stub return null; } public long getItemId(int arg0) { // TODO Auto-generated method stub return 0; } public View getView(int position, View convertView, ViewGroup parent) { // Inflate the item layout and set the views View listItem = convertView; int pos = position; zodiacItem = zodiacList.get(pos); if (listItem == null && mTwoPane == false) { listItem = layoutInflater.inflate(R.layout.list_item, null); } else if(mTwoPane == true){ listItem = layoutInflater.inflate(R.layout.tablet_list_item, null); } // Initialize the views in the layout ImageView iv = (ImageView) listItem.findViewById(R.id.iv_horoscope); iv.setScaleType(ScaleType.CENTER_CROP); TextView tvName = (TextView) listItem.findViewById(R.id.tv_zodiac_name); TextView tvDuration = (TextView) listItem.findViewById(R.id.tv_duration); iv.setImageResource(zodiacItem.getImage()); tvName.setText(zodiacItem.getName()); tvDuration.setText(zodiacItem.getDuration()); Animation animation = AnimationUtils.loadAnimation(getBaseContext(), R.anim.push_up); listItem.startAnimation(animation); animation = null; return listItem; } } private void getHoroscope() { String urlString = "http://balkanandroid.com/download/horoskop/examples/dnevnihoroskop.php"; try { HttpClient client = new DefaultHttpClient(); HttpPost post = new HttpPost(urlString); HttpResponse response = client.execute(post); resEntity = response.getEntity(); response_str = EntityUtils.toString(resEntity); if (resEntity != null) { Log.i("RESPONSE", response_str); runOnUiThread(new Runnable() { public void run() { try { Log.d("TAG", "Response from server : n " + response_str); } catch (Exception e) { e.printStackTrace(); } } }); } } catch (Exception ex) { Log.e("TAG", "error: " + ex.getMessage(), ex); } } private class HoroscopeAsyncTask extends AsyncTask<String, Void, Void> { public HoroscopeAsyncTask(ProgressBar pb1){ pb = pb1; } @Override protected void onPreExecute() { pb.setVisibility(View.VISIBLE); super.onPreExecute(); } @Override protected Void doInBackground(String... params) { getHoroscope(); try { Log.d("TAG", "test u try"); JSONObject jsonObject = new JSONObject(response_str); JSONArray jsonArray = jsonObject.getJSONArray("horoscope"); for(int i=0;i<jsonArray.length();i++){ Log.d("TAG", "test u for"); JSONObject horoscopeObj = jsonArray.getJSONObject(i); String horoscopeSign = horoscopeObj.getString("name_sign"); String horoscopeText = horoscopeObj.getString("txt_hrs"); zodiacItem = new ZodiacItem(horoscopeSign, horoscopeText, duration[i], images[i], largeImages[i]); zodiacList.add(zodiacItem); zodiacFeed.addItem(zodiacItem); //Treba u POJO klasu ubaciti sve. Log.d("TAG", "ZNAK: "+zodiacItem.getName()+" HOROSKOP: "+zodiacItem.getText()); } } catch (JSONException e) { // TODO Auto-generated catch block e.printStackTrace(); Log.e("TAG", "error: " + e.getMessage(), e); } return null; } @Override protected void onPostExecute(Void result) { pb.setVisibility(View.GONE); list.setAdapter(adapter); adapter.notifyDataSetChanged(); super.onPostExecute(result); } } Here is the code for ListFragment class: public class ListFragment extends Fragment { @Override public void onCreate(Bundle savedInstanceState) { // TODO Auto-generated method stub // Retain this fragment across configuration changes. setRetainInstance(true); super.onCreate(savedInstanceState); } @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { // TODO Auto-generated method stub View view = inflater.inflate(R.layout.fragment_list, container, false); return view; } }

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Databinding, using formulas for unusual binding possible?

- by Rattenmann

Edit: added Info for WPF being used I am trying to bind a list of custom objects to a DataGrid. Straight binding seems easy enough, but i need to specify some complex formulas for some extra fields that do not directly show up in my class. Also i want to be able to EDIT the data in the Grid and get updates on related fields. Let me show you an example, because it is really hard to explain. I will simplify it to rooms with items. Each item can be red and blue. My Class looks like this: public class room { public string strRoomName { set; get; } public string strItemname { set; get; } public int intRedItem { set; get; } public int intBlueItem { set; get; } } Now if i use dataTable.ItemSource = myList; i get something like this: nr. | room | name | red | blue 1. living room, ball, 2, 1 2. sleeping room, bunny, 4, 1 3. living room, chair, 3, 2 4. kitchen, ball, 4, 7 5. garage, chair, 1, 4 Now for the complex part i need help with. I want every item to be the same number, red and blue. And because this does not hold true i want to see the "inbalance" per room AND globally like this: nr. | room | name | red | blue | missing | global red | global blue | global missing 1. living room, ball, 2, 1, 1 blue, 6, 7, 1 red 2. sleeping room, bunny, 4, 1, 3 blue, 4, 1, 3 blue 3. living room, chair, 3, 2, 1 blue, 4, 6, 2 red 4. kitchen, ball, 4, 7, 3 red, 6, 7, 1 red 5. garage, chair, 1, 4, 3 red, 4, 6, 2 red As you can see this smeels like excel formulas, i am unsure how to handle this in c# code however. You can also see i need to use data in the same row, but also get data from other rows that match one propertiy (the items name). Also if i change the blue value=1 in line 1 to value=2, i want line 1 to read like this: 1. living room, ball, 2, 2, even, 6, 8, 2 red and of corse line 4 needs to change to: 4. kitchen, ball, 4, 7, 3 red, 6, 8, 2 red As i said, this smells like excel, that's why i am really upset about myself not finding an easy solution. Surely enough c# offers some way to handle this stuff, right? Disclaimer: It is totally possible that i need a complete differend approach, pointing that out ot me is perfectly fine. Be it other ways to handle this, or a better way to structure my class. I am ok with every way to handle this as it is for learning purposes. I am simply doing programms for fun next to my college and just so happen to hit these kinda things that bug me out because i don't find a clean solution. And then i neglect my studies because i want to solve my (unreleated to studys,...) issue. Just can't stand having unsolved coding stuff around, don't judge me! ;-) And big thanks in advance if you have gotten this far in my post. It sure must be confusing with all those reds and blues. Edit: After reading trough your answers and testing my skills to implement your hints, i now have the following code as my class: public class RoomList : ObservableCollection<room> { public RoomList() : base() { Add(new room() { strRoomName = "living room", strItemname = "ball", intRedItem = 2, intBlueItem = 1 }); Add(new room() { strRoomName = "sleeping room", strItemname = "bunny", intRedItem = 4, intBlueItem = 1 }); Add(new room() { strRoomName = "living room", strItemname = "chair", intRedItem = 3, intBlueItem = 2 }); Add(new room() { strRoomName = "kitchen", strItemname = "ball", intRedItem = 4, intBlueItem = 7 }); Add(new room() { strRoomName = "garage", strItemname = "chair", intRedItem = 1, intBlueItem = 4 }); } } //rooms public class room : INotifyPropertyChanged { public string strRoomName { set; get; } public string strItemname { set; get; } public int intRedItem { get { return intRedItem; } set { intRedItem = value; NotifyPropertyChanged("intRedItem", "strMissing"); } } public int intBlueItem { get { return intBlueItem; } set { intBlueItem = value; NotifyPropertyChanged("intBlueItem", "strMissing"); } } public string strMissing { get { int missingCount = intRedItem - intBlueItem; return missingCount == 0 ? "Even" : missingCount.ToString(); } } public event PropertyChangedEventHandler PropertyChanged; public void NotifyPropertyChanged(params string[] propertyNames) { if (PropertyChanged != null) { foreach (string propertyName in propertyNames) { PropertyChanged(this, new PropertyChangedEventArgs(propertyName)); } } } } I got the "missing" field working right away, thanks alot for that tip. It really was as easy as i imagined and will be of great use for future projects. Still two (three maybe....) things i am missing tho. The above code terminates with a "System.StackOverflowException" in the setter of intRedItem and intBlueItem. I fail to see the error, that could be due to being 4:30am here, or my lack of understanding. Second issue: I followed the link to ObservableCollections as you can see from my code above. Yet i am unsure how to actually use that collection. Putting it as DataContent like suggested on that page shows a missing ressource. Adding it as a ressource like listed there crashes my VSExpress designer and leads to the programm not starting. So for now i am still using my old approach of a list like this: listRooms.Add(new room() { strRoomName = "living room", strItemname = "ball", intRedItem = 2, intBlueItem = 1 }); listRooms.Add(new room() { strRoomName = "sleeping room", strItemname = "bunny", intRedItem = 4, intBlueItem = 1 }); listRooms.Add(new room() { strRoomName = "living room", strItemname = "chair", intRedItem = 3, intBlueItem = 2 }); listRooms.Add(new room() { strRoomName = "kitchen", strItemname = "ball", intRedItem = 4, intBlueItem = 7 }); listRooms.Add(new room() { strRoomName = "garage", strItemname = "chair", intRedItem = 1, intBlueItem = 4 }); datagridRooms.ItemsSource = listRooms; And lastly: When testing before adding the notifyevents i tried to implement a proterty that looped trough the other objects, without any luck. The "missingItem" property worked so easy, yet it only tries to access "it's own" properties kind of. I need to access other objects, like "all objects that have the same room value". The idea behind this is that i am trying to calculate a value from other objects without even having those objects yet, at least in my logic. Where is the flaw in my thinking? Those 5 objects are added and created (?) one after another. So if the first tries to set it's "all red balls in my room AND all other rooms" value,.. how could it know about the balls in the kitchen, that get added as 4th object? So far so good tho, got on the right track i think. Just need some sleep first.

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How to sort & Group in Android?

- by crickpatel0024

I have ArrayList and I want to sort and group all data by header in Android. How it is possible in Android? please help me.below me from owner And set header Me And Joe Manager From owner And set Header in listview. How to do that in Android? My code in below:: public class Request extends Activity { private String assosiatetoken; private ArrayList<All_Request_data_dto> list = new ArrayList<All_Request_data_dto>(); ListView lv; Button back; private Spinner spndata; String[] reqspinner = { "Request Date", "Last Update", "Type", "Owner", "State" }; ArrayAdapter<String> adapter; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.request); assosiatetoken = MyApplication.getToken(); new doinbackground(this).execute(); back = (Button) findViewById(R.id.button1); spndata = (Spinner) findViewById(R.id.list_all_quize_req); adapter = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_item, reqspinner); spndata.setAdapter(adapter); lv = (ListView) findViewById(R.id.listrequestdata); lv.setOnItemClickListener(new OnItemClickListener() { public void onItemClick(AdapterView<?> a, View v, int position, long id) { Intent edit = new Intent(Request.this, Request_webview.class); // edit.putExtra("Cat_url", url_link); startActivity(edit); } }); spndata.setOnItemSelectedListener(new OnItemSelectedListener() { public void onItemSelected(AdapterView<?> arg0, View arg1, int position, long arg3) { switch (position) { case 0: list = DBAdpter.requestUserData(assosiatetoken); Collections.sort(list, byDate1); // Collections.reverse(list); for (int i = 0; i < list.size(); i++) { if (list.get(i).submitDate != null) { lv.setAdapter(new MyListAdapter( getApplicationContext(), list)); } } break; case 1: list = DBAdpter.requestUserData(assosiatetoken); Collections.sort(list, byDate); for (int i = 0; i < list.size(); i++) { if (list.get(i).lastModifiedDate != null) { lv.setAdapter(new MyListAdapter( getApplicationContext(), list)); } } break; case 2: list = DBAdpter.requestUserData(assosiatetoken); Collections.sort(list, byDate3); // Collections.reverse(list); for (int i = 0; i < list.size(); i++) { if (list.get(i).state != null) { lv.setAdapter(new MyListAdapter( getApplicationContext(), list)); } } break; case 3: list = DBAdpter.requestUserData(assosiatetoken); for (int i = 0; i < list.size(); i++) { lv.setAdapter(new MyListAdapter( getApplicationContext(), list)); } break; default: break; } } public void onNothingSelected(AdapterView<?> arg0) { } }); back.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { finish(); } }); } static final Comparator<All_Request_data_dto> byDate = new Comparator<All_Request_data_dto>() { SimpleDateFormat sdf = new SimpleDateFormat("MM/dd/yyyy hh:mm:ss a"); public int compare(All_Request_data_dto ord1, All_Request_data_dto ord2) { java.util.Date d1 = null; java.util.Date d2 = null; try { d1 = sdf.parse(ord1.lastModifiedDate); d2 = sdf.parse(ord2.lastModifiedDate); } catch (java.text.ParseException e) { // TODO Auto-generated catch block e.printStackTrace(); } return (d1.getTime() > d2.getTime() ? -1 : 1); // descending // return (d1.getTime() > d2.getTime() ? 1 : -1); //ascending } }; static final Comparator<All_Request_data_dto> byDate1 = new Comparator<All_Request_data_dto>() { SimpleDateFormat sdf = new SimpleDateFormat("MM/dd/yyyy hh:mm:ss a"); public int compare(All_Request_data_dto ord1, All_Request_data_dto ord2) { java.util.Date d1 = null; java.util.Date d2 = null; try { d1 = sdf.parse(ord1.submitDate); d2 = sdf.parse(ord2.submitDate); } catch (java.text.ParseException e) { // TODO Auto-generated catch block e.printStackTrace(); } return (d1.getTime() > d2.getTime() ? -1 : 1); // descending // return (d1.getTime() > d2.getTime() ? 1 : -1); //ascending } }; static final Comparator<All_Request_data_dto> byDate3 = new Comparator<All_Request_data_dto>() { public int compare(All_Request_data_dto ord1, All_Request_data_dto ord2) { String d1 = null; String d2 = null; d1 = ord1.state; d2 = ord2.state; return d1.compareToIgnoreCase(d2); } }; class doinbackground extends AsyncTask<Void, Void, Void> { ProgressDialog pd; private Context ctx; public doinbackground(Context c) { ctx = c; } @Override protected void onPreExecute() { super.onPreExecute(); pd = new ProgressDialog(ctx); pd.setMessage("Loading..."); pd.show(); } @Override protected Void doInBackground(Void... Params) { return null; } @Override protected void onPostExecute(Void result) { super.onPostExecute(result); pd.cancel(); } } public class MyListAdapter extends BaseAdapter { private ArrayList<All_Request_data_dto> list; public MyListAdapter(Context mContext, ArrayList<All_Request_data_dto> list) { this.list = list; } public int getCount() { return list.size(); } public All_Request_data_dto getItem(int position) { return list.get(position); } public long getItemId(int position) { return position; } public View getView(int position, View convertView, ViewGroup parent) { // if (convertView == null) { LayoutInflater inflator = (LayoutInflater) getSystemService(LAYOUT_INFLATER_SERVICE); convertView = inflator.inflate(R.layout.custom_request_data, null); TextView req_id = (TextView) convertView.findViewById(R.id.req_txt); TextView date = (TextView) convertView.findViewById(R.id.date_txt); TextView owner = (TextView) convertView .findViewById(R.id.owner_txt); TextView state = (TextView) convertView .findViewById(R.id.state_txt); req_id.setText(list.get(position).requestId + " - " + list.get(position).title); date.setText(list.get(position).lastModifiedDate + " - " + list.get(position).submitDate); owner.setText(list.get(position).owner); state.setText(list.get(position).state); // } return convertView; } } }

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NetBeans Development 7 - Windows 7 64-bit … JNI native calls ... a how to guide

- by CirrusFlyer

I provide this for you to hopefully save you some time and pain. As part of my expereince in getting to know NB Development v7 on my Windows 64-bit workstation I found another frustrating adventure in trying to get the JNI (Java Native Interface) abilities up and working in my project. As such, I am including a brief summary of steps required (as all the documentation I found was completely incorrect for these versions of Windows and NetBeans on how to do JNI). It took a couple of days of experimentation and reviewing every webpage I could find that included these technologies as keyword searches. Yuk!! Not fun. To begin, as NetBeans Development is "all about modules" if you are reading this you probably have a need for one, or more, of your modules to perform JNI calls. Most of what is available on this site or the Internet in general (not to mention the help file in NB7) is either completely wrong for these versions, or so sparse as to be essentially unuseful to anyone other than a JNI expert. Here is what you are looking for ... the "cut to the chase" - "how to guide" to get a JNI call up and working on your NB7 / Windows 64-bit box. 1) From within your NetBeans Module (not the host appliation) declair your native method(s) and make sure you can compile the Java source without errors. Example: package org.mycompanyname.nativelogic; public class NativeInterfaceTest { static { try { if (System.getProperty( "os.arch" ).toLowerCase().equals( "amd64" ) ) System.loadLibrary( <64-bit_folder_name_on_file_system>/<file_name.dll> ); else System.loadLibrary( <32-bit_folder_name_on_file_system>/<file_name.dll> ); } catch (SecurityException se) {} catch (UnsatisfieldLinkError ule) {} catch (NullPointerException npe) {} } public NativeInterfaceTest() {} native String echoString(String s); } Take notice to the fact that we only load the Assembly once (as it's in a static block), because othersise you will throw exceptions if attempting to load it again. Also take note of our single (in this example) native method titled "echoString". This is the method that our C / C++ application is going to implement, then via the majic of JNI we'll call from our Java code. 2) If using a 64-bit version of Windows (which we are here) we need to open a 64-bit Visual Studio Command Prompt (versus the standard 32-bit version), and execute the "vcvarsall" BAT file, along with an "amd64" command line argument, to set the environment up for 64-bit tools. Example: <path_to_Microsoft_Visual_Studio_10.0>/VC/vcvarsall.bat amd64 Take note that you can use any version of the C / C++ compiler from Microsoft you wish. I happen to have Visual Studio 2005, 2008, and 2010 installed on my box so I chose to use "v10.0" but any that support 64-bit development will work fine. The other important aspect here is the "amd64" param. 3) In the Command Prompt change drives \ directories on your computer so that you are at the root of the fully qualified Class location on the file system that contains your native method declairation. Example: The fully qualified class name for my natively declair method is "org.mycompanyname.nativelogic.NativeInterfaceTest". As we successfully compiled our Java in Step 1 above, we should find it contained in our NetBeans Module something similar to the following: "/build/classes/org/mycompanyname/nativelogic/NativeInterfaceTest.class" We need to make sure our Command Prompt sets, as the current directly, "/build/classes" because of our next step. 4) In this step we'll create our C / C++ Header file that contains the JNI required statments. Type the following in the Command Prompt: javah -jni org.mycompanyname.nativelogic.NativeInterfaceTest and hit enter. If you receive any kind of error that states this is an unrecognized command that simply means your Windows computer does not know the PATH to that command (it's in your /bin folder). Either run the command from there, or include the fully qualified path name when invoking this application, or set your computer's PATH environmental variable to include that path in its search. This should produce a file called "org_mycompanyname_nativelogic_NativeInterfaceTest.h" ... a C Header file. I'd make a copy of this in case you need a backup later. 5) Edit the NativeInterfaceTest.h header file and include an implementation for the echoString() method. Example: JNIEXPORT jstring JNICALL Java_org_mycompanyname_nativelogic_NativeInterfaceTest_echoString (JNIEnv *env, jobject jobj, jstring js) { return((*env)->NewStringUTF(env, "My JNI is up and working after lots of research")); } Notice how you can't simply return a normal Java String (because you're in C at the moment). You have to tell the passed in JVM variable to create a Java String for you that will be returned back. Check out the following Oracle web page for other data types and how to create them for JNI purposes. 6) Close and Save your changes to the Header file. Now that you've added an implementation to the Header change the file extention from ".h" to ".c" as it's now a C source code file that properly implements the JNI required interface. Example: NativeInterfaceTest.c 7) We need to compile the newly created source code file and Link it too. From within the Command Prompt type the following: cl /I"path_to_my_jdks_include_folder" /I"path_to_my_jdks_include_win32_folder" /D:AMD64=1 /LD NativeInterfaceTest.c /FeNativeInterfaceTest.dll /link /machine:x64 Example: cl /I"D:/Program Files/Java/jdk1.6.0_21/include" /I"D:/Program Files/java/jdk1.6.0_21/include/win32" /D:AMD64=1 /LD NativeInterfaceTest.c /FeNativeInterfaceTest.dll /link /machine:x64 Notice the quotes around the paths to the 'include" and 'include/win32' folders is required because I have spaces in my folder names ... 'Program Files'. You can include them if you have no spaces without problems, but they are mandatory if you have spaces when using a command prompt. This will generate serveral files, but it's the DLL we're interested in. This is what the System.loadLirbary() java method is looking for. 8) Congratuations! You're at the last step. Simply take the DLL Assembly and paste it at the following location: <path_of_NetBeansProjects_folder>/<project_name>/<module_name>/build/cluster/modules/lib/x64 Note that you'll probably have to create the "lib" and "x64" folders. Example: C:\Users\<user_name>\Documents\NetBeansProjects\<application_name>\<module_name>\build\cluster\modules\lib\x64\NativeInterfaceTest.dll Java code ... notice how we don't inlude the ".dll" file extension in the loadLibrary() call? System.loadLibrary( "/x64/NativeInterfaceTest" ); Now, in your Java code you can create a NativeInterfaceTest object and call the echoString() method and it will return the String value you typed in the NativeInterfaceTest.c source code file. Hopefully this will save you the brain damage I endured trying to figure all this out on my own. Good luck and happy coding!

