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  • Issues querying Access '07 database in C#

    - by Kye
    I'm doing a .NET unit as part of my studies. I've only just started, with a lecturer that as kinda failed to give me the most solid foundation with .NET, so excuse the noobishness. I'm making a pretty simple and generic database-driven application. I'm using C# and I'm accessing a Microsoft Access 2007 database. I've put the database-ish stuff in its own class with the methods just spitting out OleDbDataAdapters that I use for committing. I feed any methods which preform a query a DataSet object from the main program, which is where I'm keeping the data (multiple tables in the db). I've made a very generic private method that I use to perform SQL SELECT queries and have some public methods wrapping that method to get products, orders.etc (it's a generic retail database). The generic method uses a separate Connect method to actually make the connection, and it is as follows: private static OleDbConnection Connect() { OleDbConnection conn = new OleDbConnection( @"Provider=Microsoft.ACE.OLEDB.12.0; Data Source=C:\Temp\db.accdb"); return conn; } The generic method is as follows: private static OleDbDataAdapter GenericSelectQuery( DataSet ds, string namedTable, String selectString) { OleDbCommand oleCommand = new OleDbCommand(); OleDbConnection conn = Connect(); oleCommand.CommandText = selectString; oleCommand.Connection = conn; oleCommand.CommandType = CommandType.Text; OleDbDataAdapter adapter = new OleDbDataAdapter(); adapter.SelectCommand = oleCommand; adapter.MissingSchemaAction = MissingSchemaAction.AddWithKey; adapter.Fill(ds, namedTable); return adapter; } The wrapper methods just pass along the DataSet that they received from the main program, the namedtable string is the name of the table in the dataset, and you pass in the query you wish to make. It doesn't matter which query I give it (even something simple like SELECT * FROM TableName) I still get thrown an OleDbException, stating that there was en error with the FROM clause of the query. I've just resorted to building the queries with Access, but there's still no use. Obviously there's something wrong with my code, which wouldn't actually surprise me. Here are some wrapper methods I'm using. public static OleDbDataAdapter GetOrderLines(DataSet ds) { OleDbDataAdapter adapter = GenericSelectQuery( ds, "orderlines", "SELECT OrderLine.* FROM OrderLine;"); return adapter; } They all look the same, it's just the SQL that changes.

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  • Why C# is not statically typed but F# and Haskell are?

    - by ??????? ???????
    There was a talk given by Brian Hurt about advantages and disadvantages of static typing. Brian said that by static typing he don't mean C#, but F# and Haskell. Is it because of dynamic keyword added to C#-4.0? But this feature is relatively rarely useful. By the way, there are ? and unsafeCoerse in Haskell which obviously are not the same, but something that could blown your head off in runtime similarly like exception thrown as a result of dynamic. Finally, why F# and Haskell could be named a statically typed languages and C# couldn't?

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  • Apress Deal of the day - 5/Feb/2011

    - by TATWORTH
    Today's $10 Deal of the Day from Apress at http://www.apress.com/info/dailydeal is: Pro ASP.NET 4 in C# 2010, Fourth Edition ASP.NET 4 is the latest version of Microsoft's revolutionary ASP.NET technology. It is the principal standard for creating dynamic web pages on the Windows platform. Pro ASP.NET 4 in C# 2010 raises the bar for high-quality, practical advice on learning and deploying Microsoft's dynamic web solution. $59.99 | Published Jun 2010 | Matthew MacDonald I am reviewing this book at the moment but I was already sufficiently impressed by this book to have bought the PDF the day it was available last December.

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  • Cannot boot Windows 7 after installing Ubuntu 13.04

    - by whowantsakookie
    So I boot up my computer after installing Ubuntu 13.04. Grub correctly shows me all available boot options and I am able to boot to Ubuntu. However, when I try to boot into Windows 7, grub hangs at a purple screen. I have an HP laptop. It came with all four primary partitions taken up by the Windows bootloader, the actual Windows partition, one called HP_TOOLS, and another for HP Restore. I was able to back up and delete HP_TOOLS and the recovery partition, and change my disk type from Dynamic to Basic (GParted doesn't recognize Dynamic drives). I then booted into a live session of Ubuntu and made two partitions with GParted: one large partition for storage space that I could use between the two operating systems (sda4), and another extended partition (sda3) which contained Ubuntu (sda6) and it's swap space (sda5). It currently looks like this: I'm not sure if the second paragraph is actually relevant, I just want you to know all the variables in the equation. Thank you in advance for helping this poor noob.

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  • HTML5, PHP, JAVA or asp?

    - by user67418
    I am building a new website for a friend of mine. Its all plain html, and a server side include. The problem is to build static pages for 500 products would not be fun to create, or maintain. So i am forced to at least put dynamic information on these pages based off a spreadsheet, or dynamic pages all together. What i want to do is have a spreadsheet that can be used to keep track of in stock quantity, sku numbers, ecc.. that way i dont have to update hundreds of pages every night. He can just edit the spreadsheet and the pages will automatically adjust. I am a busy man, and i am not asking anyone to just give me the answer. But to save some time what is more worth learning to get this done fastest. HTML5, PHP, JAVA asp, or is there somehthing else better suited?

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  • Unable to apt-get upgrade in ubuntu 11.10

    - by blackhole
    These are the errors shows by different client Update Manager: Traceback (most recent call last): File "/usr/lib/python2.7/dist-packages/aptdaemon/worker.py", line 968, in simulate trans.unauthenticated = self._simulate_helper(trans) File "/usr/lib/python2.7/dist-packages/aptdaemon/worker.py", line 1092, in _simulate_helper return depends, self._cache.required_download, \ File "/usr/lib/python2.7/dist-packages/apt/cache.py", line 235, in required_download pm.get_archives(fetcher, self._list, self._records) SystemError: E:Method has died unexpectedly!, E:Sub-process returned an error code (100), E:Method /usr/lib/apt/methods/ did not start correctly Synaptic package Manager E: Method has died unexpectedly! E: Sub-process returned an error code (100) E: Method /usr/lib/apt/methods/ did not start correctly E: Unable to lock the download directory Command: sudo apt-get upgrade Reading package lists... Done Building dependency tree Reading state information... Done The following packages will be upgraded: libfreetype6 libfreetype6-dev 2 upgraded, 0 newly installed, 0 to remove and 0 not upgraded. Failed to exec method /usr/lib/apt/methods/ E: Method has died unexpectedly! E: Sub-process returned an error code (100) E: Method /usr/lib/apt/methods/ did not start correctly Can anyone one tell me how to resolve these issues ? I have no volatile packages or anything so i am even posting the preview of my sources.list file. # deb cdrom:[Ubuntu 10.10 _Maverick Meerkat_ - Release i386 (20101007)]/ maverick main restricted # See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to # newer versions of the distribution. deb http://in.archive.ubuntu.com/ubuntu/ oneiric main restricted ## Major bug fix updates produced after the final release of the ## distribution. deb http://in.archive.ubuntu.com/ubuntu/ oneiric-updates main restricted ## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu ## team. Also, please note that software in universe WILL NOT receive any ## review or updates from the Ubuntu security team. deb http://in.archive.ubuntu.com/ubuntu/ oneiric universe deb http://in.archive.ubuntu.com/ubuntu/ oneiric-updates universe ## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu ## team, and may not be under a free licence. Please satisfy yourself as to ## your rights to use the software. Also, please note that software in ## multiverse WILL NOT receive any review or updates from the Ubuntu ## security team. deb http://in.archive.ubuntu.com/ubuntu/ oneiric multiverse deb http://in.archive.ubuntu.com/ubuntu/ oneiric-updates multiverse ## Uncomment the following two lines to add software from the 'backports' ## repository. ## N.B. software from this repository may not have been tested as ## extensively as that contained in the main release, although it includes ## newer versions of some applications which may provide useful features. ## Also, please note that software in backports WILL NOT receive any review ## or updates from the Ubuntu security team. # deb http://in.archive.ubuntu.com/ubuntu/ maverick-backports main restricted universe multiverse # deb-src http://in.archive.ubuntu.com/ubuntu/ maverick-backports main restricted universe multiverse ## Uncomment the following two lines to add software from Canonical's ## 'partner' repository. ## This software is not part of Ubuntu, but is offered by Canonical and the ## respective vendors as a service to Ubuntu users. deb http://archive.canonical.com/ubuntu oneiric partner deb-src http://archive.canonical.com/ubuntu oneiric partner ## This software is not part of Ubuntu, but is offered by third-party ## developers who want to ship their latest software. deb http://extras.ubuntu.com/ubuntu oneiric main deb-src http://extras.ubuntu.com/ubuntu oneiric main deb http://in.archive.ubuntu.com/ubuntu/ oneiric-security main restricted deb http://in.archive.ubuntu.com/ubuntu/ oneiric-security universe deb http://in.archive.ubuntu.com/ubuntu/ oneiric-security multiverse # deb http://archive.canonical.com/ lucid partner Here is the preview of my sources.list file