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Android - doInBackground() error in AsyncTask

- by AimanB

What my app here basically does is it captures a photo or import from gallery, and when the Upload button is pressed, the image will be uploaded to a localhost server. Before I implemented AsyncTask into the process, it doesn't have any problem uploading whatsoever. Now that I've put AsyncTask, everything went wrong. I don't know which part that I do wrong in this phase. This is what logcat shows when I try to upload an image file: 10-28 17:23:25.989: E/AndroidRuntime(3356): FATAL EXCEPTION: AsyncTask #5 10-28 17:23:25.989: E/AndroidRuntime(3356): java.lang.RuntimeException: An error occured while executing doInBackground() 10-28 17:23:25.989: E/AndroidRuntime(3356): at android.os.AsyncTask$3.done(AsyncTask.java:299) 10-28 17:23:25.989: E/AndroidRuntime(3356): at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:352) 10-28 17:23:25.989: E/AndroidRuntime(3356): at java.util.concurrent.FutureTask.setException(FutureTask.java:219) 10-28 17:23:25.989: E/AndroidRuntime(3356): at java.util.concurrent.FutureTask.run(FutureTask.java:239) 10-28 17:23:25.989: E/AndroidRuntime(3356): at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:230) 10-28 17:23:25.989: E/AndroidRuntime(3356): at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1080) 10-28 17:23:25.989: E/AndroidRuntime(3356): at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:573) 10-28 17:23:25.989: E/AndroidRuntime(3356): at java.lang.Thread.run(Thread.java:856) 10-28 17:23:25.989: E/AndroidRuntime(3356): Caused by: java.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare() 10-28 17:23:25.989: E/AndroidRuntime(3356): at android.os.Handler.<init>(Handler.java:197) 10-28 17:23:25.989: E/AndroidRuntime(3356): at android.os.Handler.<init>(Handler.java:111) 10-28 17:23:25.989: E/AndroidRuntime(3356): at android.widget.Toast$TN.<init>(Toast.java:324) 10-28 17:23:25.989: E/AndroidRuntime(3356): at android.widget.Toast.<init>(Toast.java:91) 10-28 17:23:25.989: E/AndroidRuntime(3356): at android.widget.Toast.makeText(Toast.java:238) 10-28 17:23:25.989: E/AndroidRuntime(3356): at com.aiman.webshopper.UploadImageActivity$1execMultiPostAsync.doInBackground(UploadImageActivity.java:268) 10-28 17:23:25.989: E/AndroidRuntime(3356): at com.aiman.webshopper.UploadImageActivity$1execMultiPostAsync.doInBackground(UploadImageActivity.java:1) 10-28 17:23:25.989: E/AndroidRuntime(3356): at android.os.AsyncTask$2.call(AsyncTask.java:287) 10-28 17:23:25.989: E/AndroidRuntime(3356): at java.util.concurrent.FutureTask.run(FutureTask.java:234) This is my code for the Upload activity: public class UploadImageActivity extends Activity implements OnItemSelectedListener { InputStream inputStream; private ImageView imageView; String the_string_response; private static final int SELECT_PICTURE = 0; private static final int CAMERA_REQUEST = 1888; private static final String SERVER_UPLOAD_URI = "...myserver.php"; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_upload_image); imageView = (ImageView) findViewById(R.id.imgUpload); } public void capturePhoto(View view) { Intent cameraIntent = new Intent( android.provider.MediaStore.ACTION_IMAGE_CAPTURE); File f = new File(android.os.Environment.getExternalStorageDirectory(), "temp.jpg"); cameraIntent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(f)); startActivityForResult(cameraIntent, CAMERA_REQUEST); } public void pickPhoto(View view) { // TODO: launch the photo picker Intent intent = new Intent(); intent.setType("image/*"); intent.setAction(Intent.ACTION_GET_CONTENT); startActivityForResult(Intent.createChooser(intent, "Select Picture"), SELECT_PICTURE); } @Override protected void onActivityResult(int requestCode, int resultCode, Intent data) { super.onActivityResult(requestCode, resultCode, data); if (requestCode == CAMERA_REQUEST && resultCode == RESULT_OK) { File f = new File(Environment.getExternalStorageDirectory() .toString()); for (File temp : f.listFiles()) { if (temp.getName().equals("temp.jpg")) { f = temp; break; } } try { BitmapFactory.Options bitmapOptions = new BitmapFactory.Options(); Bitmap bitmap = BitmapFactory.decodeFile(f.getAbsolutePath(), bitmapOptions); imageView.setImageBitmap(bitmap); String path = android.os.Environment .getExternalStorageDirectory() + File.separator + "Phoenix" + File.separator + "default"; f.delete(); OutputStream outFile = null; File file = new File(path, String.valueOf(System .currentTimeMillis()) + ".jpg"); try { outFile = new FileOutputStream(file); bitmap.compress(Bitmap.CompressFormat.JPEG, 85, outFile); outFile.flush(); outFile.close(); } catch (FileNotFoundException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } catch (Exception e) { e.printStackTrace(); } } catch (Exception e) { e.printStackTrace(); } } if (requestCode == SELECT_PICTURE && resultCode == RESULT_OK) { Bitmap bitmap = getPath(data.getData()); imageView.setImageBitmap(bitmap); } } private Bitmap getPath(Uri uri) { String[] projection = { MediaStore.Images.Media.DATA }; Cursor cursor = getContentResolver().query(uri, projection, null, null, null); int column_index = cursor.getColumnIndexOrThrow(projection[0]); cursor.moveToFirst(); String filePath = cursor.getString(column_index); cursor.close(); // Convert file path into bitmap image using below line. Bitmap bitmap = BitmapFactory.decodeFile(filePath); return bitmap; } public void uploadPhoto(View view) { try { executeMultipartPost(); } catch (Exception e) { e.printStackTrace(); } } public void executeMultipartPost() throws Exception { class execMultiPostAsync extends AsyncTask<String, Void, String>{ @Override protected String doInBackground(String... params){ // Choose image here BitmapDrawable drawable = (BitmapDrawable) imageView.getDrawable(); Bitmap bitmap = drawable.getBitmap(); ByteArrayOutputStream stream = new ByteArrayOutputStream(); bitmap.compress(Bitmap.CompressFormat.JPEG, 50, stream); // compress to // which // format // you want. byte[] byte_arr = stream.toByteArray(); String image_str = Base64.encodeBytes(byte_arr); ArrayList<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(); nameValuePairs.add(new BasicNameValuePair("image", image_str)); try { HttpClient httpclient = new DefaultHttpClient(); /* * HttpPost(parameter): Server URI */ HttpPost httppost = new HttpPost(SERVER_UPLOAD_URI); httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs)); HttpResponse response = httpclient.execute(httppost); the_string_response = convertResponseToString(response); } catch (Exception e) { Toast.makeText(UploadImageActivity.this, "ERROR " + e.getMessage(), Toast.LENGTH_LONG).show(); System.out.println("Error in http connection " + e.toString()); } return the_string_response; } @Override protected void onPostExecute(String result) { super.onPostExecute(result); Toast.makeText(UploadImageActivity.this, "Response " + result, Toast.LENGTH_LONG) .show(); } public String convertResponseToString(HttpResponse response) throws IllegalStateException, IOException { String res = ""; StringBuffer buffer = new StringBuffer(); inputStream = response.getEntity().getContent(); int contentLength = (int) response.getEntity().getContentLength(); // getting // content // lengt Toast.makeText(UploadImageActivity.this, "contentLength : " + contentLength, Toast.LENGTH_LONG).show(); if (contentLength < 0) { } else { byte[] data = new byte[512]; int len = 0; try { while (-1 != (len = inputStream.read(data))) { buffer.append(new String(data, 0, len)); // converting to // string and // appending to // stringbuffer } } catch (IOException e) { e.printStackTrace(); } try { inputStream.close(); // closing the stream } catch (IOException e) { e.printStackTrace(); } res = buffer.toString(); // converting stringbuffer to string Toast.makeText(UploadImageActivity.this, "Result : " + res, Toast.LENGTH_LONG).show(); // System.out.println("Response => " + // EntityUtils.toString(response.getEntity())); } return res; } } execMultiPostAsync exec = new execMultiPostAsync(); exec.execute(); } } Can someone please check if I put the AsyncTask task correctly in this activity? I think I've made a mistake somewhere.

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Array structure returned by Yii's model

- by user1104955

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org-sort multi: date/time (?d ?t) | priority (?p) | title (?a)

- by lawlist

Is anyone aware of an org-sort function / modification that can refile / organize a group of TODO so that it sorts them by three (3) criteria: first sort by due date, second sort by priority, and third sort by by title of the task? EDIT: I believe that org-sort by deadline (?d) has a bug that cannot properly handle undated tasks. I am working on a workaround (i.e., moving the undated todo to a different heading before the deadline (?d) sort occurs), but perhaps the best thing to do would be to try and fix the original sorting function. Development of the workaround can be found in this thread (i.e., moving the undated tasks to a different heading in one fell swoop): How to automate org-refile for multiple todo EDIT: Apparently, the following code (ancient history) that I found on the internet was eventually modified and included as a part of org-sort-entries. Unfortunately, undated todo are not properly sorted when sorting by deadline -- i.e., they are mixed in with the dated todo. ;; multiple sort (defun org-sort-multi (&rest sort-types) "Multiple sorts on a certain level of an outline tree, or plain list items. SORT-TYPES is a list where each entry is either a character or a cons pair (BOOL . CHAR), where BOOL is whether or not to sort case-sensitively, and CHAR is one of the characters defined in `org-sort-entries-or-items'. Entries are applied in back to front order. Example: To sort first by TODO status, then by priority, then by date, then alphabetically (case-sensitive) use the following call: (org-sort-multi '(?d ?p ?t (t . ?a)))" (interactive) (dolist (x (nreverse sort-types)) (when (char-valid-p x) (setq x (cons nil x))) (condition-case nil (org-sort-entries (car x) (cdr x)) (error nil)))) ;; sort current level (defun lawlist-sort (&rest sort-types) "Sort the current org level. SORT-TYPES is a list where each entry is either a character or a cons pair (BOOL . CHAR), where BOOL is whether or not to sort case-sensitively, and CHAR is one of the characters defined in `org-sort-entries-or-items'. Entries are applied in back to front order. Defaults to \"?o ?p\" which is sorted by TODO status, then by priority" (interactive) (when (equal mode-name "Org") (let ((sort-types (or sort-types (if (or (org-entry-get nil "TODO") (org-entry-get nil "PRIORITY")) '(?d ?t ?p) ;; date, time, priority '((nil . ?a)))))) (save-excursion (outline-up-heading 1) (let ((start (point)) end) (while (and (not (bobp)) (not (eobp)) (<= (point) start)) (condition-case nil (outline-forward-same-level 1) (error (outline-up-heading 1)))) (unless (> (point) start) (goto-char (point-max))) (setq end (point)) (goto-char start) (apply 'org-sort-multi sort-types) (goto-char end) (when (eobp) (forward-line -1)) (when (looking-at "^\\s-*$") ;; (delete-line) ) (goto-char start) ;; (dotimes (x ) (org-cycle)) ))))) EDIT: Here is a more modern version of multi-sort, which is likely based upon further development of the above-code: (defun org-sort-all () (interactive) (save-excursion (goto-char (point-min)) (while (re-search-forward "^\* " nil t) (goto-char (match-beginning 0)) (condition-case err (progn (org-sort-entries t ?a) (org-sort-entries t ?p) (org-sort-entries t ?o) (forward-line)) (error nil))) (goto-char (point-min)) (while (re-search-forward "\* PROJECT " nil t) (goto-char (line-beginning-position)) (ignore-errors (org-sort-entries t ?a) (org-sort-entries t ?p) (org-sort-entries t ?o)) (forward-line)))) EDIT: The best option will be to fix sorting of deadlines (?d) so that undated todo are moved to the bottom of the outline, instead of mixed in with the dated todo. Here is an excerpt from the current org.el included within Emacs Trunk (as of July 1, 2013): (defun org-sort (with-case) "Call `org-sort-entries', `org-table-sort-lines' or `org-sort-list'. Optional argument WITH-CASE means sort case-sensitively." (interactive "P") (cond ((org-at-table-p) (org-call-with-arg 'org-table-sort-lines with-case)) ((org-at-item-p) (org-call-with-arg 'org-sort-list with-case)) (t (org-call-with-arg 'org-sort-entries with-case)))) (defun org-sort-remove-invisible (s) (remove-text-properties 0 (length s) org-rm-props s) (while (string-match org-bracket-link-regexp s) (setq s (replace-match (if (match-end 2) (match-string 3 s) (match-string 1 s)) t t s))) s) (defvar org-priority-regexp) ; defined later in the file (defvar org-after-sorting-entries-or-items-hook nil "Hook that is run after a bunch of entries or items have been sorted. When children are sorted, the cursor is in the parent line when this hook gets called. When a region or a plain list is sorted, the cursor will be in the first entry of the sorted region/list.") (defun org-sort-entries (&optional with-case sorting-type getkey-func compare-func property) "Sort entries on a certain level of an outline tree. If there is an active region, the entries in the region are sorted. Else, if the cursor is before the first entry, sort the top-level items. Else, the children of the entry at point are sorted. Sorting can be alphabetically, numerically, by date/time as given by a time stamp, by a property or by priority. The command prompts for the sorting type unless it has been given to the function through the SORTING-TYPE argument, which needs to be a character, \(?n ?N ?a ?A ?t ?T ?s ?S ?d ?D ?p ?P ?o ?O ?r ?R ?f ?F). Here is the precise meaning of each character: n Numerically, by converting the beginning of the entry/item to a number. a Alphabetically, ignoring the TODO keyword and the priority, if any. o By order of TODO keywords. t By date/time, either the first active time stamp in the entry, or, if none exist, by the first inactive one. s By the scheduled date/time. d By deadline date/time. c By creation time, which is assumed to be the first inactive time stamp at the beginning of a line. p By priority according to the cookie. r By the value of a property. Capital letters will reverse the sort order. If the SORTING-TYPE is ?f or ?F, then GETKEY-FUNC specifies a function to be called with point at the beginning of the record. It must return either a string or a number that should serve as the sorting key for that record. Comparing entries ignores case by default. However, with an optional argument WITH-CASE, the sorting considers case as well." (interactive "P") (let ((case-func (if with-case 'identity 'downcase)) (cmstr ;; The clock marker is lost when using `sort-subr', let's ;; store the clocking string. (when (equal (marker-buffer org-clock-marker) (current-buffer)) (save-excursion (goto-char org-clock-marker) (looking-back "^.*") (match-string-no-properties 0)))) start beg end stars re re2 txt what tmp) ;; Find beginning and end of region to sort (cond ((org-region-active-p) ;; we will sort the region (setq end (region-end) what "region") (goto-char (region-beginning)) (if (not (org-at-heading-p)) (outline-next-heading)) (setq start (point))) ((or (org-at-heading-p) (condition-case nil (progn (org-back-to-heading) t) (error nil))) ;; we will sort the children of the current headline (org-back-to-heading) (setq start (point) end (progn (org-end-of-subtree t t) (or (bolp) (insert "\n")) (org-back-over-empty-lines) (point)) what "children") (goto-char start) (show-subtree) (outline-next-heading)) (t ;; we will sort the top-level entries in this file (goto-char (point-min)) (or (org-at-heading-p) (outline-next-heading)) (setq start (point)) (goto-char (point-max)) (beginning-of-line 1) (when (looking-at ".*?\\S-") ;; File ends in a non-white line (end-of-line 1) (insert "\n")) (setq end (point-max)) (setq what "top-level") (goto-char start) (show-all))) (setq beg (point)) (if (>= beg end) (error "Nothing to sort")) (looking-at "\$\\*+\$") (setq stars (match-string 1) re (concat "^" (regexp-quote stars) " +") re2 (concat "^" (regexp-quote (substring stars 0 -1)) "[ \t\n]") txt (buffer-substring beg end)) (if (not (equal (substring txt -1) "\n")) (setq txt (concat txt "\n"))) (if (and (not (equal stars "*")) (string-match re2 txt)) (error "Region to sort contains a level above the first entry")) (unless sorting-type (message "Sort %s: [a]lpha [n]umeric [p]riority p[r]operty todo[o]rder [f]unc [t]ime [s]cheduled [d]eadline [c]reated A/N/P/R/O/F/T/S/D/C means reversed:" what) (setq sorting-type (read-char-exclusive)) (and (= (downcase sorting-type) ?f) (setq getkey-func (org-icompleting-read "Sort using function: " obarray 'fboundp t nil nil)) (setq getkey-func (intern getkey-func))) (and (= (downcase sorting-type) ?r) (setq property (org-icompleting-read "Property: " (mapcar 'list (org-buffer-property-keys t)) nil t)))) (message "Sorting entries...") (save-restriction (narrow-to-region start end) (let ((dcst (downcase sorting-type)) (case-fold-search nil) (now (current-time))) (sort-subr (/= dcst sorting-type) ;; This function moves to the beginning character of the "record" to ;; be sorted. (lambda nil (if (re-search-forward re nil t) (goto-char (match-beginning 0)) (goto-char (point-max)))) ;; This function moves to the last character of the "record" being ;; sorted. (lambda nil (save-match-data (condition-case nil (outline-forward-same-level 1) (error (goto-char (point-max)))))) ;; This function returns the value that gets sorted against. (lambda nil (cond ((= dcst ?n) (if (looking-at org-complex-heading-regexp) (string-to-number (match-string 4)) nil)) ((= dcst ?a) (if (looking-at org-complex-heading-regexp) (funcall case-func (match-string 4)) nil)) ((= dcst ?t) (let ((end (save-excursion (outline-next-heading) (point)))) (if (or (re-search-forward org-ts-regexp end t) (re-search-forward org-ts-regexp-both end t)) (org-time-string-to-seconds (match-string 0)) (org-float-time now)))) ((= dcst ?c) (let ((end (save-excursion (outline-next-heading) (point)))) (if (re-search-forward (concat "^[ \t]*\\[" org-ts-regexp1 "\\]") end t) (org-time-string-to-seconds (match-string 0)) (org-float-time now)))) ((= dcst ?s) (let ((end (save-excursion (outline-next-heading) (point)))) (if (re-search-forward org-scheduled-time-regexp end t) (org-time-string-to-seconds (match-string 1)) (org-float-time now)))) ((= dcst ?d) (let ((end (save-excursion (outline-next-heading) (point)))) (if (re-search-forward org-deadline-time-regexp end t) (org-time-string-to-seconds (match-string 1)) (org-float-time now)))) ((= dcst ?p) (if (re-search-forward org-priority-regexp (point-at-eol) t) (string-to-char (match-string 2)) org-default-priority)) ((= dcst ?r) (or (org-entry-get nil property) "")) ((= dcst ?o) (if (looking-at org-complex-heading-regexp) (- 9999 (length (member (match-string 2) org-todo-keywords-1))))) ((= dcst ?f) (if getkey-func (progn (setq tmp (funcall getkey-func)) (if (stringp tmp) (setq tmp (funcall case-func tmp))) tmp) (error "Invalid key function `%s'" getkey-func))) (t (error "Invalid sorting type `%c'" sorting-type)))) nil (cond ((= dcst ?a) 'string<) ((= dcst ?f) compare-func) ((member dcst '(?p ?t ?s ?d ?c)) '<))))) (run-hooks 'org-after-sorting-entries-or-items-hook) ;; Reset the clock marker if needed (when cmstr (save-excursion (goto-char start) (search-forward cmstr nil t) (move-marker org-clock-marker (point)))) (message "Sorting entries...done"))) (defun org-do-sort (table what &optional with-case sorting-type) "Sort TABLE of WHAT according to SORTING-TYPE. The user will be prompted for the SORTING-TYPE if the call to this function does not specify it. WHAT is only for the prompt, to indicate what is being sorted. The sorting key will be extracted from the car of the elements of the table. If WITH-CASE is non-nil, the sorting will be case-sensitive." (unless sorting-type (message "Sort %s: [a]lphabetic, [n]umeric, [t]ime. A/N/T means reversed:" what) (setq sorting-type (read-char-exclusive))) (let ((dcst (downcase sorting-type)) extractfun comparefun) ;; Define the appropriate functions (cond ((= dcst ?n) (setq extractfun 'string-to-number comparefun (if (= dcst sorting-type) '< '>))) ((= dcst ?a) (setq extractfun (if with-case (lambda(x) (org-sort-remove-invisible x)) (lambda(x) (downcase (org-sort-remove-invisible x)))) comparefun (if (= dcst sorting-type) 'string< (lambda (a b) (and (not (string< a b)) (not (string= a b))))))) ((= dcst ?t) (setq extractfun (lambda (x) (if (or (string-match org-ts-regexp x) (string-match org-ts-regexp-both x)) (org-float-time (org-time-string-to-time (match-string 0 x))) 0)) comparefun (if (= dcst sorting-type) '< '>))) (t (error "Invalid sorting type `%c'" sorting-type))) (sort (mapcar (lambda (x) (cons (funcall extractfun (car x)) (cdr x))) table) (lambda (a b) (funcall comparefun (car a) (car b))))))