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  • [EF + Oracle] Entities

    - by JTorrecilla
    Prologue Following with the Serie I started yesterday about Entity Framework with Oracle, Today I am going to start talking about Entities. What is an Entity? A Entity is an object of the EF model corresponding to a record in a DB table. For example, let’s see, in Image 1 we can see one Entity from our model, and in the second one we can see the mapping done with the DB. (Image 1) (Image 2) More in depth a Entity is a Class inherited from the abstract class “EntityObject”, contained by the “System.Data.Objects.DataClasses” namespace. At the same time, this class inherits from the following Class and interfaces: StructuralObject: It is an Abstract class that inherits from INotifyPropertyChanging and INotifyPropertyChanged interfaces, and it exposes the events that manage the Changes of the class, and the functions related to check the data types of the Properties from our Entity.  IEntityWithKey: Interface which exposes the Key of the entity. IEntityWithChangeTracker: Interface which lets indicate the state of the entity (Detached, Modified, Added…) IEntityWithRelationships: Interface which indicates the relations about the entity. Which is the Content of a Entity? A Entity is composed by: Properties, Navigation Properties and Methods. What is a Property? A Entity Property is an object that represents a column from the mapped table from DB. It has a data type equivalent in .Net Framework to the DB Type. When we create the EF model, VS, internally, create the code for each Entity selected in the Tables step, such all methods that we will see in next steps. For each property, VS creates a structure similar to: · Private variable with the mapped Data type. · Function with a name like On{Property_Name}Changing({dataType} value): It manages the event which happens when we try to change the value. · Function with a name like On{Property_Name}Change: It manages the event raised when the property has changed successfully. · Property with Get and Set methods: The Set Method manages the private variable and do the following steps: Raise Changing event. Report the Entity is Changing. Set the prívate variable. For it, Use the SetValidValue function of the StructuralObject. There is a function for each datatype, and the functions takes 2 params: the value, and if the prop allow nulls. Invoke that the entity has been successfully changed. Invoke the Changed event of the Prop. ReportPropertyChanging and ReportPropertyChanged events, let, respectively, indicate that there is pending changes in the Entity, and the changes have success correctly. While the ReportPropertyChanged is raised, the Track State of the Entity will be changed. What is a Navigation Property? Navigation Properties are a kind of property of the type: EntityCollection<TEntity>, where TEntity is an Entity type from the model related with the current one, it is said, is a set of record from a related table in the DB. The EntityCollection class inherits from: · RelatedEnd: There is an abstract class that give the functions needed to obtein the related objects. · ICollection<TEntity> · IEnumerable<TEntity> · IEnumerable · IListSource For the previous interfaces, I wish recommend the following post from Jose Miguel Torres. Navigation properties allow us, to get and query easily objects related with the Entity. Methods? There is only one method in the Entity object. “Create{Entity}”, that allow us to create an object of the Entity by sending the parameters needed to create it. Finally After this chapter, we know what is an Entity, how is related to the DB and the relation to other Entities. In following chapters, we will se CRUD operations(Create, Read, Update, Delete).

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  • Automated SSRS deployment with the RS utility