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Node.js Adventure - When Node Flying in Wind

- by Shaun

In the first post of this series I mentioned some popular modules in the community, such as underscore, async, etc.. I also listed a module named “Wind (zh-CN)”, which is created by one of my friend, Jeff Zhao (zh-CN). Now I would like to use a separated post to introduce this module since I feel it brings a new async programming style in not only Node.js but JavaScript world. If you know or heard about the new feature in C# 5.0 called “async and await”, or you learnt F#, you will find the “Wind” brings the similar async programming experience in JavaScript. By using “Wind”, we can write async code that looks like the sync code. The callbacks, async stats and exceptions will be handled by “Wind” automatically and transparently. What’s the Problem: Dense “Callback” Phobia Let’s firstly back to my second post in this series. As I mentioned in that post, when we wanted to read some records from SQL Server we need to open the database connection, and then execute the query. In Node.js all IO operation are designed as async callback pattern which means when the operation was done, it will invoke a function which was taken from the last parameter. For example the database connection opening code would be like this. 1: sql.open(connectionString, function(error, conn) { 2: if(error) { 3: // some error handling code 4: } 5: else { 6: // connection opened successfully 7: } 8: }); And then if we need to query the database the code would be like this. It nested in the previous function. 1: sql.open(connectionString, function(error, conn) { 2: if(error) { 3: // some error handling code 4: } 5: else { 6: // connection opened successfully 7: conn.queryRaw(command, function(error, results) { 8: if(error) { 9: // failed to execute this command 10: } 11: else { 12: // records retrieved successfully 13: } 14: }; 15: } 16: }); Assuming if we need to copy some data from this database to another then we need to open another connection and execute the command within the function under the query function. 1: sql.open(connectionString, function(error, conn) { 2: if(error) { 3: // some error handling code 4: } 5: else { 6: // connection opened successfully 7: conn.queryRaw(command, function(error, results) { 8: if(error) { 9: // failed to execute this command 10: } 11: else { 12: // records retrieved successfully 13: target.open(targetConnectionString, function(error, t_conn) { 14: if(error) { 15: // connect failed 16: } 17: else { 18: t_conn.queryRaw(copy_command, function(error, results) { 19: if(error) { 20: // copy failed 21: } 22: else { 23: // and then, what do you want to do now... 24: } 25: }; 26: } 27: }; 28: } 29: }; 30: } 31: }); This is just an example. In the real project the logic would be more complicated. This means our application might be messed up and the business process will be fragged by many callback functions. I would like call this “Dense Callback Phobia”. This might be a challenge how to make code straightforward and easy to read, something like below. 1: try 2: { 3: // open source connection 4: var s_conn = sqlConnect(s_connectionString); 5: // retrieve data 6: var results = sqlExecuteCommand(s_conn, s_command); 7: 8: // open target connection 9: var t_conn = sqlConnect(t_connectionString); 10: // prepare the copy command 11: var t_command = getCopyCommand(results); 12: // execute the copy command 13: sqlExecuteCommand(s_conn, t_command); 14: } 15: catch (ex) 16: { 17: // error handling 18: } What’s the Problem: Sync-styled Async Programming Similar as the previous problem, the callback-styled async programming model makes the upcoming operation as a part of the current operation, and mixed with the error handling code. So it’s very hard to understand what on earth this code will do. And since Node.js utilizes non-blocking IO mode, we cannot invoke those operations one by one, as they will be executed concurrently. For example, in this post when I tried to copy the records from Windows Azure SQL Database (a.k.a. WASD) to Windows Azure Table Storage, if I just insert the data into table storage one by one and then print the “Finished” message, I will see the message shown before the data had been copied. This is because all operations were executed at the same time. In order to make the copy operation and print operation executed synchronously I introduced a module named “async” and the code was changed as below. 1: async.forEach(results.rows, 2: function (row, callback) { 3: var resource = { 4: "PartitionKey": row[1], 5: "RowKey": row[0], 6: "Value": row[2] 7: }; 8: client.insertEntity(tableName, resource, function (error) { 9: if (error) { 10: callback(error); 11: } 12: else { 13: console.log("entity inserted."); 14: callback(null); 15: } 16: }); 17: }, 18: function (error) { 19: if (error) { 20: error["target"] = "insertEntity"; 21: res.send(500, error); 22: } 23: else { 24: console.log("all done."); 25: res.send(200, "Done!"); 26: } 27: }); It ensured that the “Finished” message will be printed when all table entities had been inserted. But it cannot promise that the records will be inserted in sequence. It might be another challenge to make the code looks like in sync-style? 1: try 2: { 3: forEach(row in rows) { 4: var entity = { /* ... */ }; 5: tableClient.insert(tableName, entity); 6: } 7: 8: console.log("Finished"); 9: } 10: catch (ex) { 11: console.log(ex); 12: } How “Wind” Helps “Wind” is a JavaScript library which provides the control flow with plain JavaScript for asynchronous programming (and more) without additional pre-compiling steps. It’s available in NPM so that we can install it through “npm install wind”. Now let’s create a very simple Node.js application as the example. This application will take some website URLs from the command arguments and tried to retrieve the body length and print them in console. Then at the end print “Finish”. I’m going to use “request” module to make the HTTP call simple so I also need to install by the command “npm install request”. The code would be like this. 1: var request = require("request"); 2: 3: // get the urls from arguments, the first two arguments are `node.exe` and `fetch.js` 4: var args = process.argv.splice(2); 5: 6: // main function 7: var main = function() { 8: for(var i = 0; i < args.length; i++) { 9: // get the url 10: var url = args[i]; 11: // send the http request and try to get the response and body 12: request(url, function(error, response, body) { 13: if(!error && response.statusCode == 200) { 14: // log the url and the body length 15: console.log( 16: "%s: %d.", 17: response.request.uri.href, 18: body.length); 19: } 20: else { 21: // log error 22: console.log(error); 23: } 24: }); 25: } 26: 27: // finished 28: console.log("Finished"); 29: }; 30: 31: // execute the main function 32: main(); Let’s execute this application. (I made them in multi-lines for better reading.) 1: node fetch.js 2: "http://www.igt.com/us-en.aspx" 3: "http://www.igt.com/us-en/games.aspx" 4: "http://www.igt.com/us-en/cabinets.aspx" 5: "http://www.igt.com/us-en/systems.aspx" 6: "http://www.igt.com/us-en/interactive.aspx" 7: "http://www.igt.com/us-en/social-gaming.aspx" 8: "http://www.igt.com/support.aspx" Below is the output. As you can see the finish message was printed at the beginning, and the pages’ length retrieved in a different order than we specified. This is because in this code the request command, console logging command are executed asynchronously and concurrently. Now let’s introduce “Wind” to make them executed in order, which means it will request the websites one by one, and print the message at the end. First of all we need to import the “Wind” package and make sure the there’s only one global variant named “Wind”, and ensure it’s “Wind” instead of “wind”. 1: var Wind = require("wind"); Next, we need to tell “Wind” which code will be executed asynchronously so that “Wind” can control the execution process. In this case the “request” operation executed asynchronously so we will create a “Task” by using a build-in helps function in “Wind” named Wind.Async.Task.create. 1: var requestBodyLengthAsync = function(url) { 2: return Wind.Async.Task.create(function(t) { 3: request(url, function(error, response, body) { 4: if(error || response.statusCode != 200) { 5: t.complete("failure", error); 6: } 7: else { 8: var data = 9: { 10: uri: response.request.uri.href, 11: length: body.length 12: }; 13: t.complete("success", data); 14: } 15: }); 16: }); 17: }; The code above created a “Task” from the original request calling code. In “Wind” a “Task” means an operation will be finished in some time in the future. A “Task” can be started by invoke its start() method, but no one knows when it actually will be finished. The Wind.Async.Task.create helped us to create a task. The only parameter is a function where we can put the actual operation in, and then notify the task object it’s finished successfully or failed by using the complete() method. In the code above I invoked the request method. If it retrieved the response successfully I set the status of this task as “success” with the URL and body length. If it failed I set this task as “failure” and pass the error out. Next, we will change the main() function. In “Wind” if we want a function can be controlled by Wind we need to mark it as “async”. This should be done by using the code below. 1: var main = eval(Wind.compile("async", function() { 2: })); When the application is running, Wind will detect “eval(Wind.compile(“async”, function” and generate an anonymous code from the body of this original function. Then the application will run the anonymous code instead of the original one. In our example the main function will be like this. 1: var main = eval(Wind.compile("async", function() { 2: for(var i = 0; i < args.length; i++) { 3: try 4: { 5: var result = $await(requestBodyLengthAsync(args[i])); 6: console.log( 7: "%s: %d.", 8: result.uri, 9: result.length); 10: } 11: catch (ex) { 12: console.log(ex); 13: } 14: } 15: 16: console.log("Finished"); 17: })); As you can see, when I tried to request the URL I use a new command named “$await”. It tells Wind, the operation next to $await will be executed asynchronously, and the main thread should be paused until it finished (or failed). So in this case, my application will be pause when the first response was received, and then print its body length, then try the next one. At the end, print the finish message. Finally, execute the main function. The full code would be like this. 1: var request = require("request"); 2: var Wind = require("wind"); 3: 4: var args = process.argv.splice(2); 5: 6: var requestBodyLengthAsync = function(url) { 7: return Wind.Async.Task.create(function(t) { 8: request(url, function(error, response, body) { 9: if(error || response.statusCode != 200) { 10: t.complete("failure", error); 11: } 12: else { 13: var data = 14: { 15: uri: response.request.uri.href, 16: length: body.length 17: }; 18: t.complete("success", data); 19: } 20: }); 21: }); 22: }; 23: 24: var main = eval(Wind.compile("async", function() { 25: for(var i = 0; i < args.length; i++) { 26: try 27: { 28: var result = $await(requestBodyLengthAsync(args[i])); 29: console.log( 30: "%s: %d.", 31: result.uri, 32: result.length); 33: } 34: catch (ex) { 35: console.log(ex); 36: } 37: } 38: 39: console.log("Finished"); 40: })); 41: 42: main().start(); Run our new application. At the beginning we will see the compiled and generated code by Wind. Then we can see the pages were requested one by one, and at the end the finish message was printed. Below is the code Wind generated for us. As you can see the original code, the output code were shown. 1: // Original: 2: function () { 3: for(var i = 0; i < args.length; i++) { 4: try 5: { 6: var result = $await(requestBodyLengthAsync(args[i])); 7: console.log( 8: "%s: %d.", 9: result.uri, 10: result.length); 11: } 12: catch (ex) { 13: console.log(ex); 14: } 15: } 16: 17: console.log("Finished"); 18: } 19: 20: // Compiled: 21: /* async << function () { */ (function () { 22: var _builder_$0 = Wind.builders["async"]; 23: return _builder_$0.Start(this, 24: _builder_$0.Combine( 25: _builder_$0.Delay(function () { 26: /* var i = 0; */ var i = 0; 27: /* for ( */ return _builder_$0.For(function () { 28: /* ; i < args.length */ return i < args.length; 29: }, function () { 30: /* ; i ++) { */ i ++; 31: }, 32: /* try { */ _builder_$0.Try( 33: _builder_$0.Delay(function () { 34: /* var result = $await(requestBodyLengthAsync(args[i])); */ return _builder_$0.Bind(requestBodyLengthAsync(args[i]), function (result) { 35: /* console.log("%s: %d.", result.uri, result.length); */ console.log("%s: %d.", result.uri, result.length); 36: return _builder_$0.Normal(); 37: }); 38: }), 39: /* } catch (ex) { */ function (ex) { 40: /* console.log(ex); */ console.log(ex); 41: return _builder_$0.Normal(); 42: /* } */ }, 43: null 44: ) 45: /* } */ ); 46: }), 47: _builder_$0.Delay(function () { 48: /* console.log("Finished"); */ console.log("Finished"); 49: return _builder_$0.Normal(); 50: }) 51: ) 52: ); 53: /* } */ }) How Wind Works Someone may raise a big concern when you find I utilized “eval” in my code. Someone may assume that Wind utilizes “eval” to execute some code dynamically while “eval” is very low performance. But I would say, Wind does NOT use “eval” to run the code. It only use “eval” as a flag to know which code should be compiled at runtime. When the code was firstly been executed, Wind will check and find “eval(Wind.compile(“async”, function”. So that it knows this function should be compiled. Then it utilized parse-js to analyze the inner JavaScript and generated the anonymous code in memory. Then it rewrite the original code so that when the application was running it will use the anonymous one instead of the original one. Since the code generation was done at the beginning of the application was started, in the future no matter how long our application runs and how many times the async function was invoked, it will use the generated code, no need to generate again. So there’s no significant performance hurt when using Wind. Wind in My Previous Demo Let’s adopt Wind into one of my previous demonstration and to see how it helps us to make our code simple, straightforward and easy to read and understand. In this post when I implemented the functionality that copied the records from my WASD to table storage, the logic would be like this. 1, Open database connection. 2, Execute a query to select all records from the table. 3, Recreate the table in Windows Azure table storage. 4, Create entities from each of the records retrieved previously, and then insert them into table storage. 5, Finally, show message as the HTTP response. But as the image below, since there are so many callbacks and async operations, it’s very hard to understand my logic from the code. Now let’s use Wind to rewrite our code. First of all, of course, we need the Wind package. Then we need to include the package files into project and mark them as “Copy always”. Add the Wind package into the source code. Pay attention to the variant name, you must use “Wind” instead of “wind”. 1: var express = require("express"); 2: var async = require("async"); 3: var sql = require("node-sqlserver"); 4: var azure = require("azure"); 5: var Wind = require("wind"); Now we need to create some async functions by using Wind. All async functions should be wrapped so that it can be controlled by Wind which are open database, retrieve records, recreate table (delete and create) and insert entity in table. Below are these new functions. All of them are created by using Wind.Async.Task.create. 1: sql.openAsync = function (connectionString) { 2: return Wind.Async.Task.create(function (t) { 3: sql.open(connectionString, function (error, conn) { 4: if (error) { 5: t.complete("failure", error); 6: } 7: else { 8: t.complete("success", conn); 9: } 10: }); 11: }); 12: }; 13: 14: sql.queryAsync = function (conn, query) { 15: return Wind.Async.Task.create(function (t) { 16: conn.queryRaw(query, function (error, results) { 17: if (error) { 18: t.complete("failure", error); 19: } 20: else { 21: t.complete("success", results); 22: } 23: }); 24: }); 25: }; 26: 27: azure.recreateTableAsync = function (tableName) { 28: return Wind.Async.Task.create(function (t) { 29: client.deleteTable(tableName, function (error, successful, response) { 30: console.log("delete table finished"); 31: client.createTableIfNotExists(tableName, function (error, successful, response) { 32: console.log("create table finished"); 33: if (error) { 34: t.complete("failure", error); 35: } 36: else { 37: t.complete("success", null); 38: } 39: }); 40: }); 41: }); 42: }; 43: 44: azure.insertEntityAsync = function (tableName, entity) { 45: return Wind.Async.Task.create(function (t) { 46: client.insertEntity(tableName, entity, function (error, entity, response) { 47: if (error) { 48: t.complete("failure", error); 49: } 50: else { 51: t.complete("success", null); 52: } 53: }); 54: }); 55: }; Then in order to use these functions we will create a new function which contains all steps for data copying. 1: var copyRecords = eval(Wind.compile("async", function (req, res) { 2: try { 3: } 4: catch (ex) { 5: console.log(ex); 6: res.send(500, "Internal error."); 7: } 8: })); Let’s execute steps one by one with the “$await” keyword introduced by Wind so that it will be invoked in sequence. First is to open the database connection. 1: var copyRecords = eval(Wind.compile("async", function (req, res) { 2: try { 3: // connect to the windows azure sql database 4: var conn = $await(sql.openAsync(connectionString)); 5: console.log("connection opened"); 6: } 7: catch (ex) { 8: console.log(ex); 9: res.send(500, "Internal error."); 10: } 11: })); Then retrieve all records from the database connection. 1: var copyRecords = eval(Wind.compile("async", function (req, res) { 2: try { 3: // connect to the windows azure sql database 4: var conn = $await(sql.openAsync(connectionString)); 5: console.log("connection opened"); 6: // retrieve all records from database 7: var results = $await(sql.queryAsync(conn, "SELECT * FROM [Resource]")); 8: console.log("records selected. count = %d", results.rows.length); 9: } 10: catch (ex) { 11: console.log(ex); 12: res.send(500, "Internal error."); 13: } 14: })); After recreated the table, we need to create the entities and insert them into table storage. 1: var copyRecords = eval(Wind.compile("async", function (req, res) { 2: try { 3: // connect to the windows azure sql database 4: var conn = $await(sql.openAsync(connectionString)); 5: console.log("connection opened"); 6: // retrieve all records from database 7: var results = $await(sql.queryAsync(conn, "SELECT * FROM [Resource]")); 8: console.log("records selected. count = %d", results.rows.length); 9: if (results.rows.length > 0) { 10: // recreate the table 11: $await(azure.recreateTableAsync(tableName)); 12: console.log("table created"); 13: // insert records in table storage one by one 14: for (var i = 0; i < results.rows.length; i++) { 15: var entity = { 16: "PartitionKey": results.rows[i][1], 17: "RowKey": results.rows[i][0], 18: "Value": results.rows[i][2] 19: }; 20: $await(azure.insertEntityAsync(tableName, entity)); 21: console.log("entity inserted"); 22: } 23: } 24: } 25: catch (ex) { 26: console.log(ex); 27: res.send(500, "Internal error."); 28: } 29: })); Finally, send response back to the browser. 1: var copyRecords = eval(Wind.compile("async", function (req, res) { 2: try { 3: // connect to the windows azure sql database 4: var conn = $await(sql.openAsync(connectionString)); 5: console.log("connection opened"); 6: // retrieve all records from database 7: var results = $await(sql.queryAsync(conn, "SELECT * FROM [Resource]")); 8: console.log("records selected. count = %d", results.rows.length); 9: if (results.rows.length > 0) { 10: // recreate the table 11: $await(azure.recreateTableAsync(tableName)); 12: console.log("table created"); 13: // insert records in table storage one by one 14: for (var i = 0; i < results.rows.length; i++) { 15: var entity = { 16: "PartitionKey": results.rows[i][1], 17: "RowKey": results.rows[i][0], 18: "Value": results.rows[i][2] 19: }; 20: $await(azure.insertEntityAsync(tableName, entity)); 21: console.log("entity inserted"); 22: } 23: // send response 24: console.log("all done"); 25: res.send(200, "All done!"); 26: } 27: } 28: catch (ex) { 29: console.log(ex); 30: res.send(500, "Internal error."); 31: } 32: })); If we compared with the previous code we will find now it became more readable and much easy to understand. It’s very easy to know what this function does even though without any comments. When user go to URL “/was/copyRecords” we will execute the function above. The code would be like this. 1: app.get("/was/copyRecords", function (req, res) { 2: copyRecords(req, res).start(); 3: }); And below is the logs printed in local compute emulator console. As we can see the functions executed one by one and then finally the response back to me browser. Scaffold Functions in Wind Wind provides not only the async flow control and compile functions, but many scaffold methods as well. We can build our async code more easily by using them. I’m going to introduce some basic scaffold functions here. In the code above I created some functions which wrapped from the original async function such as open database, create table, etc.. All of them are very similar, created a task by using Wind.Async.Task.create, return error or result object through Task.complete function. In fact, Wind provides some functions for us to create task object from the original async functions. If the original async function only has a callback parameter, we can use Wind.Async.Binding.fromCallback method to get the task object directly. For example the code below returned the task object which wrapped the file exist check function. 1: var Wind = require("wind"); 2: var fs = require("fs"); 3: 4: fs.existsAsync = Wind.Async.Binding.fromCallback(fs.exists); In Node.js a very popular async function pattern is that, the first parameter in the callback function represent the error object, and the other parameters is the return values. In this case we can use another build-in function in Wind named Wind.Async.Binding.fromStandard. For example, the open database function can be created from the code below. 1: sql.openAsync = Wind.Async.Binding.fromStandard(sql.open); 2: 3: /* 4: sql.openAsync = function (connectionString) { 5: return Wind.Async.Task.create(function (t) { 6: sql.open(connectionString, function (error, conn) { 7: if (error) { 8: t.complete("failure", error); 9: } 10: else { 11: t.complete("success", conn); 12: } 13: }); 14: }); 15: }; 16: */ When I was testing the scaffold functions under Wind.Async.Binding I found for some functions, such as the Azure SDK insert entity function, cannot be processed correctly. So I personally suggest writing the wrapped method manually. Another scaffold method in Wind is the parallel tasks coordination. In this example, the steps of open database, retrieve records and recreated table should be invoked one by one, but it can be executed in parallel when copying data from database to table storage. In Wind there’s a scaffold function named Task.whenAll which can be used here. Task.whenAll accepts a list of tasks and creates a new task. It will be returned only when all tasks had been completed, or any errors occurred. For example in the code below I used the Task.whenAll to make all copy operation executed at the same time. 1: var copyRecordsInParallel = eval(Wind.compile("async", function (req, res) { 2: try { 3: // connect to the windows azure sql database 4: var conn = $await(sql.openAsync(connectionString)); 5: console.log("connection opened"); 6: // retrieve all records from database 7: var results = $await(sql.queryAsync(conn, "SELECT * FROM [Resource]")); 8: console.log("records selected. count = %d", results.rows.length); 9: if (results.rows.length > 0) { 10: // recreate the table 11: $await(azure.recreateTableAsync(tableName)); 12: console.log("table created"); 13: // insert records in table storage in parallal 14: var tasks = new Array(results.rows.length); 15: for (var i = 0; i < results.rows.length; i++) { 16: var entity = { 17: "PartitionKey": results.rows[i][1], 18: "RowKey": results.rows[i][0], 19: "Value": results.rows[i][2] 20: }; 21: tasks[i] = azure.insertEntityAsync(tableName, entity); 22: } 23: $await(Wind.Async.Task.whenAll(tasks)); 24: // send response 25: console.log("all done"); 26: res.send(200, "All done!"); 27: } 28: } 29: catch (ex) { 30: console.log(ex); 31: res.send(500, "Internal error."); 32: } 33: })); 34: 35: app.get("/was/copyRecordsInParallel", function (req, res) { 36: copyRecordsInParallel(req, res).start(); 37: }); Besides the task creation and coordination, Wind supports the cancellation solution so that we can send the cancellation signal to the tasks. It also includes exception solution which means any exceptions will be reported to the caller function. Summary In this post I introduced a Node.js module named Wind, which created by my friend Jeff Zhao. As you can see, different from other async library and framework, adopted the idea from F# and C#, Wind utilizes runtime code generation technology to make it more easily to write async, callback-based functions in a sync-style way. By using Wind there will be almost no callback, and the code will be very easy to understand. Currently Wind is still under developed and improved. There might be some problems but the author, Jeff, should be very happy and enthusiastic to learn your problems, feedback, suggestion and comments. You can contact Jeff by - Email: [email protected] - Group: https://groups.google.com/d/forum/windjs - GitHub: https://github.com/JeffreyZhao/wind/issues Source code can be download here. Hope this helps, Shaun All documents and related graphics, codes are provided "AS IS" without warranty of any kind. Copyright © Shaun Ziyan Xu. This work is licensed under the Creative Commons License.