    - by Stacy Vicknair
    If you’re familiar with SSRS and development you are probably aware of the SSRS web services. The RS utility is a tool that comes with SSRS that allows for scripts to be executed against against the SSRS web service without needing to create an application to consume the service. One of the better benefits of using this format rather than writing an application is that the script can be modified by others who might be involved in the creation and addition of scripts or management of the SSRS environment.   Reporting Services Scripter Jasper Smith from http://www.sqldbatips.com created Reporting Services Scripter to assist with the created of a batch process to deploy an entire SSRS environment. The helper scripts below were created through the modification of his generated scripts. Why not just use this tool? You certainly can. For me, the volume of scripts generated seems less maintainable than just using some common methods extracted from these scripts and creating a deployment in a single script file. I would, however, recommend this as a product if you do not think that your environment will change drastically or if you do not need to deploy with a higher level of control over the deployment. If you just need to replicate, this tool works great. Executing with RS.exe Executing a script against rs.exe is fairly simple. The Script Half the battle is having a starting point. For the scripting I needed to do the below is the starter script. A few notes: This script assumes integrated security. This script assumes your reports have one data source each. Both of the above are just what made sense for my scenario and are definitely modifiable to accommodate your needs. If you are unsure how to change the scripts to your needs, I recommend Reporting Services Scripter to help you understand how the differences. The script has three main methods: CreateFolder, CreateDataSource and CreateReport. Scripting the server deployment is just a process of recreating all of the elements that you need through calls to these methods. If there are additional elements that you need to deploy that aren’t covered by these methods, again I suggest using Reporting Services Scripter to get the code you would need, convert it to a repeatable method and add it to this script! Public Sub Main() CreateFolder("/", "Data Sources") CreateFolder("/", "My Reports") CreateDataSource("/Data Sources", "myDataSource", _ "Data Source=server\instance;Initial Catalog=myDatabase") CreateReport("/My Reports", _ "MyReport", _ "C:\myreport.rdl", _ True, _ "/Data Sources", _ "myDataSource") End Sub   Public Sub CreateFolder(parent As String, name As String) Dim fullpath As String = GetFullPath(parent, name) Try RS.CreateFolder(name, parent, GetCommonProperties()) Console.WriteLine("Folder created: {0}", name) Catch e As SoapException If e.Detail.Item("ErrorCode").InnerText = "rsItemAlreadyExists" Then Console.WriteLine("Folder {0} already exists and cannot be overwritten", fullpath) Else Console.WriteLine("Error : " + e.Detail.Item("ErrorCode").InnerText + " (" + e.Detail.Item("Message").InnerText + ")") End If End Try End Sub   Public Sub CreateDataSource(parent As String, name As String, connectionString As String) Try RS.CreateDataSource(name, parent,False, GetDataSourceDefinition(connectionString), GetCommonProperties()) Console.WriteLine("DataSource {0} created successfully", name) Catch e As SoapException Console.WriteLine("Error : " + e.Detail.Item("ErrorCode").InnerText + " (" + e.Detail.Item("Message").InnerText + ")") End Try End Sub   Public Sub CreateReport(parent As String, name As String, location As String, overwrite As Boolean, dataSourcePath As String, dataSourceName As String) Dim reportContents As Byte() = Nothing Dim warnings As Warning() = Nothing Dim fullpath As String = GetFullPath(parent, name)   'Read RDL definition from disk Try Dim stream As FileStream = File.OpenRead(location) reportContents = New [Byte](stream.Length-1) {} stream.Read(reportContents, 0, CInt(stream.Length)) stream.Close()   warnings = RS.CreateReport(name, parent, overwrite, reportContents, GetCommonProperties())   If Not (warnings Is Nothing) Then Dim warning As Warning For Each warning In warnings Console.WriteLine(Warning.Message) Next warning Else Console.WriteLine("Report: {0} published successfully with no warnings", name) End If   'Set report DataSource references Dim dataSources(0) As DataSource   Dim dsr0 As New DataSourceReference dsr0.Reference = dataSourcePath Dim ds0 As New DataSource ds0.Item = CType(dsr0, DataSourceDefinitionOrReference) ds0.Name=dataSourceName dataSources(0) = ds0     RS.SetItemDataSources(fullpath, dataSources)   Console.Writeline("Report DataSources set successfully")       Catch e As IOException Console.WriteLine(e.Message) Catch e As SoapException Console.WriteLine("Error : " + e.Detail.Item("ErrorCode").InnerText + " (" + e.Detail.Item("Message").InnerText + ")") End Try End Sub     Public Function GetCommonProperties() As [Property]() 'Common CatalogItem properties Dim descprop As New [Property] descprop.Name = "Description" descprop.Value = "" Dim hiddenprop As New [Property] hiddenprop.Name = "Hidden" hiddenprop.Value = "False"   Dim props(1) As [Property] props(0) = descprop props(1) = hiddenprop Return props End Function   Public Function GetDataSourceDefinition(connectionString as String) Dim definition As New DataSourceDefinition definition.CredentialRetrieval = CredentialRetrievalEnum.Integrated definition.ConnectString = connectionString definition.Enabled = True definition.EnabledSpecified = True definition.Extension = "SQL" definition.ImpersonateUser = False definition.ImpersonateUserSpecified = True definition.Prompt = "Enter a user name and password to access the data source:" definition.WindowsCredentials = False definition.OriginalConnectStringExpressionBased = False definition.UseOriginalConnectString = False Return definition End Function   Private Function GetFullPath(parent As String, name As String) As String If parent = "/" Then Return parent + name Else Return parent + "/" + name End If End Function