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How LINQ to Object statements work

- by rajbk

This post goes into detail as to now LINQ statements work when querying a collection of objects. This topic assumes you have an understanding of how generics, delegates, implicitly typed variables, lambda expressions, object/collection initializers, extension methods and the yield statement work. I would also recommend you read my previous two posts: Using Delegates in C# Part 1 Using Delegates in C# Part 2 We will start by writing some methods to filter a collection of data. Assume we have an Employee class like so: 1: public class Employee { 2: public int ID { get; set;} 3: public string FirstName { get; set;} 4: public string LastName {get; set;} 5: public string Country { get; set; } 6: } and a collection of employees like so: 1: var employees = new List<Employee> { 2: new Employee { ID = 1, FirstName = "John", LastName = "Wright", Country = "USA" }, 3: new Employee { ID = 2, FirstName = "Jim", LastName = "Ashlock", Country = "UK" }, 4: new Employee { ID = 3, FirstName = "Jane", LastName = "Jackson", Country = "CHE" }, 5: new Employee { ID = 4, FirstName = "Jill", LastName = "Anderson", Country = "AUS" }, 6: }; Filtering We wish to find all employees that have an even ID. We could start off by writing a method that takes in a list of employees and returns a filtered list of employees with an even ID. 1: static List<Employee> GetEmployeesWithEvenID(List<Employee> employees) { 2: var filteredEmployees = new List<Employee>(); 3: foreach (Employee emp in employees) { 4: if (emp.ID % 2 == 0) { 5: filteredEmployees.Add(emp); 6: } 7: } 8: return filteredEmployees; 9: } The method can be rewritten to return an IEnumerable<Employee> using the yield return keyword. 1: static IEnumerable<Employee> GetEmployeesWithEvenID(IEnumerable<Employee> employees) { 2: foreach (Employee emp in employees) { 3: if (emp.ID % 2 == 0) { 4: yield return emp; 5: } 6: } 7: } We put these together in a console application. 1: using System; 2: using System.Collections.Generic; 3: //No System.Linq 4: 5: public class Program 6: { 7: [STAThread] 8: static void Main(string[] args) 9: { 10: var employees = new List<Employee> { 11: new Employee { ID = 1, FirstName = "John", LastName = "Wright", Country = "USA" }, 12: new Employee { ID = 2, FirstName = "Jim", LastName = "Ashlock", Country = "UK" }, 13: new Employee { ID = 3, FirstName = "Jane", LastName = "Jackson", Country = "CHE" }, 14: new Employee { ID = 4, FirstName = "Jill", LastName = "Anderson", Country = "AUS" }, 15: }; 16: var filteredEmployees = GetEmployeesWithEvenID(employees); 17: 18: foreach (Employee emp in filteredEmployees) { 19: Console.WriteLine("ID {0} First_Name {1} Last_Name {2} Country {3}", 20: emp.ID, emp.FirstName, emp.LastName, emp.Country); 21: } 22: 23: Console.ReadLine(); 24: } 25: 26: static IEnumerable<Employee> GetEmployeesWithEvenID(IEnumerable<Employee> employees) { 27: foreach (Employee emp in employees) { 28: if (emp.ID % 2 == 0) { 29: yield return emp; 30: } 31: } 32: } 33: } 34: 35: public class Employee { 36: public int ID { get; set;} 37: public string FirstName { get; set;} 38: public string LastName {get; set;} 39: public string Country { get; set; } 40: } Output: ID 2 First_Name Jim Last_Name Ashlock Country UK ID 4 First_Name Jill Last_Name Anderson Country AUS Our filtering method is too specific. Let us change it so that it is capable of doing different types of filtering and lets give our method the name Where ;-) We will add another parameter to our Where method. This additional parameter will be a delegate with the following declaration. public delegate bool Filter(Employee emp); The idea is that the delegate parameter in our Where method will point to a method that contains the logic to do our filtering thereby freeing our Where method from any dependency. The method is shown below: 1: static IEnumerable<Employee> Where(IEnumerable<Employee> employees, Filter filter) { 2: foreach (Employee emp in employees) { 3: if (filter(emp)) { 4: yield return emp; 5: } 6: } 7: } Making the change to our app, we create a new instance of the Filter delegate on line 14 with a target set to the method EmployeeHasEvenId. Running the code will produce the same output. 1: public delegate bool Filter(Employee emp); 2: 3: public class Program 4: { 5: [STAThread] 6: static void Main(string[] args) 7: { 8: var employees = new List<Employee> { 9: new Employee { ID = 1, FirstName = "John", LastName = "Wright", Country = "USA" }, 10: new Employee { ID = 2, FirstName = "Jim", LastName = "Ashlock", Country = "UK" }, 11: new Employee { ID = 3, FirstName = "Jane", LastName = "Jackson", Country = "CHE" }, 12: new Employee { ID = 4, FirstName = "Jill", LastName = "Anderson", Country = "AUS" } 13: }; 14: var filterDelegate = new Filter(EmployeeHasEvenId); 15: var filteredEmployees = Where(employees, filterDelegate); 16: 17: foreach (Employee emp in filteredEmployees) { 18: Console.WriteLine("ID {0} First_Name {1} Last_Name {2} Country {3}", 19: emp.ID, emp.FirstName, emp.LastName, emp.Country); 20: } 21: Console.ReadLine(); 22: } 23: 24: static bool EmployeeHasEvenId(Employee emp) { 25: return emp.ID % 2 == 0; 26: } 27: 28: static IEnumerable<Employee> Where(IEnumerable<Employee> employees, Filter filter) { 29: foreach (Employee emp in employees) { 30: if (filter(emp)) { 31: yield return emp; 32: } 33: } 34: } 35: } 36: 37: public class Employee { 38: public int ID { get; set;} 39: public string FirstName { get; set;} 40: public string LastName {get; set;} 41: public string Country { get; set; } 42: } Lets use lambda expressions to inline the contents of the EmployeeHasEvenId method in place of the method. The next code snippet shows this change (see line 15). For brevity, the Employee class declaration has been skipped. 1: public delegate bool Filter(Employee emp); 2: 3: public class Program 4: { 5: [STAThread] 6: static void Main(string[] args) 7: { 8: var employees = new List<Employee> { 9: new Employee { ID = 1, FirstName = "John", LastName = "Wright", Country = "USA" }, 10: new Employee { ID = 2, FirstName = "Jim", LastName = "Ashlock", Country = "UK" }, 11: new Employee { ID = 3, FirstName = "Jane", LastName = "Jackson", Country = "CHE" }, 12: new Employee { ID = 4, FirstName = "Jill", LastName = "Anderson", Country = "AUS" } 13: }; 14: var filterDelegate = new Filter(EmployeeHasEvenId); 15: var filteredEmployees = Where(employees, emp => emp.ID % 2 == 0); 16: 17: foreach (Employee emp in filteredEmployees) { 18: Console.WriteLine("ID {0} First_Name {1} Last_Name {2} Country {3}", 19: emp.ID, emp.FirstName, emp.LastName, emp.Country); 20: } 21: Console.ReadLine(); 22: } 23: 24: static bool EmployeeHasEvenId(Employee emp) { 25: return emp.ID % 2 == 0; 26: } 27: 28: static IEnumerable<Employee> Where(IEnumerable<Employee> employees, Filter filter) { 29: foreach (Employee emp in employees) { 30: if (filter(emp)) { 31: yield return emp; 32: } 33: } 34: } 35: } 36: The output displays the same two employees. Our Where method is too restricted since it works with a collection of Employees only. Lets change it so that it works with any IEnumerable<T>. In addition, you may recall from my previous post, that .NET 3.5 comes with a lot of predefined delegates including public delegate TResult Func<T, TResult>(T arg); We will get rid of our Filter delegate and use the one above instead. We apply these two changes to our code. 1: public class Program 2: { 3: [STAThread] 4: static void Main(string[] args) 5: { 6: var employees = new List<Employee> { 7: new Employee { ID = 1, FirstName = "John", LastName = "Wright", Country = "USA" }, 8: new Employee { ID = 2, FirstName = "Jim", LastName = "Ashlock", Country = "UK" }, 9: new Employee { ID = 3, FirstName = "Jane", LastName = "Jackson", Country = "CHE" }, 10: new Employee { ID = 4, FirstName = "Jill", LastName = "Anderson", Country = "AUS" } 11: }; 12: 13: var filteredEmployees = Where(employees, emp => emp.ID % 2 == 0); 14: 15: foreach (Employee emp in filteredEmployees) { 16: Console.WriteLine("ID {0} First_Name {1} Last_Name {2} Country {3}", 17: emp.ID, emp.FirstName, emp.LastName, emp.Country); 18: } 19: Console.ReadLine(); 20: } 21: 22: static IEnumerable<T> Where<T>(IEnumerable<T> source, Func<T, bool> filter) { 23: foreach (var x in source) { 24: if (filter(x)) { 25: yield return x; 26: } 27: } 28: } 29: } We have successfully implemented a way to filter any IEnumerable<T> based on a filter criteria. Projection Now lets enumerate on the items in the IEnumerable<Employee> we got from the Where method and copy them into a new IEnumerable<EmployeeFormatted>. The EmployeeFormatted class will only have a FullName and ID property. 1: public class EmployeeFormatted { 2: public int ID { get; set; } 3: public string FullName {get; set;} 4: } We could “project” our existing IEnumerable<Employee> into a new collection of IEnumerable<EmployeeFormatted> with the help of a new method. We will call this method Select ;-) 1: static IEnumerable<EmployeeFormatted> Select(IEnumerable<Employee> employees) { 2: foreach (var emp in employees) { 3: yield return new EmployeeFormatted { 4: ID = emp.ID, 5: FullName = emp.LastName + ", " + emp.FirstName 6: }; 7: } 8: } The changes are applied to our app. 1: public class Program 2: { 3: [STAThread] 4: static void Main(string[] args) 5: { 6: var employees = new List<Employee> { 7: new Employee { ID = 1, FirstName = "John", LastName = "Wright", Country = "USA" }, 8: new Employee { ID = 2, FirstName = "Jim", LastName = "Ashlock", Country = "UK" }, 9: new Employee { ID = 3, FirstName = "Jane", LastName = "Jackson", Country = "CHE" }, 10: new Employee { ID = 4, FirstName = "Jill", LastName = "Anderson", Country = "AUS" } 11: }; 12: 13: var filteredEmployees = Where(employees, emp => emp.ID % 2 == 0); 14: var formattedEmployees = Select(filteredEmployees); 15: 16: foreach (EmployeeFormatted emp in formattedEmployees) { 17: Console.WriteLine("ID {0} Full_Name {1}", 18: emp.ID, emp.FullName); 19: } 20: Console.ReadLine(); 21: } 22: 23: static IEnumerable<T> Where<T>(IEnumerable<T> source, Func<T, bool> filter) { 24: foreach (var x in source) { 25: if (filter(x)) { 26: yield return x; 27: } 28: } 29: } 30: 31: static IEnumerable<EmployeeFormatted> Select(IEnumerable<Employee> employees) { 32: foreach (var emp in employees) { 33: yield return new EmployeeFormatted { 34: ID = emp.ID, 35: FullName = emp.LastName + ", " + emp.FirstName 36: }; 37: } 38: } 39: } 40: 41: public class Employee { 42: public int ID { get; set;} 43: public string FirstName { get; set;} 44: public string LastName {get; set;} 45: public string Country { get; set; } 46: } 47: 48: public class EmployeeFormatted { 49: public int ID { get; set; } 50: public string FullName {get; set;} 51: } Output: ID 2 Full_Name Ashlock, Jim ID 4 Full_Name Anderson, Jill We have successfully selected employees who have an even ID and then shaped our data with the help of the Select method so that the final result is an IEnumerable<EmployeeFormatted>. Lets make our Select method more generic so that the user is given the freedom to shape what the output would look like. We can do this, like before, with lambda expressions. Our Select method is changed to accept a delegate as shown below. TSource will be the type of data that comes in and TResult will be the type the user chooses (shape of data) as returned from the selector delegate. 1: 2: static IEnumerable<TResult> Select<TSource, TResult>(IEnumerable<TSource> source, Func<TSource, TResult> selector) { 3: foreach (var x in source) { 4: yield return selector(x); 5: } 6: } We see the new changes to our app. On line 15, we use lambda expression to specify the shape of the data. In this case the shape will be of type EmployeeFormatted. 1: 2: public class Program 3: { 4: [STAThread] 5: static void Main(string[] args) 6: { 7: var employees = new List<Employee> { 8: new Employee { ID = 1, FirstName = "John", LastName = "Wright", Country = "USA" }, 9: new Employee { ID = 2, FirstName = "Jim", LastName = "Ashlock", Country = "UK" }, 10: new Employee { ID = 3, FirstName = "Jane", LastName = "Jackson", Country = "CHE" }, 11: new Employee { ID = 4, FirstName = "Jill", LastName = "Anderson", Country = "AUS" } 12: }; 13: 14: var filteredEmployees = Where(employees, emp => emp.ID % 2 == 0); 15: var formattedEmployees = Select(filteredEmployees, (emp) => 16: new EmployeeFormatted { 17: ID = emp.ID, 18: FullName = emp.LastName + ", " + emp.FirstName 19: }); 20: 21: foreach (EmployeeFormatted emp in formattedEmployees) { 22: Console.WriteLine("ID {0} Full_Name {1}", 23: emp.ID, emp.FullName); 24: } 25: Console.ReadLine(); 26: } 27: 28: static IEnumerable<T> Where<T>(IEnumerable<T> source, Func<T, bool> filter) { 29: foreach (var x in source) { 30: if (filter(x)) { 31: yield return x; 32: } 33: } 34: } 35: 36: static IEnumerable<TResult> Select<TSource, TResult>(IEnumerable<TSource> source, Func<TSource, TResult> selector) { 37: foreach (var x in source) { 38: yield return selector(x); 39: } 40: } 41: } The code outputs the same result as before. On line 14 we filter our data and on line 15 we project our data. What if we wanted to be more expressive and concise? We could combine both line 14 and 15 into one line as shown below. Assuming you had to perform several operations like this on our collection, you would end up with some very unreadable code! 1: var formattedEmployees = Select(Where(employees, emp => emp.ID % 2 == 0), (emp) => 2: new EmployeeFormatted { 3: ID = emp.ID, 4: FullName = emp.LastName + ", " + emp.FirstName 5: }); A cleaner way to write this would be to give the appearance that the Select and Where methods were part of the IEnumerable<T>. This is exactly what extension methods give us. Extension methods have to be defined in a static class. Let us make the Select and Where extension methods on IEnumerable<T> 1: public static class MyExtensionMethods { 2: static IEnumerable<T> Where<T>(this IEnumerable<T> source, Func<T, bool> filter) { 3: foreach (var x in source) { 4: if (filter(x)) { 5: yield return x; 6: } 7: } 8: } 9: 10: static IEnumerable<TResult> Select<TSource, TResult>(this IEnumerable<TSource> source, Func<TSource, TResult> selector) { 11: foreach (var x in source) { 12: yield return selector(x); 13: } 14: } 15: } The creation of the extension method makes the syntax much cleaner as shown below. We can write as many extension methods as we want and keep on chaining them using this technique. 1: var formattedEmployees = employees 2: .Where(emp => emp.ID % 2 == 0) 3: .Select (emp => new EmployeeFormatted { ID = emp.ID, FullName = emp.LastName + ", " + emp.FirstName }); Making these changes and running our code produces the same result. 1: using System; 2: using System.Collections.Generic; 3: 4: public class Program 5: { 6: [STAThread] 7: static void Main(string[] args) 8: { 9: var employees = new List<Employee> { 10: new Employee { ID = 1, FirstName = "John", LastName = "Wright", Country = "USA" }, 11: new Employee { ID = 2, FirstName = "Jim", LastName = "Ashlock", Country = "UK" }, 12: new Employee { ID = 3, FirstName = "Jane", LastName = "Jackson", Country = "CHE" }, 13: new Employee { ID = 4, FirstName = "Jill", LastName = "Anderson", Country = "AUS" } 14: }; 15: 16: var formattedEmployees = employees 17: .Where(emp => emp.ID % 2 == 0) 18: .Select (emp => 19: new EmployeeFormatted { 20: ID = emp.ID, 21: FullName = emp.LastName + ", " + emp.FirstName 22: } 23: ); 24: 25: foreach (EmployeeFormatted emp in formattedEmployees) { 26: Console.WriteLine("ID {0} Full_Name {1}", 27: emp.ID, emp.FullName); 28: } 29: Console.ReadLine(); 30: } 31: } 32: 33: public static class MyExtensionMethods { 34: static IEnumerable<T> Where<T>(this IEnumerable<T> source, Func<T, bool> filter) { 35: foreach (var x in source) { 36: if (filter(x)) { 37: yield return x; 38: } 39: } 40: } 41: 42: static IEnumerable<TResult> Select<TSource, TResult>(this IEnumerable<TSource> source, Func<TSource, TResult> selector) { 43: foreach (var x in source) { 44: yield return selector(x); 45: } 46: } 47: } 48: 49: public class Employee { 50: public int ID { get; set;} 51: public string FirstName { get; set;} 52: public string LastName {get; set;} 53: public string Country { get; set; } 54: } 55: 56: public class EmployeeFormatted { 57: public int ID { get; set; } 58: public string FullName {get; set;} 59: } Let’s change our code to return a collection of anonymous types and get rid of the EmployeeFormatted type. We see that the code produces the same output. 1: using System; 2: using System.Collections.Generic; 3: 4: public class Program 5: { 6: [STAThread] 7: static void Main(string[] args) 8: { 9: var employees = new List<Employee> { 10: new Employee { ID = 1, FirstName = "John", LastName = "Wright", Country = "USA" }, 11: new Employee { ID = 2, FirstName = "Jim", LastName = "Ashlock", Country = "UK" }, 12: new Employee { ID = 3, FirstName = "Jane", LastName = "Jackson", Country = "CHE" }, 13: new Employee { ID = 4, FirstName = "Jill", LastName = "Anderson", Country = "AUS" } 14: }; 15: 16: var formattedEmployees = employees 17: .Where(emp => emp.ID % 2 == 0) 18: .Select (emp => 19: new { 20: ID = emp.ID, 21: FullName = emp.LastName + ", " + emp.FirstName 22: } 23: ); 24: 25: foreach (var emp in formattedEmployees) { 26: Console.WriteLine("ID {0} Full_Name {1}", 27: emp.ID, emp.FullName); 28: } 29: Console.ReadLine(); 30: } 31: } 32: 33: public static class MyExtensionMethods { 34: public static IEnumerable<T> Where<T>(this IEnumerable<T> source, Func<T, bool> filter) { 35: foreach (var x in source) { 36: if (filter(x)) { 37: yield return x; 38: } 39: } 40: } 41: 42: public static IEnumerable<TResult> Select<TSource, TResult>(this IEnumerable<TSource> source, Func<TSource, TResult> selector) { 43: foreach (var x in source) { 44: yield return selector(x); 45: } 46: } 47: } 48: 49: public class Employee { 50: public int ID { get; set;} 51: public string FirstName { get; set;} 52: public string LastName {get; set;} 53: public string Country { get; set; } 54: } To be more expressive, C# allows us to write our extension method calls as a query expression. Line 16 can be rewritten a query expression like so: 1: var formattedEmployees = from emp in employees 2: where emp.ID % 2 == 0 3: select new { 4: ID = emp.ID, 5: FullName = emp.LastName + ", " + emp.FirstName 6: }; When the compiler encounters an expression like the above, it simply rewrites it as calls to our extension methods. So far we have been using our extension methods. The System.Linq namespace contains several extension methods for objects that implement the IEnumerable<T>. You can see a listing of these methods in the Enumerable class in the System.Linq namespace. Let’s get rid of our extension methods (which I purposefully wrote to be of the same signature as the ones in the Enumerable class) and use the ones provided in the Enumerable class. Our final code is shown below: 1: using System; 2: using System.Collections.Generic; 3: using System.Linq; //Added 4: 5: public class Program 6: { 7: [STAThread] 8: static void Main(string[] args) 9: { 10: var employees = new List<Employee> { 11: new Employee { ID = 1, FirstName = "John", LastName = "Wright", Country = "USA" }, 12: new Employee { ID = 2, FirstName = "Jim", LastName = "Ashlock", Country = "UK" }, 13: new Employee { ID = 3, FirstName = "Jane", LastName = "Jackson", Country = "CHE" }, 14: new Employee { ID = 4, FirstName = "Jill", LastName = "Anderson", Country = "AUS" } 15: }; 16: 17: var formattedEmployees = from emp in employees 18: where emp.ID % 2 == 0 19: select new { 20: ID = emp.ID, 21: FullName = emp.LastName + ", " + emp.FirstName 22: }; 23: 24: foreach (var emp in formattedEmployees) { 25: Console.WriteLine("ID {0} Full_Name {1}", 26: emp.ID, emp.FullName); 27: } 28: Console.ReadLine(); 29: } 30: } 31: 32: public class Employee { 33: public int ID { get; set;} 34: public string FirstName { get; set;} 35: public string LastName {get; set;} 36: public string Country { get; set; } 37: } 38: 39: public class EmployeeFormatted { 40: public int ID { get; set; } 41: public string FullName {get; set;} 42: } This post has shown you a basic overview of LINQ to Objects work by showning you how an expression is converted to a sequence of calls to extension methods when working directly with objects. It gets more interesting when working with LINQ to SQL where an expression tree is constructed – an in memory data representation of the expression. The C# compiler compiles these expressions into code that builds an expression tree at runtime. The provider can then traverse the expression tree and generate the appropriate SQL query. You can read more about expression trees in this MSDN article.

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"domain crashed" when creating new Xen instance