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  • SQL Azure: Notes on Building a Shard Technology

    - by Herve Roggero
    In Chapter 10 of the book on SQL Azure (http://www.apress.com/book/view/9781430229612) I am co-authoring, I am digging deeper in what it takes to write a Shard. It's actually a pretty cool exercise, and I wanted to share some thoughts on how I am designing the technology. A Shard is a technology that spreads the load of database requests over multiple databases, as transparently as possible. The type of shard I am building is called a Vertical Partition Shard  (VPS). A VPS is a mechanism by which the data is stored in one or more databases behind the scenes, but your code has no idea at design time which data is in which database. It's like having a mini cloud for records instead of services. Imagine you have three SQL Azure databases that have the same schema (DB1, DB2 and DB3), you would like to issue a SELECT * FROM Users on all three databases, concatenate the results into a single resultset, and order by last name. Imagine you want to ensure your code doesn't need to change if you add a new database to the shard (DB4). Now imagine that you want to make sure all three databases are queried at the same time, in a multi-threaded manner so your code doesn't have to wait for three database calls sequentially. Then, imagine you would like to obtain a breadcrumb (in the form of a new, virtual column) that gives you a hint as to which database a record came from, so that you could update it if needed. Now imagine all that is done through the standard SqlClient library... and you have the Shard I am currently building. Here are some lessons learned and techniques I am using with this shard: Parellel Processing: Querying databases in parallel is not too hard using the Task Parallel Library; all you need is to lock your resources when needed Deleting/Updating Data: That's not too bad either as long as you have a breadcrumb. However it becomes more difficult if you need to update a single record and you don't know in which database it is. Inserting Data: I am using a round-robin approach in which each new insert request is directed to the next database in the shard. Not sure how to deal with Bulk Loads just yet... Shard Databases:  I use a static collection of SqlConnection objects which needs to be loaded once; from there on all the Shard commands use this collection Extension Methods: In order to make it look like the Shard commands are part of the SqlClient class I use extension methods. For example I added ExecuteShardQuery and ExecuteShardNonQuery methods to SqlClient. Exceptions: Capturing exceptions in a multi-threaded code is interesting... but I kept it simple for now. I am using the ConcurrentQueue to store my exceptions. Database GUID: Every database in the shard is given a GUID, which is calculated based on the connection string's values. DataTable. The Shard methods return a DataTable object which can be bound to objects.  I will be sharing the code soon as an open-source project in CodePlex. Please stay tuned on twitter to know when it will be available (@hroggero). Or check www.bluesyntax.net for updates on the shard. Thanks!

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  • Browser Specific Extensions of HttpClient

    - by imran_ku07
            Introduction:                     REpresentational State Transfer (REST) causing/leaving a great impact on service/API development because it offers a way to access a service without requiring any specific library by embracing HTTP and its features. ASP.NET Web API makes it very easy to quickly build RESTful HTTP services. These HTTP services can be consumed by a variety of clients including browsers, devices, machines, etc. With .NET Framework 4.5, we can use HttpClient class to consume/send/receive RESTful HTTP services(for .NET Framework 4.0, HttpClient class is shipped as part of ASP.NET Web API). The HttpClient class provides a bunch of helper methods(for example, DeleteAsync, PostAsync, GetStringAsync, etc.) to consume a HTTP service very easily. ASP.NET Web API added some more extension methods(for example, PutAsJsonAsync, PutAsXmlAsync, etc) into HttpClient class to further simplify the usage. In addition, HttpClient is also an ideal choice for writing integration test for a RESTful HTTP service. Since a browser is a main client of any RESTful API, it is also important to test the HTTP service on a variety of browsers. RESTful service embraces HTTP headers and different browsers send different HTTP headers. So, I have created a package that will add overloads(with an additional Browser parameter) for almost all the helper methods of HttpClient class. In this article, I will show you how to use this package.           Description:                     Create/open your test project and install ImranB.SystemNetHttp.HttpClientExtensions NuGet package. Then, add this using statement on your class, using ImranB.SystemNetHttp;                     Then, you can start using any HttpClient helper method which include the additional Browser parameter. For example,  var client = new HttpClient(myserver); var task = client.GetAsync("http://domain/myapi", Browser.Chrome); task.Wait(); var response = task.Result; .                     Here is the definition  of Browser, public enum Browser { Firefox = 0, Chrome = 1, IE10 = 2, IE9 = 3, IE8 = 4, IE7 = 5, IE6 = 6, Safari = 7, Opera = 8, Maxthon = 9, }                     These extension methods will make it very easy to write browser specific integration test. It will also help HTTP service consumer to mimic the request sending behavior of a browser. This package source is available on github. So, you can grab the source and add some additional behavior on the top of these extensions.         Summary:                     Testing a REST API is an important aspect of service development and today, testing with a browser is crucial. In this article, I showed how to write integration test that will mimic the browser request sending behavior. I also showed an example. Hopefully you will enjoy this article too.