- by user47650

I have downloaded a Xen virtual machine image from the appscale project, and I am trying to start it up. However once I run the command; xm create -c -f xen.conf The instance immediately crashes and provides no console output. however it produces logs that I have posted below. but this is the error; [2011-03-01 12:34:03 xend.XendDomainInfo 3580] WARNING (XendDomainInfo:1178) Domain has crashed: name=appscale-1.4b id=10. I have managed to mount the root.img file locally and verify that it is actually an ext3 file system. I am running Xen 3.0.3 that is a stock RPM from the CentOS 5 repos; # rpm -qa | grep -i xen xen-libs-3.0.3-105.el5_5.5 xen-3.0.3-105.el5_5.5 xen-libs-3.0.3-105.el5_5.5 kernel-xen-2.6.18-194.32.1.el5 any suggestions on how to proceed with troubleshooting? (i am a newbie to Xen) so far I have enabled console logging, but the log file is empty. ==> domain-builder-ng.log <== xc_dom_allocate: cmdline=" ip=:1.2.3.4::::eth0:dhcp root=/dev/sda1 ro xencons=tty console=tty1 console=hvc0 debugger=y debug=y sync_console", features="" xc_dom_kernel_file: filename="/boot/vmlinuz-2.6.27-7-server" xc_dom_malloc_filemap : 2284 kB xc_dom_ramdisk_file: filename="/boot/initrd.img-2.6.27-7-server" xc_dom_malloc_filemap : 9005 kB xc_dom_boot_xen_init: ver 3.1, caps xen-3.0-x86_64 xen-3.0-x86_32p xc_dom_parse_image: called xc_dom_find_loader: trying ELF-generic loader ... failed xc_dom_find_loader: trying Linux bzImage loader ... xc_dom_malloc : 9875 kB xc_dom_do_gunzip: unzip ok, 0x234bb2 -> 0x9a4de0 OK elf_parse_binary: phdr: paddr=0x200000 memsz=0x447000 elf_parse_binary: phdr: paddr=0x647000 memsz=0xab888 elf_parse_binary: phdr: paddr=0x6f3000 memsz=0x908 elf_parse_binary: phdr: paddr=0x6f4000 memsz=0x1c2f9c elf_parse_binary: memory: 0x200000 -> 0x8b6f9c elf_xen_parse_note: GUEST_OS = "linux" elf_xen_parse_note: GUEST_VERSION = "2.6" elf_xen_parse_note: XEN_VERSION = "xen-3.0" elf_xen_parse_note: VIRT_BASE = 0xffffffff80000000 elf_xen_parse_note: ENTRY = 0xffffffff8071e200 elf_xen_parse_note: HYPERCALL_PAGE = 0xffffffff80209000 elf_xen_parse_note: FEATURES = "!writable_page_tables|pae_pgdir_above_4gb" elf_xen_parse_note: PAE_MODE = "yes" elf_xen_parse_note: LOADER = "generic" elf_xen_parse_note: unknown xen elf note (0xd) elf_xen_parse_note: SUSPEND_CANCEL = 0x1 elf_xen_parse_note: HV_START_LOW = 0xffff800000000000 elf_xen_parse_note: PADDR_OFFSET = 0x0 elf_xen_addr_calc_check: addresses: virt_base = 0xffffffff80000000 elf_paddr_offset = 0x0 virt_offset = 0xffffffff80000000 virt_kstart = 0xffffffff80200000 virt_kend = 0xffffffff808b6f9c virt_entry = 0xffffffff8071e200 xc_dom_parse_elf_kernel: xen-3.0-x86_64: 0xffffffff80200000 -> 0xffffffff808b6f9c xc_dom_mem_init: mem 1024 MB, pages 0x40000 pages, 4k each xc_dom_mem_init: 0x40000 pages xc_dom_boot_mem_init: called x86_compat: guest xen-3.0-x86_64, address size 64 xc_dom_malloc : 2048 kB ==> xend.log <== [2011-03-01 12:34:01 xend.XendDomainInfo 3580] INFO (XendDomainInfo:2330) Dev 2049 still active, looping... [2011-03-01 12:34:01 xend.XendDomainInfo 3580] INFO (XendDomainInfo:2330) Dev 2049 still active, looping... [2011-03-01 12:34:01 xend.XendDomainInfo 3580] INFO (XendDomainInfo:2330) Dev 2049 still active, looping... [2011-03-01 12:34:01 xend.XendDomainInfo 3580] INFO (XendDomainInfo:2330) Dev 2049 still active, looping... [2011-03-01 12:34:01 xend.XendDomainInfo 3580] INFO (XendDomainInfo:957) Dev 0 still active, looping... [2011-03-01 12:34:01 xend.XendDomainInfo 3580] INFO (XendDomainInfo:957) Dev 0 still active, looping... [2011-03-01 12:34:01 xend.XendDomainInfo 3580] INFO (XendDomainInfo:957) Dev 0 still active, looping... [2011-03-01 12:34:02 xend.XendDomainInfo 3580] INFO (XendDomainInfo:957) Dev 0 still active, looping... [2011-03-01 12:34:02 xend.XendDomainInfo 3580] DEBUG (XendDomainInfo:2114) UUID Created: True [2011-03-01 12:34:02 xend.XendDomainInfo 3580] DEBUG (XendDomainInfo:2115) Devices to release: [], domid = 9 [2011-03-01 12:34:02 xend.XendDomainInfo 3580] DEBUG (XendDomainInfo:2127) Releasing PVFB backend devices ... [2011-03-01 12:34:02 xend.XendDomainInfo 3580] DEBUG (XendDomainInfo:207) XendDomainInfo.create(['domain', ['domid', 9], ['uuid', 'd5f22dd4-8dc2-f51f-84e9-eea7d71ea1d0'], ['vcpus', 1], ['vcpu_avail', 1], ['cpu_cap', 0], ['cpu_weight', 256], ['memory', 1024], ['shadow_memory', 0], ['maxmem', 1024], ['features', ''], ['name', 'appscale-1.4b'], ['on_poweroff', 'destroy'], ['on_reboot', 'restart'], ['on_crash', 'restart'], ['image', ['linux', ['kernel', '/boot/vmlinuz-2.6.27-7-server'], ['ramdisk', '/boot/initrd.img-2.6.27-7-server'], ['ip', ':1.2.3.4::::eth0:dhcp'], ['root', '/dev/sda1 ro'], ['args', 'xencons=tty console=tty1 console=hvc0 debugger=y debug=y sync_console']]], ['cpus', []], ['device', ['vif', ['backend', 0], ['script', 'vif-bridge'], ['mac', '00:16:3B:72:10:E4']]], ['device', ['vbd', ['backend', 0], ['dev', 'sda1:disk'], ['uname', 'file:/local/xen/domains/appscale1.4/root.img'], ['mode', 'w']]], ['state', '----c-'], ['shutdown_reason', 'crash'], ['cpu_time', 0.000339131], ['online_vcpus', 1], ['up_time', '0.952092885971'], ['start_time', '1299011639.92'], ['store_mfn', 1169289], ['console_mfn', 1169288]]) [2011-03-01 12:34:02 xend.XendDomainInfo 3580] DEBUG (XendDomainInfo:329) parseConfig: config is ['domain', ['domid', 9], ['uuid', 'd5f22dd4-8dc2-f51f-84e9-eea7d71ea1d0'], ['vcpus', 1], ['vcpu_avail', 1], ['cpu_cap', 0], ['cpu_weight', 256], ['memory', 1024], ['shadow_memory', 0], ['maxmem', 1024], ['features', ''], ['name', 'appscale-1.4b'], ['on_poweroff', 'destroy'], ['on_reboot', 'restart'], ['on_crash', 'restart'], ['image', ['linux', ['kernel', '/boot/vmlinuz-2.6.27-7-server'], ['ramdisk', '/boot/initrd.img-2.6.27-7-server'], ['ip', ':1.2.3.4::::eth0:dhcp'], ['root', '/dev/sda1 ro'], ['args', 'xencons=tty console=tty1 console=hvc0 debugger=y debug=y sync_console']]], ['cpus', []], ['device', ['vif', ['backend', 0], ['script', 'vif-bridge'], ['mac', '00:16:3B:72:10:E4']]], ['device', ['vbd', ['backend', 0], ['dev', 'sda1:disk'], ['uname', 'file:/local/xen/domains/appscale1.4/root.img'], ['mode', 'w']]], ['state', '----c-'], ['shutdown_reason', 'crash'], ['cpu_time', 0.000339131], ['online_vcpus', 1], ['up_time', '0.952092885971'], ['start_time', '1299011639.92'], ['store_mfn', 1169289], ['console_mfn', 1169288]] [2011-03-01 12:34:02 xend.XendDomainInfo 3580] DEBUG (XendDomainInfo:446) parseConfig: result is {'features': '', 'image': ['linux', ['kernel', '/boot/vmlinuz-2.6.27-7-server'], ['ramdisk', '/boot/initrd.img-2.6.27-7-server'], ['ip', ':1.2.3.4::::eth0:dhcp'], ['root', '/dev/sda1 ro'], ['args', 'xencons=tty console=tty1 console=hvc0 debugger=y debug=y sync_console']], 'cpus': [], 'vcpu_avail': 1, 'backend': [], 'uuid': 'd5f22dd4-8dc2-f51f-84e9-eea7d71ea1d0', 'on_reboot': 'restart', 'cpu_weight': 256.0, 'memory': 1024, 'cpu_cap': 0, 'localtime': None, 'timer_mode': None, 'start_time': 1299011639.9200001, 'on_poweroff': 'destroy', 'on_crash': 'restart', 'device': [('vif', ['vif', ['backend', 0], ['script', 'vif-bridge'], ['mac', '00:16:3B:72:10:E4']]), ('vbd', ['vbd', ['backend', 0], ['dev', 'sda1:disk'], ['uname', 'file:/local/xen/domains/appscale1.4/root.img'], ['mode', 'w']])], 'bootloader': None, 'maxmem': 1024, 'shadow_memory': 0, 'name': 'appscale-1.4b', 'bootloader_args': None, 'vcpus': 1, 'cpu': None} [2011-03-01 12:34:02 xend.XendDomainInfo 3580] DEBUG (XendDomainInfo:1784) XendDomainInfo.construct: None [2011-03-01 12:34:02 xend 3580] DEBUG (balloon:145) Balloon: 3034420 KiB free; need 4096; done. [2011-03-01 12:34:02 xend.XendDomainInfo 3580] DEBUG (XendDomainInfo:1953) XendDomainInfo.initDomain: 10 256.0 [2011-03-01 12:34:02 xend.XendDomainInfo 3580] DEBUG (XendDomainInfo:1994) _initDomain:shadow_memory=0x0, maxmem=0x400, memory=0x400. [2011-03-01 12:34:02 xend 3580] DEBUG (balloon:145) Balloon: 3034412 KiB free; need 1048576; done. [2011-03-01 12:34:02 xend 3580] INFO (image:139) buildDomain os=linux dom=10 vcpus=1 [2011-03-01 12:34:02 xend 3580] DEBUG (image:208) domid = 10 [2011-03-01 12:34:02 xend 3580] DEBUG (image:209) memsize = 1024 [2011-03-01 12:34:02 xend 3580] DEBUG (image:210) image = /boot/vmlinuz-2.6.27-7-server [2011-03-01 12:34:02 xend 3580] DEBUG (image:211) store_evtchn = 1 [2011-03-01 12:34:02 xend 3580] DEBUG (image:212) console_evtchn = 2 [2011-03-01 12:34:02 xend 3580] DEBUG (image:213) cmdline = ip=:1.2.3.4::::eth0:dhcp root=/dev/sda1 ro xencons=tty console=tty1 console=hvc0 debugger=y debug=y sync_console [2011-03-01 12:34:02 xend 3580] DEBUG (image:214) ramdisk = /boot/initrd.img-2.6.27-7-server [2011-03-01 12:34:02 xend 3580] DEBUG (image:215) vcpus = 1 [2011-03-01 12:34:02 xend 3580] DEBUG (image:216) features = ==> domain-builder-ng.log <== xc_dom_build_image: called xc_dom_alloc_segment: kernel : 0xffffffff80200000 -> 0xffffffff808b7000 (pfn 0x200 + 0x6b7 pages) xc_dom_pfn_to_ptr: domU mapping: pfn 0x200+0x6b7 at 