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  • Flow-Design Cheat Sheet &ndash; Part II, Translation

    - by Ralf Westphal
    In my previous post I summarized the notation for Flow-Design (FD) diagrams. Now is the time to show you how to translate those diagrams into code. Hopefully you feel how different this is from UML. UML leaves you alone with your sequence diagram or component diagram or activity diagram. They leave it to you how to translate your elaborate design into code. Or maybe UML thinks it´s so easy no further explanations are needed? I don´t know. I just know that, as soon as people stop designing with UML and start coding, things end up to be very different from the design. And that´s bad. That degrades graphical designs to just time waste on paper (or some designer). I even believe that´s the reason why most programmers view textual source code as the only and single source of truth. Design and code usually do not match. FD is trying to change that. It wants to make true design a first class method in every developers toolchest. For that the first prerequisite is to be able to easily translate any design into code. Mechanically, without thinking. Even a compiler could do it :-) (More of that in some other article.) Translating to Methods The first translation I want to show you is for small designs. When you start using FD you should translate your diagrams like this. Functional units become methods. That´s it. An input-pin becomes a method parameter, an output-pin becomes a return value: The above is a part. But a board can be translated likewise and calls the nested FUs in order: In any case be sure to keep the board method clear of any and all business logic. It should not contain any control structures like if, switch, or a loop. Boards do just one thing: calling nested functional units in proper sequence. What about multiple input-pins? Try to avoid them. Replace them with a join returning a tuple: What about multiple output-pins? Try to avoid them. Or return a tuple. Or use out-parameters: But as I said, this simple translation is for simple designs only. Splits and joins are easily done with method translation: All pretty straightforward, isn´t it. But what about wires, named pins, entry points, explicit dependencies? I suggest you don´t use this kind of translation when your designs need these features. Translating to methods is for small scale designs like you might do once you´re working on the implementation of a part of a larger design. Or maybe for a code kata you´re doing in your local coding dojo. Instead of doing TDD try doing FD and translate your design into methods. You´ll see that way it´s much easier to work collaboratively on designs, remember them more easily, keep them clean, and lessen the need for refactoring. Translating to Events [coming soon]

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  • Doubts about several best practices for rest api + service layer