0x2aaaab5f6000 elf_load_binary: phdr 0 at 0x0x2aaaab5f6000 -> 0x0x2aaaaba3d000 elf_load_binary: phdr 1 at 0x0x2aaaaba3d000 -> 0x0x2aaaabae8888 elf_load_binary: phdr 2 at 0x0x2aaaabae9000 -> 0x0x2aaaabae9908 elf_load_binary: phdr 3 at 0x0x2aaaabaea000 -> 0x0x2aaaabb9a004 xc_dom_alloc_segment: ramdisk : 0xffffffff808b7000 -> 0xffffffff82382000 (pfn 0x8b7 + 0x1acb pages) xc_dom_malloc : 160 kB xc_dom_pfn_to_ptr: domU mapping: pfn 0x8b7+0x1acb at 0x2aaab0000000 xc_dom_do_gunzip: unzip ok, 0x8cb5e7 -> 0x1aca210 xc_dom_alloc_segment: phys2mach : 0xffffffff82382000 -> 0xffffffff82582000 (pfn 0x2382 + 0x200 pages) xc_dom_pfn_to_ptr: domU mapping: pfn 0x2382+0x200 at 0x2aaab1acb000 xc_dom_alloc_page : start info : 0xffffffff82582000 (pfn 0x2582) xc_dom_alloc_page : xenstore : 0xffffffff82583000 (pfn 0x2583) xc_dom_alloc_page : console : 0xffffffff82584000 (pfn 0x2584) nr_page_tables: 0x0000ffffffffffff/48: 0xffff000000000000 -> 0xffffffffffffffff, 1 table(s) nr_page_tables: 0x0000007fffffffff/39: 0xffffff8000000000 -> 0xffffffffffffffff, 1 table(s) nr_page_tables: 0x000000003fffffff/30: 0xffffffff80000000 -> 0xffffffffbfffffff, 1 table(s) nr_page_tables: 0x00000000001fffff/21: 0xffffffff80000000 -> 0xffffffff827fffff, 20 table(s) xc_dom_alloc_segment: page tables : 0xffffffff82585000 -> 0xffffffff8259c000 (pfn 0x2585 + 0x17 pages) xc_dom_pfn_to_ptr: domU mapping: pfn 0x2585+0x17 at 0x2aaab1ccb000 xc_dom_alloc_page : boot stack : 0xffffffff8259c000 (pfn 0x259c) xc_dom_build_image : virt_alloc_end : 0xffffffff8259d000 xc_dom_build_image : virt_pgtab_end : 0xffffffff82800000 xc_dom_boot_image: called arch_setup_bootearly: doing nothing xc_dom_compat_check: supported guest type: xen-3.0-x86_64 <= matches xc_dom_compat_check: supported guest type: xen-3.0-x86_32p xc_dom_update_guest_p2m: dst 64bit, pages 0x40000 clear_page: pfn 0x2584, mfn 0x11d788 clear_page: pfn 0x2583, mfn 0x11d789 xc_dom_pfn_to_ptr: domU mapping: pfn 0x2582+0x1 at 0x2aaab1ce2000 start_info_x86_64: called setup_hypercall_page: vaddr=0xffffffff80209000 pfn=0x209 domain builder memory footprint allocated malloc : 12139 kB anon mmap : 0 bytes mapped file mmap : 11289 kB domU mmap : 35 MB arch_setup_bootlate: shared_info: pfn 0x0, mfn 0xd6fe1 shared_info_x86_64: called vcpu_x86_64: called vcpu_x86_64: cr3: pfn 0x2585 mfn 0x11d787 launch_vm: called, ctxt=0x97b21f8 xc_dom_release: called ==> xend.log <== [2011-03-01 12:34:02 xend 3580] DEBUG (DevController:114) DevController: writing {'mac': '00:16:3B:72:10:E4', 'handle': '0', 'protocol': 'x86_64-abi', 'backend-id': '0', 'state': '1', 'backend': '/local/domain/0/backend/vif/10/0'} to /local/domain/10/device/vif/0. [2011-03-01 12:34:02 xend 3580] DEBUG (DevController:116) DevController: writing {'domain': 'appscale-1.4b', 'handle': '0', 'script': '/etc/xen/scripts/vif-bridge', 'state': '1', 'frontend': '/local/domain/10/device/vif/0', 'mac': '00:16:3B:72:10:E4', 'online': '1', 'frontend-id': '10'} to /local/domain/0/backend/vif/10/0. [2011-03-01 12:34:02 xend.XendDomainInfo 3580] DEBUG (XendDomainInfo:634) Checking for duplicate for uname: /local/xen/domains/appscale1.4/root.img [file:/local/xen/domains/appscale1.4/root.img], dev: sda1:disk, mode: w [2011-03-01 12:34:02 xend 3580] DEBUG (blkif:27) exception looking up device number for sda1:disk: [Errno 2] No such file or directory: '/dev/sda1:disk' [2011-03-01 12:34:02 xend 3580] DEBUG (blkif:27) exception looking up device number for sda1: [Errno 2] No such file or directory: '/dev/sda1' [2011-03-01 12:34:02 xend 3580] DEBUG (DevController:114) DevController: writing {'virtual-device': '2049', 'device-type': 'disk', 'protocol': 'x86_64-abi', 'backend-id': '0', 'state': '1', 'backend': '/local/domain/0/backend/vbd/10/2049'} to /local/domain/10/device/vbd/2049. [2011-03-01 12:34:02 xend 3580] DEBUG (DevController:116) DevController: writing {'domain': 'appscale-1.4b', 'frontend': '/local/domain/10/device/vbd/2049', 'format': 'raw', 'dev': 'sda1', 'state': '1', 'params': '/local/xen/domains/appscale1.4/root.img', 'mode': 'w', 'online': '1', 'frontend-id': '10', 'type': 'file'} to /local/domain/0/backend/vbd/10/2049. [2011-03-01 12:34:02 xend.XendDomainInfo 3580] DEBUG (XendDomainInfo:993) Storing VM details: {'shadow_memory': '0', 'uuid': 'd5f22dd4-8dc2-f51f-84e9-eea7d71ea1d0', 'on_reboot': 'restart', 'start_time': '1299011642.74', 'on_poweroff': 'destroy', 'name': 'appscale-1.4b', 'xend/restart_count': '0', 'vcpus': '1', 'vcpu_avail': '1', 'memory': '1024', 'on_crash': 'restart', 'image': "(linux (kernel /boot/vmlinuz-2.6.27-7-server) (ramdisk /boot/initrd.img-2.6.27-7-server) (ip :1.2.3.4::::eth0:dhcp) (root '/dev/sda1 ro') (args 'xencons=tty console=tty1 console=hvc0 debugger=y debug=y sync_console'))", 'maxmem': '1024'} [2011-03-01 12:34:02 xend.XendDomainInfo 3580] DEBUG (XendDomainInfo:1028) Storing domain details: {'console/ring-ref': '1169288', 'console/port': '2', 'name': 'appscale-1.4b', 'console/limit': '1048576', 'vm': '/vm/d5f22dd4-8dc2-f51f-84e9-eea7d71ea1d0', 'domid': '10', 'cpu/0/availability': 'online', 'memory/target': '1048576', 'store/ring-ref': '1169289', 'store/port': '1'} [2011-03-01 12:34:02 xend 3580] DEBUG (DevController:158) Waiting for devices vif. [2011-03-01 12:34:02 xend 3580] DEBUG (DevController:164) Waiting for 0. [2011-03-01 12:34:02 xend.XendDomainInfo 3580] DEBUG (XendDomainInfo:1250) XendDomainInfo.handleShutdownWatch [2011-03-01 12:34:02 xend 3580] DEBUG (DevController:509) hotplugStatusCallback /local/domain/0/backend/vif/10/0/hotplug-status. [2011-03-01 12:34:03 xend 3580] DEBUG (DevController:509) hotplugStatusCallback /local/domain/0/backend/vif/10/0/hotplug-status. [2011-03-01 12:34:03 xend 3580] DEBUG (DevController:523) hotplugStatusCallback 1. [2011-03-01 12:34:03 xend 3580] DEBUG (DevController:158) Waiting for devices usb. [2011-03-01 12:34:03 xend 3580] DEBUG (DevController:158) Waiting for devices vbd. [2011-03-01 12:34:03 xend 3580] DEBUG (DevController:164) Waiting for 2049. [2011-03-01 12:34:03 xend 3580] DEBUG (DevController:509) hotplugStatusCallback /local/domain/0/backend/vbd/10/2049/hotplug-status. [2011-03-01 12:34:03 xend 3580] DEBUG (DevController:509) hotplugStatusCallback /local/domain/0/backend/vbd/10/2049/hotplug-status. [2011-03-01 12:34:03 xend 3580] DEBUG (DevController:523) hotplugStatusCallback 1. [2011-03-01 12:34:03 xend 3580] DEBUG (DevController:158) Waiting for devices irq. [2011-03-01 12:34:03 xend 3580] DEBUG (DevController:158) Waiting for devices vkbd. [2011-03-01 12:34:03 xend 3580] DEBUG (DevController:158) Waiting for devices vfb. [2011-03-01 12:34:03 xend 3580] DEBUG (DevController:158) Waiting for devices pci. [2011-03-01 12:34:03 xend 3580] DEBUG (DevController:158) Waiting for devices ioports. [2011-03-01 12:34:03 xend 3580] DEBUG (DevController:158) Waiting for devices tap. [2011-03-01 12:34:03 xend 3580] DEBUG (DevController:158) Waiting for devices vtpm. [2011-03-01 12:34:03 xend.XendDomainInfo 3580] WARNING (XendDomainInfo:1178) Domain has crashed: name=appscale-1.4b id=10. [2011-03-01 12:34:03 xend.XendDomainInfo 3580] ERROR (XendDomainInfo:2654) VM appscale-1.4b restarting too fast (2.275545 seconds since the last restart). Refusing to restart to avoid loops. [2011-03-01 12:34:03 xend.XendDomainInfo 3580] DEBUG (XendDomainInfo:2189) XendDomainInfo.destroy: domid=10 ==> xen-hotplug.log <== Nothing to flush. ==> xend.log <== [2011-03-01 12:34:03 xend.XendDomainInfo 3580] INFO (XendDomainInfo:2330) Dev 2049 still active, looping... [2011-03-01 12:34:03 xend.XendDomainInfo 3580] INFO (XendDomainInfo:2330) Dev 2049 still active, looping... [2011-03-01 12:34:03 xend.XendDomainInfo 3580] INFO (XendDomainInfo:2330) Dev 2049 still active, looping... [2011-03-01 12:34:03 xend.XendDomainInfo 3580] INFO (XendDomainInfo:2330) Dev 2049 still active, looping... [2011-03-01 12:34:03 xend.XendDomainInfo 3580] INFO (XendDomainInfo:2330) Dev 2049 still active, looping... [2011-03-01 12:34:03 xend.XendDomainInfo 3580] DEBUG (XendDomainInfo:2114) UUID Created: True [2011-03-01 12:34:03 xend.XendDomainInfo 3580] DEBUG (XendDomainInfo:2115) Devices to release: [], domid = 10 [2011-03-01 12:34:03 xend.XendDomainInfo 3580] DEBUG (XendDomainInfo:2127) Releasing PVFB backend devices ... And this is the xen.conf file that I am using; # cat xen.conf # Configuration file for the Xen instance AppScale, created # bn VMBuilder kernel = '/boot/vmlinuz-2.6.27-7-server' ramdisk = '/boot/initrd.img-2.6.27-7-server' memory = 1024 vcpus = 1 root = '/dev/sda1 ro' disk = [ 'file:/local/xen/domains/appscale1.4/root.img,sda1,w', ] name = 'appscale-1.4b' dhcp = 'dhcp' vif = [ 'mac=00:16:3B:72:10:E4' ] on_poweroff = 'destroy' on_reboot = 'restart' on_crash = 'restart' extra = 'xencons=tty console=tty1 console=hvc0 debugger=y debug=y sync_console'

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java.lang.ClassCastException: java.lang.Integer cannot be cast to java.util.HashMap

- by kongkea

I've got this Error When I click listview to show full image size. how can i solve it? Error 11-20 10:27:47.039: D/AndroidRuntime(5078): Shutting down VM 11-20 10:27:47.039: W/dalvikvm(5078): threadid=1: thread exiting with uncaught exception (group=0x40c061f8) 11-20 10:27:47.047: E/AndroidRuntime(5078): FATAL EXCEPTION: main 11-20 10:27:47.047: E/AndroidRuntime(5078): java.lang.ClassCastException: java.lang.Integer cannot be cast to java.util.HashMap 11-20 10:27:47.047: E/AndroidRuntime(5078): at com.example.mylistview.MainActivity$1.onItemClick(MainActivity.java:103) 11-20 10:27:47.047: E/AndroidRuntime(5078): at android.widget.AdapterView.performItemClick(AdapterView.java:292) 11-20 10:27:47.047: E/AndroidRuntime(5078): at android.widget.AbsListView.performItemClick(AbsListView.java:1173) 11-20 10:27:47.047: E/AndroidRuntime(5078): at android.widget.AbsListView$PerformClick.run(AbsListView.java:2701) 11-20 10:27:47.047: E/AndroidRuntime(5078): at android.widget.AbsListView$1.run(AbsListView.java:3453) 11-20 10:27:47.047: E/AndroidRuntime(5078): at android.os.Handler.handleCallback(Handler.java:605) 11-20 10:27:47.047: E/AndroidRuntime(5078): at android.os.Handler.dispatchMessage(Handler.java:92) 11-20 10:27:47.047: E/AndroidRuntime(5078): at android.os.Looper.loop(Looper.java:137) 11-20 10:27:47.047: E/AndroidRuntime(5078): at android.app.ActivityThread.main(ActivityThread.java:4514) 11-20 10:27:47.047: E/AndroidRuntime(5078): at java.lang.reflect.Method.invokeNative(Native Method) 11-20 10:27:47.047: E/AndroidRuntime(5078): at java.lang.reflect.Method.invoke(Method.java:511) 11-20 10:27:47.047: E/AndroidRuntime(5078): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:790) 11-20 10:27:47.047: E/AndroidRuntime(5078): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:557) 11-20 10:27:47.047: E/AndroidRuntime(5078): at dalvik.system.NativeStart.main(Native Method) MainActivity public class MainActivity extends Activity { public static final int DIALOG_DOWNLOAD_JSON_PROGRESS = 0; private ProgressDialog mProgressDialog; ArrayList<HashMap<String, Object>> MyArrList; @SuppressLint("NewApi") @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); // Permission StrictMode if (android.os.Build.VERSION.SDK_INT > 9) { StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build(); StrictMode.setThreadPolicy(policy); } // Download JSON File new DownloadJSONFileAsync().execute(); } @Override protected Dialog onCreateDialog(int id) { switch (id) { case DIALOG_DOWNLOAD_JSON_PROGRESS: mProgressDialog = new ProgressDialog(this); mProgressDialog.setMessage("Downloading....."); mProgressDialog.setProgressStyle(ProgressDialog.STYLE_SPINNER); mProgressDialog.setCancelable(true); mProgressDialog.show(); return mProgressDialog; default: return null; } } // Show All Content public void ShowAllContent() { // listView1 final ListView lstView1 = (ListView)findViewById(R.id.listView1); lstView1.setAdapter(new ImageAdapter(MainActivity.this,MyArrList)); lstView1.setOnItemClickListener(new OnItemClickListener() { @Override public void onItemClick(AdapterView<?> parent, View v, int position, long id) { HashMap<String, Object> hm = (HashMap<String, Object>) lstView1.getAdapter().getItem(position); String imagePath = (String) hm.get("photo"); Intent i = new Intent(MainActivity.this,FullImageActivity.class); i.putExtra("fullImage", imagePath); startActivity(i); } }); } public class ImageAdapter extends BaseAdapter { private Context context; private ArrayList<HashMap<String, Object>> MyArr = new ArrayList<HashMap<String, Object>>(); public ImageAdapter(Context c, ArrayList<HashMap<String, Object>> myArrList) { // TODO Auto-generated method stub context = c; MyArr = myArrList; } public int getCount() { // TODO Auto-generated method stub return MyArr.size(); } public Object getItem(int position) { // TODO Auto-generated method stub return position; } public long getItemId(int position) { // TODO Auto-generated method stub return position; } public View getView(int position, View convertView, ViewGroup parent) { // TODO Auto-generated method stub LayoutInflater inflater = (LayoutInflater) context .getSystemService(Context.LAYOUT_INFLATER_SERVICE); if (convertView == null) { convertView = inflater.inflate(R.layout.activity_column, null); } // ColImage ImageView imageView = (ImageView) convertView.findViewById(R.id.ColImgPath); imageView.getLayoutParams().height = 80; imageView.getLayoutParams().width = 80; imageView.setPadding(5, 5, 5, 5); imageView.setScaleType(ImageView.ScaleType.CENTER_CROP); try { imageView.setImageBitmap((Bitmap)MyArr.get(position).get("ImageThumBitmap")); } catch (Exception e) { // When Error imageView.setImageResource(android.R.drawable.ic_menu_report_image); } // ColImgID TextView txtImgID = (TextView) convertView.findViewById(R.id.ColImgID); txtImgID.setPadding(10, 0, 0, 0); txtImgID.setText("ID : " + MyArr.get(position).get("id").toString()); // ColImgName TextView txtPicName = (TextView) convertView.findViewById(R.id.ColImgName); txtPicName.setPadding(50, 0, 0, 0); txtPicName.setText("Name : " + MyArr.get(position).get("first_name").toString()); return convertView; } } // Download JSON in Background public class DownloadJSONFileAsync extends AsyncTask<String, Void, Void> { protected void onPreExecute() { super.onPreExecute(); showDialog(DIALOG_DOWNLOAD_JSON_PROGRESS); } @Override protected Void doInBackground(String... params) { // TODO Auto-generated method stub String url = "http://192.168.10.104/adchara1/"; JSONArray data; try { data = new JSONArray(getJSONUrl(url)); MyArrList = new ArrayList<HashMap<String, Object>>(); HashMap<String, Object> map; for(int i = 0; i < data.length(); i++){ JSONObject c = data.getJSONObject(i); map = new HashMap<String, Object>(); map.put("id", (String)c.getString("id")); map.put("first_name", (String)c.getString("first_name")); // Thumbnail Get ImageBitmap To Object map.put("photo", (String)c.getString("photo")); map.put("ImageThumBitmap", (Bitmap)loadBitmap(c.getString("photo"))); // Full (for View Popup) map.put("frame", (String)c.getString("frame")); MyArrList.add(map); } } catch (JSONException e) { // TODO Auto-generated catch block e.printStackTrace(); } return null; } protected void onPostExecute(Void unused) { ShowAllContent(); // When Finish Show Content dismissDialog(DIALOG_DOWNLOAD_JSON_PROGRESS); removeDialog(DIALOG_DOWNLOAD_JSON_PROGRESS); } } /*** Get JSON Code from URL ***/ public String getJSONUrl(String url) { StringBuilder str = new StringBuilder(); HttpClient client = new DefaultHttpClient(); HttpGet httpGet = new HttpGet(url); try { HttpResponse response = client.execute(httpGet); StatusLine statusLine = response.getStatusLine(); int statusCode = statusLine.getStatusCode(); if (statusCode == 200) { // Download OK HttpEntity entity = response.getEntity(); InputStream content = entity.getContent(); BufferedReader reader = new BufferedReader(new InputStreamReader(content)); String line; while ((line = reader.readLine()) != null) { str.append(line); } } else { Log.e("Log", "Failed to download file.."); } } catch (ClientProtocolException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } return str.toString(); } /***** Get Image Resource from URL (Start) *****/ private static final String TAG = "Image"; private static final int IO_BUFFER_SIZE = 4 * 1024; public static Bitmap loadBitmap(String url) { Bitmap bitmap = null; InputStream in = null; BufferedOutputStream out = null; try { in = new BufferedInputStream(new URL(url).openStream(), IO_BUFFER_SIZE); final ByteArrayOutputStream dataStream = new ByteArrayOutputStream(); out = new BufferedOutputStream(dataStream, IO_BUFFER_SIZE); copy(in, out); out.flush(); final byte[] data = dataStream.toByteArray(); BitmapFactory.Options options = new BitmapFactory.Options(); //options.inSampleSize = 1; bitmap = BitmapFactory.decodeByteArray(data, 0, data.length,options); } catch (IOException e) { Log.e(TAG, "Could not load Bitmap from: " + url); } finally { closeStream(in); closeStream(out); } return bitmap; } private static void closeStream(Closeable stream) { if (stream != null) { try { stream.close(); } catch (IOException e) { android.util.Log.e(TAG, "Could not close stream", e); } } } private static void copy(InputStream in, OutputStream out) throws IOException { byte[] b = new byte[IO_BUFFER_SIZE]; int read; while ((read = in.read(b)) != -1) { out.write(b, 0, read); } } /***** Get Image Resource from URL (End) *****/ @Override public boolean onCreateOptionsMenu(Menu menu) { getMenuInflater().inflate(R.menu.activity_main, menu); return true; } } FullImageActivity String imagePath = getIntent().getStringExtra("fullImage"); if(imagePath != null && !imagePath.isEmpty()){ File imageFile = new File(imagePath); if(imageFile.exists()){ Bitmap myBitmap = BitmapFactory.decodeFile(imageFile.getAbsolutePath()); ImageView iv = (ImageView) findViewById(R.id.fullimage); iv.setImageBitmap(myBitmap); } }

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ASP.Net How to enforce the HTTP get URL format?

- by Hamish Grubijan

[Sorry about a messy question. I believe I am targeting .Net 2.0 (for now)] Hi, I am an ASP.NET noob. For starters I am building a page that parses a URL string and populates a table in a database. I want that string to be strictly of the form: http://<server>:<port>/PageName.aspx?A=1&B=2&C=3&D=4&E=5 The order of the arguments do not matter, I just do not want any of them missing, or any extras. Here is what I tried (yes, it is ugly; I just want to get it to work first): #if (DEBUG) // Maps parameter names to their human readable names. // Used for error checking. private static Dictionary<string, string> paramNameToDisplayName = new Dictionary<string, string> { { A, "a"}, { B, "b"}, { C, "c"}, { D, "d"}, { E, "e"}, { F, "f"}, }; [Conditional("DEBUG")] private void validateRequestParameters(HttpRequest request) { bool endResponse = false; // Use foreach var foreach (string expectedParameterName in paramNameToDisplayName.Keys) { if (request[expectedParameterName] == null) { Response.Write(String.Format("No parameter \"{0}\", aka {1} was passed to the configuration generator. Check your URL string / cookie.", expectedParameterName, paramNameToDisplayName[expectedParameterName])); endResponse = true; } } // Use foreach var foreach (string actualParameterName in request.Params) { if (!paramNameToDisplayName.ContainsKey(actualParameterName)) { Response.Write(String.Format("The parameter \"{0}\", was passed to the configuration generator, but it was not expected. Check your URL string / cookie.", actualParameterName)); endResponse = true; } } if (endResponse) { Response.End(); } } #endif and it works ok, except that it complains about all sorts of other stuff: http://localhost:1796/AddStatusUpdate.aspx?X=0 No parameter "A", aka a was passed to the configuration generator. Check your URL string / cookie.No parameter "B", aka b was passed to the configuration generator. Check your URL string / cookie.No parameter "C", aka c was passed to the configuration generator. Check your URL string / cookie.No parameter "D", aka d was passed to the configuration generator. Check your URL string / cookie.No parameter "E", aka e was passed to the configuration generator. Check your URL string / cookie.No parameter "F", aka f was passed to the configuration generator. Check your URL string / cookie.The parameter "X", was passed to the configuration generator, but it was not expected. Check your URL string / cookie.The parameter "ASP.NET_SessionId", was passed to the configuration generator, but it was not expected. Check your URL string / cookie.The parameter "ALL_HTTP", was passed to the configuration generator, but it was not expected. Check your URL string / cookie.The parameter "ALL_RAW", was passed to the configuration generator, but it was not expected. Check your URL string / cookie.The parameter "APPL_MD_PATH", was passed to the configuration generator, but it was not expected. Check your URL string / cookie.The parameter "APPL_PHYSICAL_PATH", was passed to the configuration generator, but it was not expected. Check your URL string / cookie.The parameter "AUTH_TYPE", was passed to the configuration generator, but it was not expected. Check your URL string / cookie.The parameter "AUTH_USER", was passed to the configuration generator, but it was not expected. Check your URL string / cookie.The parameter "AUTH_PASSWORD", was passed to the configuration generator, but it was not expected. Check your URL string / cookie.The parameter "LOGON_USER", was passed to the configuration generator, but it was not expected. Check your URL string / cookie.The parameter "REMOTE_USER", was passed to the configuration generator, but it was not expected. Check your URL string / cookie.The parameter "CERT_COOKIE", was passed to the configuration generator, but it was not expected. Check your URL string / cookie.The parameter "CERT_FLAGS", was passed to the configuration generator, but it was not expected. Check your URL string / cookie.The parameter "CERT_ISSUER", was passed to the configuration generator, but it was not expected. Check your URL string / cookie.The parameter "CERT_KEYSIZE", was passed to the configuration generator, but it was not expected. Check your URL string / cookie.The parameter "CERT_SECRETKEYSIZE", was passed to the configuration generator, but it was not expected. Check your URL string / cookie.The parameter "CERT_SERIALNUMBER", was passed to the configuration generator, but it was not expected. Check your URL string / cookie.The parameter "CERT_SERVER_ISSUER", was passed to the configuration generator, but it was not expected. Check your URL string / cookie.The parameter "CERT_SERVER_SUBJECT", was passed to the configuration generator, but it was not expected. Check your URL string / cookie.The parameter "CERT_SUBJECT", was passed to the configuration generator, but it was not expected. Check your URL string / cookie.The parameter "CONTENT_LENGTH", was passed to the configuration generator, but it was not expected. Check your URL string / cookie.The parameter "CONTENT_TYPE", was passed to the configuration generator, but it was not expected. Check your URL string / cookie.The parameter "GATEWAY_INTERFACE", was passed to the configuration generator, but it was not expected. Check your URL string / cookie.The parameter "HTTPS", was passed to the configuration generator, but it was not expected. Check your URL string / cookie.The parameter "HTTPS_KEYSIZE", was passed to the configuration generator, but it was not expected. Check your URL string / cookie.The parameter "HTTPS_SECRETKEYSIZE", was passed to the configuration generator, but it was not expected. Check your URL string / cookie.The parameter "HTTPS_SERVER_ISSUER", was passed to the configuration generator, but it was not expected. Check your URL string / cookie.The parameter "HTTPS_SERVER_SUBJECT", was passed to the configuration generator, but it was not expected. Check your URL string / cookie.The parameter "INSTANCE_ID", was passed to the configuration generator, but it was not expected. Check your URL string / cookie.The parameter "INSTANCE_META_PATH", was passed to the configuration generator, but it was not expected. Check your URL string / cookie.The parameter "LOCAL_ADDR", was passed to the configuration generator, but it was not expected. Check your URL string / cookie.The parameter "PATH_INFO", was passed to the configuration generator, but it was not expected. Check your URL string / cookie.The parameter "PATH_TRANSLATED", was passed to the configuration generator, but it was not expected. Check your URL string / cookie.The parameter "QUERY_STRING", was passed to the configuration generator, but it was not expected. Check your URL string / cookie.The parameter "REMOTE_ADDR", was passed to the configuration generator, but it was not expected. Check your URL string / cookie.The parameter "REMOTE_HOST", was passed to the configuration generator, but it was not expected. Check your URL string / cookie.The parameter "REMOTE_PORT", was passed to the configuration generator, but it was not expected. Check your URL string / cookie.The parameter "REQUEST_METHOD", was passed to the configuration generator, but it was not expected. Check your URL string / cookie.The parameter "SCRIPT_NAME", was passed to the configuration generator, but it was not expected. Check your URL string / cookie.The parameter "SERVER_NAME", was passed to the configuration generator, but it was not expected. Check your URL string / cookie.The parameter "SERVER_PORT", was passed to the configuration generator, but it was not expected. Check your URL string / cookie.The parameter "SERVER_PORT_SECURE", was passed to the configuration generator, but it was not expected. Check your URL string / cookie.The parameter "SERVER_PROTOCOL", was passed to the configuration generator, but it was not expected. Check your URL string / cookie.The parameter "SERVER_SOFTWARE", was passed to the configuration generator, but it was not expected. Check your URL string / cookie.The parameter "URL", was passed to the configuration generator, but it was not expected. Check your URL string / cookie.The parameter "HTTP_CACHE_CONTROL", was passed to the configuration generator, but it was not expected. Check your URL string / cookie.The parameter "HTTP_CONNECTION", was passed to the configuration generator, but it was not expected. Check your URL string / cookie.The parameter "HTTP_ACCEPT", was passed to the configuration generator, but it was not expected. Check your URL string / cookie.The parameter "HTTP_ACCEPT_CHARSET", was passed to the configuration generator, but it was not expected. Check your URL string / cookie.The parameter "HTTP_ACCEPT_ENCODING", was passed to the configuration generator, but it was not expected. Check your URL string / cookie.The parameter "HTTP_ACCEPT_LANGUAGE", was passed to the configuration generator, but it was not expected. Check your URL string / cookie.The parameter "HTTP_COOKIE", was passed to the configuration generator, but it was not expected. Check your URL string / cookie.The parameter "HTTP_HOST", was passed to the configuration generator, but it was not expected. Check your URL string / cookie.The parameter "HTTP_USER_AGENT", was passed to the configuration generator, but it was not expected. Check your URL string / cookie.Thread was being aborted. Is there some way for me to separate the implicit and the explicit parameters, or is it not doable? Should I even bother? Perhaps the philosophy of get is to just throw away that what is not needed. Thanks!