    - by TheBeefMightBeTough
    I'm going to be starting a project soon that exposes a restful api for business intelligence. It may not be limited to a restful api, so I plan to delegate requests to a service layer that then coordinates multiple domain objects (each of which have business logic local to the object). The api will likely have many calls as it is a long-term project. While thinking about the design, I recalled a few best practices. 1) Use command objects at the controller layer (I'm using Spring MVC). 2) Use DTOs at the service layer. 3) Validate in both the controller and service layer, though for different reasons. I have my doubts about these recommendations. 1) Using command objects adds a lot of extra single-purpose classes (potentially one per request). What exactly is the benefit? Annotation based validation can be done using this approach, sure. What if I have two requests that take the same parameters, but have different validation requirements? I would have to have two different classes with exactly the same members but different annotations? Bleh. 2) I have heard that using DTOs is preferable to parameters because it makes for more maintainable code down the road (say, e.g., requirements change and the service parameters need to be altered). I don't quite understand this. Shouldn't an api be more-or-less set in stone? I would understand that in the early phases of a project (or, especially, an entire company) the domain itself will not be well understood, and thus core domain objects may change along with the apis that manipulate these objects. At this point however the number of api methods should be small and their dependents few, so changes to the methods could easily be tolerated from a maintainability standpoint. In a large api with many methods and a substantial domain model, I would think having a DTO for potentially each domain object would become unwieldy. Am I misunderstanding something here? 3) I see validation in the controller and service layer as redundant in most cases. Why would I validate that parameters are not null and are in general well formed in the controller if the service is going to do exactly the same (and more). Couldn't I just do all the validation in the service and throw a runtime exception with a list of bad parameters then catch that in the controller to make the error messages more presentable? Better yet, couldn't I just make the error messages user-friendly in the service and let the exception trickle up to a global handler (ControllerAdvice in spring, for example)? Is there something wrong with either of these approaches? (I do see a use case for controller validation if the input does not map one-to-one with the service input, but since the controllers are for a rest api and not forms, the api parameters will probably map directly to service parameters.) I do also have a question about unchecked vs checked exceptions. Namely, I'm not really sure why I'd ever want to use a checked exception. Every time I have seen them used they just get wrapped into general exceptions (DomainException, SystemException, ApplicationException, w/e) to reduce the signature length of methods, or devs catch Exception rather than dealing with the App1Exception, App2Exception, Sys1Exception, Sys2Exception. I don't see how either of these practices is very useful. Why not just use unchecked exceptions always and catch the ones you actually do care about? You could just document what unchecked exceptions the method throws.

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  • Profiling Startup Of VS2012 &ndash; dotTrace Profiler

    - by Alois Kraus
    Jetbrains which is famous for the Resharper tool has also a profiler in its portfolio. I downloaded dotTrace 5.2 Professional (569€+VAT) to check how far I can profile the startup of VS2012. The most interesting startup option is “.NET Process”. With that you can profile the next started .NET process which is very useful if you want to profile an application which is not started by you.     I did select Tracing as and Wall time to get similar options across all profilers. For some reason the attach option did not work with .NET 4.5 on my home machine. But I am sure that it did work with .NET 4.0 some time ago. Since we are profiling devenv.exe we can also select “Standalone Application” and start it from the profiler. The startup time of VS does increase about a factor 3 but that is ok. You get mainly three windows to work with. The first one shows the threads where you can drill down thread wise where most time is spent. I The next window is the call tree which does merge all threads together in a similar view. The last and most useful view in my opinion is the Plain List window which is nearly the same as the Method Grid in Ants Profiler. But this time we do get when I enable the Show system functions checkbox not a 150 but 19407 methods to choose from! I really tried with Ants Profiler to find something about out how VS does work but look how much we were missing! When I double click on a method I do get in the lower pane the called methods and their respective timings. This is something really useful and I can nicely drill down to the most important stuff. The measured time seems to be Wall Clock time which is a good thing to see where my time is really spent. You can also use Sampling as profiling method but this does give you much less information. Except for getting a first idea where to look first this profiling mode is not very useful to understand how you system does interact.   The options have a good list of presets to hide by default many method and gray them out to concentrate on your code. It does not filter anything out if you enable Show system functions. By default methods from these assemblies are hidden or if the checkbox is checked grayed out. All in all JetBrains has made a nice profiler which does show great detail and it has nice drill down capabilities. The only thing is that I do not trust its measured timings. I did fall several times into the trap with this one to optimize at places which were already fast but the profiler did show high times in these methods. After measuring with Tracing I was certain that the measured times were greatly exaggerated. Especially when IO is involved it seems to have a hard time to subtract its own overhead. What I did miss most was the possibility to profile not only the next started process but to be able to select a process by name and perhaps a count to profile the next n processes of this name. Next: YourKit

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  • Identity in .NET 4.5&ndash;Part 3: (Breaking) changes