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php security holes POCs

- by Flavius

Hi Please provide examples for all of these: XSS, CSRF, SQL injection with both the source code and the attack steps for each. Other attack vectors are welcome. The most complete answer gets a accepted. The configuration is a fairly standard one, as of PHP 5.3.2, core settings: allow_call_time_pass_reference => Off => Off allow_url_fopen => On => On allow_url_include => Off => Off always_populate_raw_post_data => Off => Off arg_separator.input => & => & arg_separator.output => & => & asp_tags => Off => Off auto_append_file => no value => no value auto_globals_jit => On => On auto_prepend_file => no value => no value browscap => no value => no value default_charset => no value => no value default_mimetype => text/html => text/html define_syslog_variables => Off => Off disable_classes => no value => no value disable_functions => no value => no value display_errors => STDOUT => STDOUT display_startup_errors => On => On doc_root => no value => no value docref_ext => no value => no value docref_root => no value => no value enable_dl => Off => Off error_append_string => no value => no value error_log => syslog => syslog error_prepend_string => no value => no value error_reporting => 32767 => 32767 exit_on_timeout => Off => Off expose_php => On => On extension_dir => /usr/lib/php/modules/ => /usr/lib/php/modules/ file_uploads => On => On highlight.bg => <font style="color: #FFFFFF">#FFFFFF</font> => <font style="color: #FFFFFF">#FFFFFF</font> highlight.comment => <font style="color: #FF8000">#FF8000</font> => <font style="color: #FF8000">#FF8000</font> highlight.default => <font style="color: #0000BB">#0000BB</font> => <font style="color: #0000BB">#0000BB</font> highlight.html => <font style="color: #000000">#000000</font> => <font style="color: #000000">#000000</font> highlight.keyword => <font style="color: #007700">#007700</font> => <font style="color: #007700">#007700</font> highlight.string => <font style="color: #DD0000">#DD0000</font> => <font style="color: #DD0000">#DD0000</font> html_errors => Off => Off ignore_repeated_errors => Off => Off ignore_repeated_source => Off => Off ignore_user_abort => Off => Off implicit_flush => On => On include_path => .:/usr/share/pear => .:/usr/share/pear log_errors => On => On log_errors_max_len => 1024 => 1024 magic_quotes_gpc => Off => Off magic_quotes_runtime => Off => Off magic_quotes_sybase => Off => Off mail.add_x_header => On => On mail.force_extra_parameters => no value => no value mail.log => no value => no value max_execution_time => 0 => 0 max_file_uploads => 20 => 20 max_input_nesting_level => 64 => 64 max_input_time => -1 => -1 memory_limit => 128M => 128M open_basedir => no value => no value output_buffering => 0 => 0 output_handler => no value => no value post_max_size => 8M => 8M precision => 14 => 14 realpath_cache_size => 16K => 16K realpath_cache_ttl => 120 => 120 register_argc_argv => On => On register_globals => Off => Off register_long_arrays => Off => Off report_memleaks => On => On report_zend_debug => Off => Off request_order => GP => GP safe_mode => Off => Off safe_mode_exec_dir => no value => no value safe_mode_gid => Off => Off safe_mode_include_dir => no value => no value sendmail_from => no value => no value sendmail_path => /usr/sbin/sendmail -t -i => /usr/sbin/sendmail -t -i serialize_precision => 100 => 100 short_open_tag => Off => Off SMTP => localhost => localhost smtp_port => 25 => 25 sql.safe_mode => Off => Off track_errors => Off => Off unserialize_callback_func => no value => no value upload_max_filesize => 2M => 2M upload_tmp_dir => no value => no value user_dir => no value => no value user_ini.cache_ttl => 300 => 300 user_ini.filename => .user.ini => .user.ini variables_order => GPCS => GPCS xmlrpc_error_number => 0 => 0 xmlrpc_errors => Off => Off y2k_compliance => On => On zend.enable_gc => On => On

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pagination for displaytag with colorbox in Spring framework

- by Hitesh Solanki

Hi..... I want to display the pop up for user selection using colorbox. I have put link on manageblacklist.jsp named 'select'. when I click on 'select' link ,colorbox is displayed. all user is displayed but pagination is not worked. I have used display tag for pagination. Without using colorbox, pagination is worked fine. I have used spring framework. The code of manageblacklist.jsp is given below: <%@ page contentType="text/html" pageEncoding="UTF-8" import="java.util.*"%> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <%@ include file="/WEB-INF/jsp/include.jsp" %> <%@ taglib prefix="form" uri="http://www.springframework.org/tags/form" %> <%@ taglib uri="http://displaytag.sf.net" prefix="display" %> <%@ page import="com.sufalam.mailserver.bean.User"%> <%@ page import="javax.servlet.http.HttpSession" %> <% String pageSize = (String) request.getAttribute("pageSize"); System.out.println("page size:" + pageSize); HttpSession session1 = request.getSession(); List<User> userList = (List<User>) session1.getAttribute("userList"); Iterator iterator = userList.iterator(); String user = (String) request.getAttribute("user"); System.out.println("user in the jsp :" + user); %> <html> <head> <script type="text/javascript" src="js/jquery142.js"></script> <script type="text/javascript" src="js/jquery.colorbox.js"></script> <link rel="stylesheet" href="style/colorbox.css" type="text/css"> <script type="text/javascript"> $(document).ready(function(){ //Examples of how to assign the ColorBox event to elements $(".example5").colorbox(); //Example of preserving a JavaScript event for inline calls. $("#click").click(function(){ $('#click').css({"background-color":"#f00", "color":"#fff", "cursor":"inherit"}).text("Open this window again and this message will still be here."); return false; }); }); </script> <script type="text/javascript"> function changePageSize() { var myValue = document.getElementById("combo1").value; document.getElementById("selectedPageSize").value=myValue; document.whitelistBlacklistForm.submit(); } function selectAll() { var selectAll = document.getElementById("checkAll"); var returnById = document.getElementsByName("check"); var i; var val; if (selectAll.checked == true) { val = true; } else { val = false; } for (i = 0; i < returnById.length; i++) { returnById[i].checked = val; } } function onload() { insertNavigation ('insertHereTop', 'insertHereBottom'); } function insertNavigation( topElementID, BottomElementID ) { if ( document.getElementById('pagingBanner') ){ document.getElementById(topElementID).innerHTML=document.getElementById('pagingBanner').innerHTML; document.getElementById(BottomElementID).innerHTML=document.getElementById('pagingBanner1').innerHTML; } } function confirmDelete() { if (confirm("Are you sure you want to delete selected records?")) { flag = 1; return true; } else { return false; } } function loadModels() { var flag=true; var textValue = document.getElementById('txtuser'); $.getJSON("ajaxblacklist.htm", // url { param :textValue.value }, // request params function(json) { // callback // var options = '<table class="displayTable" cellspacing="0"><thead><tr><th align = "center">Blacklisted Sender</th>'+ // '<th align ="center">Delete</th></tr></thead><tbody>'; var options = '<table width="100%" border="0" cellspacing="0" cellpadding="0"><tr><td style="background:url(images/leftbg.gif) repeat-y; width:8px;"></td>' + '<td class="middlesection"><table width="100%" border="0" cellspacing="0" cellpadding="0"><tr>' + '<td height="30" class="p10"><table width="100%" border="0" cellspacing="0" cellpadding="0" class="allboder" >' + '<tr><td class="tebelhd"> Blacklisted Sender </td></tr>'; for (i in json) { var state = json[i]; for(j in state){ var op = state[j]; if(op.length==undefined){ options += '<tr><td class="tdhd"><table width="0%" border="0" cellspacing="0" cellpadding="0"><tr><td width="741">'+ state[j].senderEmail + '</td><td align="center" width="148"><a href="managewhitelistblacklist.htm?sender='+state[j].senderEmail+'&recipient='+ state[j].recipientEmail+'&action=delete"><span> <img src="/MailServerV2/images/delete.gif"/> </span></a></td></tr></table></td></tr>'; break; } for(k in op) { if(flag == true) { flag = false; options += '<tr><td class="tdhd"><table width="0%" border="0" cellspacing="0" cellpadding="0"><tr>'; } else { flag = true; options += '<tr><td class="tdhd2"><table width="0%" border="0" cellspacing="0" cellpadding="0"><tr>'; } options += '<td width="741">'+ op[k].senderEmail +'</td><td align="center" width="148"><a href="managewhitelistblacklist.htm?sender='+op[k].senderEmail+'&recipient='+op[k].recipientEmail+'&action=delete"><span> <img src="/MailServerV2/images/delete.gif"/> </span></a></td></tr></table></td></tr>'; } } } options += '</td></tr></table>'; $("div[name^=blacklist]").html(options); }); } </script> </head> <body> <table width="" border="0" align="center" cellpadding="0" cellspacing="0" class="maintable"> <tr> <td class="topsection"><table width="100%" border="0" cellspacing="0" cellpadding="0"> <tr> <td valign="top" align="center" class="middlesection" ><table width="96%" border="0" cellspacing="0" cellpadding="0"> <tr> <td > </td> </tr> <tr> <td> <table width="100%" border="0" cellspacing ="0" cellpadding="0"> <tr> <td> <table width="100%" border="0" cellspacing="0" cellpadding="3"> <tr> <td align="left" valign="middle"><h1>Manage Blacklist</h1></td> <td align="right" valign="bottom"><div style="float:right;"><a href="savewhitelistblacklist.htm" class="buttonash"><span>Create Whitelist Blacklist </span></a></div></td> </tr> </table></td> </tr> <tr> <td class="bottomboder"><img src="images/ashish.gif" height="1" /></td> </tr> </table> </td> </tr> <tr> <td> </td> </tr> <tr> <td> </td> </tr> <tr> <td> <div id="TabbedPanels1" class="TabbedPanels"/> <div style="display: block;" class="TabbedPanelsContent"/> <div align="left" class="tebelhd"> Blacklist Information </div><div class="entry-edit"> <div class="fieldset" id="base_fieldset"> <div class="hor-scroll_1" align="left"> <fieldset Class="label1css" style="color:#666666"> <legend>Fields</legend> <table> <tr> <td align="right"> Recipient Email : </td> <td><input type="text" id="txtuser" name="txtuser" <% if (user != null) { %> value="<%=user%>" <% } else { %> value="" <% } %> /> </td> <td><a href="#" class="buttonash" onclick="loadModels()"><span>Search</span></a></td>  <td><a href="selectuser.htm" class="example5 buttonash" ><span>Select</span></a> </td> <td align="right"> </td> </tr> </table> </fieldset> <div id="blacklist" name="blacklist"></div> </div> </div> </div> </td> </tr> </table> </td> </tr> </table> </td>  <td style="background:url(images/rightbg.gif) repeat-y; width:8px;"></td> </tr> </table> <% // session1.removeAttribute("user"); %> </body> </html> So , please tell me how to work pagination .... Thanks in advanced...

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How do I send automated e-mails from Drupal using Messaging and Notifications?

- by Adrian

I am working on a Notifications plugin, and after starting to write my notes down about how to do this, decided to just post them here. Please feel free to come make modifications and changes. Eventually I hope to post this on the Drupal handbook as well. Thanks. --Adrian Sending automated e-mails from Drupal using Messaging and Notifications To implement a notifications plugin, you must implement the following functions: Use hook_messaging, hook_token_list and hook_token_values to create the messages that will be sent. Use hook_notifications to create the subscription types Add code to fire events (eg in hook_nodeapi) Add all UI elements to allow users to subscribe/unsubscribe Understanding Messaging The Messaging module is used to compose messages that can be delivered using various formats, such as simple mail, HTML mail, Twitter updates, etc. These formats are called "send methods." The backend details do not concern us here; what is important are the following concepts: TOKENS: tokens are provided by the "tokens" module. They allow you to write keywords in square brackets, [like-this], that can be replaced by any arbitrary value. Note: the token groups you create must match the keys you add to the $events-objects[$key] array. MESSAGE KEYS: A key is a part of a message, such as the greetings line. Keys can be different for each send method. For example, a plaintext mail's greeting might be "Hi, [user]," while an HTML greeing might be "Hi, [user]," and Twitter's might just be "[user-firstname]: ". Keys can have any arbitrary name. Keys are very simple and only have a machine-readable name and a user-readable description, the latter of which is only seen by admins. MESSAGE GROUPS: A group is a bunch of keys that often, but not always, might be used together to make up a complete message. For example, a generic group might include keys for a greeting, body, closing and footer. Groups can also be "subclassed" by selecting a "fallback" group that will supply any keys that are missing. Groups are also associated with modules; I'm not sure what these are used for. Understanding Notifications The Notifications module revolves around the following concepts: SUBSCRIPTIONS: Notifications plugins may define one or more types of subscriptions. For example, notifications_content defines subscriptions for: Threads (users are notified whenever a node or its comments change) Content types (users are notified whenever a node of a certain type is created or is changed) Users (users are notified whenever another user is changed) Subscriptions refer to both the user who's subscribed, how often they wish to be notified, the send method (for Messaging) and what's being subscribed to. This last part is defined in two steps. Firstly, a plugin defines several "subscription fields" (through a hook_notifications op of the same name), and secondly, "subscription types" (also an op) defines which fields apply to each type of subscription. For example, notifications_content defines the fields "nid," "author" and "type," and the subscriptions "thread" (nid), "nodetype" (type), "author" (author) and "typeauthor" (type and author), the latter referring to something like "any STORY by JOE." Fields are used to link events to subscriptions; an event must match all fields of a subscription (for all normal subscriptions) to be delivered to the recipient. The $subscriptions object is defined in subsequent sections. Notifications prefers that you don't create these objects yourself, preferring you to call the notifications_get_link() function to create a link that users may click on, but you can also use notifications_save_subscription and notifications_delete_subscription to do it yourself. EVENTS: An event is something that users may be notified about. Plugins create the $event object then call notifications_event($event). This either sends out notifications immediately, queues them to send out later, or both. Events include the type of thing that's changed (eg 'node', 'user'), the ID of the thing that's changed (eg $node-nid, $user-uid) and what's happened to it (eg 'create'). These are, respectively, $event-type, $event-oid (object ID) and $event-action. Warning: notifications_content_nodeapi also adds a $event-node field, referring to the node itself and not just $event-oid = $node-nid. This is not used anywhere in the core notifications module; however, when the $event is passed back to the 'query' op (see below), we assume the node is still present. Events do not refer to the user they will be referred to; instead, Notifications makes the connection between subscriptions and events, using the subscriptions' fields. MATCHING EVENTS TO SUBSCRIPTIONS: An event matches a subscription if it has the same type as the event (eg "node") and if the event matches all the correct fields. This second step is determined by the "query" hook op, which is called with the $event object as a parameter. The query op is responsible for giving Notifications a value for all the fields defined by the plugin. For example, notifications_content defines the 'nid', 'type' and 'author' fields, so its query op looks like this (ignore the case where $event_or_user = 'user' for now): $event_or_user = $arg0; $event_type = $arg1; $event_or_object = $arg2; if ($event_or_user == 'event' && $event_type == 'node' && ($node = $event_or_object->node) || $event_or_user == 'user' && $event_type == 'node' && ($node = $event_or_object)) { $query[]['fields'] = array( 'nid' => $node->nid, 'type' => $node->type, 'author' => $node->uid, ); return $query; After extracting the $node from the $event, we set $query[]['fields'] to a dictionary defining, for this event, all the fields defined by the module. As you can tell from the presence of the $query object, there's way more you can do with this op, but they are not covered here. DIGESTING AND DEDUPING: Understanding the relationship between Messaging and Notifications Usually, the name of a message group doesn't matter, but when being used with Notifications, the names must follow very strict patterns. Firstly, they must start with the name "notifications," and then are followed by either "event" or "digest," depending on whether the message group is being used to represent either a single event or a group of events. For 'events,' the third part of the name is the "type," which we get from Notification's $event-type (eg: notifications_content uses 'node'). The last part of the name is the operation being performed, which comes from Notification's $event-action. For example: notifications-event-node-comment might refer to the message group used when someone comments on a node notifications-event-user-update to a user who's updated their profile Hyphens cannot appear anywhere other than to separate the parts of these words. For 'digest' messages, the third and fourth part of the name come from hook_notification's "event types" callback, specifically this line: $types[] = array( 'type' => 'node', 'action' => 'insert', ... 'digest' => array('node', 'type'), ); $types[] = array( 'type' => 'node', 'action' => 'update', ... 'digest' => array('node', 'nid'), ); In this case, the first event type (node insertion) will be digested with the notifications-digest-node-type message template providing the header and footer, likely saying something like "the following [type] was created." The second event type (node update) will be digested with the notifications-digest-node-nid message template. Data Structure and Callback Reference $event The $event object has the following members: $event-type: The type of event. Must match the type in hook_notification::"event types". {notifications_event} $event-action: The action the event describes. Most events are sorted by [$event-type][$event-action]. {notifications_event}. $event-object[$object_type]: All objects relevant to the event. For example, $event-object['node'] might be the node that the event describes. $object_type can come from the 'event types' hook (see below). The main purpose appears to be to be passed to token_replace_multiple as the second parameter. $event-object[$event-type] is assumed to exist in the short digest processing functions, but this doesn't appear to be used anywhere. Not saved in the database; loaded by hook_notifications::"event load" $event-oid: apparently unused. The id of the primary object relevant to this event (eg the node's nid). $event-module: apparently unused $event-params[$key]: Mainly a place for plugins to save random data. The main module will serialize the contents of this array but does not use it in any way. However, notifications_ui appears to do something weird with it, possibly by using subscriptions' fields as keys into this array. I'm not sure why though. hook_notifications op 'subscription types': returns an array of subscription types provided by the plugin, in the form $key = array(...) with the following members: event_type: this subscription can only match events whose $event-type has this value. Stored in the database as notifications.event_type for every individual subscription. Apparently, this can be overiden in code but I wouldn't try it (see notifications_save_subscription). fields: an unkeyed array of fields that must be matched by an event (in addition to the event_type) for it to match this subscription. Each element of this array must be a key of the array returned by op 'subscription fields' which in turn must be used by op 'query' to actually perform the matching. title: user-readable title for their subscriptions page (eg the 'type' column in user/%uid/notifications/subscriptions) description: a user-readable description. page callback: used to add a supplementary page at user/%uid/notifications/blah. This and the following are used by notifications_ui as a part of hook_menu_alter. Appears to be partially deprecated. user page: user/%uid/notifications/blah. op 'event types': returns an array of event types, with each event type being an array with the following members: type: this will match $event-type action: this will match $event-action digest: an array with two ordered (non-keyed) elements, "type" and "field." 'type' is used as an index into $event-objects. 'field' is also used to group events like so: $event-objects[$type]-$field. For example, 'field' might be 'nid' - if the object is a node, the digest lines will be grouped by node ID. Finally, both are used to find the correct Messaging template; see discussion above. description: used on the admin "Notifications-Events" page name: unused, use Messaging instead line: deprecated, use Messaging instead Other Stuff This is an example of the main query that inserts an event into the queue: INSERT INTO {notifications_queue} (uid, destination, sid, module, eid, send_interval, send_method, cron, created, conditions) SELECT DISTINCT s.uid, s.destination, s.sid, s.module, %d, // event ID s.send_interval, s.send_method, s.cron, %d, // time of the event s.conditions FROM {notifications} s INNER JOIN {notifications_fields} f ON s.sid = f.sid WHERE (s.status = 1) AND (s.event_type = '%s') // subscription type AND (s.send_interval >= 0) AND (s.uid <> %d) AND ( (f.field = '%s' AND f.intval IN (%d)) // everything from 'query' op OR (f.field = '%s' AND f.intval = %d) OR (f.field = '%s' AND f.value = '%s') OR (f.field = '%s' AND f.intval = %d)) GROUP BY s.uid, s.destination, s.sid, s.module, s.send_interval, s.send_method, s.cron, s.conditions HAVING s.conditions = count(f.sid)

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