    - by Your DisplayName here!
    I recently started porting a private build of Thinktecture.IdentityModel to .NET 4.5 and noticed a number of changes. The good news is that I can delete large parts of my library because many features are now in the box. Along the way I found some other nice additions. ClaimsIdentity now has methods to query the claims collection, e.g. HasClaim(), FindFirst(), FindAll(). ClaimsPrincipal has those methods as well. But they work across all contained identities. Nice! ClaimsPrincipal.Current retrieves the ClaimsPrincipal from Thread.CurrentPrincipal. Combined with the above changes, no casting necessary anymore. SecurityTokenHandler now has read and write methods that work directly with strings. This makes it much easier to deal with non-XML tokens like SWT or JWT. A new session security token handler that uses the ASP.NET machine key to protect the cookie. This makes it easier to get started in web farm scenarios. No need for a custom service host factory or the federation behavior anymore. WCF can be switched into “WIF mode” with the useIdentityConfiguration switch (odd name though). Tooling has become better and the new test STS makes it very easy to get started. On the other hand – and that was kind of expected – to bring claims into the core framework, there are also some breaking changes for WIF code. If you want to migrate (and I would recommend that), most changes to your code are mechanical. The following is a brain dump of the changes I encountered. Assembly Microsoft.IdentityModel is gone. The new functionality is now in mscorlib, System.IdentityModel(.Services) and System.ServiceModel. All the namespaces have changed as well. No IClaimsPrincipal and IClaimsIdentity anymore. Configuration section has been split into <system.identityModel /> and <system.identityModel.services />. WCF configuration story has changed as well. Claim.ClaimType is now Claim.Type. ClaimCollection is now IEnumerable<Claim>. IsSessionMode is now IsReferenceMode. Bootstrap token handling is different now. ClaimsPrincipalHttpModule is gone. This is not really needed anymore, apart from maybe claims transformation (see here). Various factory methods on ClaimsPrincipal are gone (e.g. ClaimsPrincipal.CreateFromIdentity()). SecurityTokenHandler.ValidateToken now returns a ReadOnlyCollection<ClaimsIdentity>. Some lower level helper classes are gone or internal now (e.g. KeyGenerator). The WCF WS-Trust bindings are gone. I think this is a pity. They were *really* useful when doing work with WSTrustChannelFactory. Since WIF is part of the Windows operating system and also supported in future versions of .NET, there is no urgent need to migrate to the 4.5 claims model. But obviously, going forward, at some point you want to make the move.

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  • How to build glibc 2.11.2 on RHEL5?

    - by netvope
    Using gcc-4.4.4 or 4.5.0, I'm unable to make glibc-2.11.2 on RHEL 5.5: .././scripts/mkinstalldirs /dev/shm/glibc-2.11.2-build/sunrpc/rpcsvc CPP='gcc -B/home/klaw/share/rhel5/ -E -x c-header' /dev/shm/glibc-2.11.2-build/elf/ld-linux-x86-64.so.2 --library-path /dev/shm/glibc-2.11.2-build:/dev/shm/glibc-2.11.2-build/math:/dev/shm/glibc-2.11.2-build/elf:/dev/shm/glibc-2.11.2-build/dlfcn:/dev/shm/glibc-2.11.2-build/nss:/dev/shm/glibc-2.11.2-build/nis:/dev/shm/glibc-2.11.2-build/rt:/dev/shm/glibc-2.11.2-build/resolv:/dev/shm/glibc-2.11.2-build/crypt:/dev/shm/glibc-2.11.2-build/nptl /dev/shm/glibc-2.11.2-build/sunrpc/rpcgen -Y ../scripts -c rpcsvc/bootparam_prot.x -o /dev/shm/glibc-2.11.2-build/sunrpc/xbootparam_prot.T Inconsistency detected by ld.so: dynamic-link.h: 209: elf_get_dynamic_info: Assertion `info[15] == ((void *)0)' failed! make[2]: *** [/dev/shm/glibc-2.11.2-build/sunrpc/xnlm_prot.stmp] Error 127 make[2]: Leaving directory `/dev/shm/glibc-2.11.2/sunrpc' make[1]: *** [sunrpc/others] Error 2 make[1]: Leaving directory `/dev/shm/glibc-2.11.2' make: *** [all] Error 2 The error comes from the ld.so made by glibc: $ elf/ld.so Inconsistency detected by ld.so: dynamic-link.h: 209: elf_get_dynamic_info: Assertion `info[15] == ((void *)0)' failed! $ I got similar error with glibc-2.11.1 (only the line number of dynamic-link.h is different). Any ideas how I can fix this? gcc-4.4.4 and 4.5.0 were compiled with: binutils-2.20.1 gmp-5.0.1 mpc-0.8.2 mpfr-2.4.2

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  • Changes made to cli's php.ini not taking effect

    - by Sandeepan Nath
    I have two php.ini files - /etc/php.ini which loads in case of cli /opt/lampp/etc/php.ini which loads in case of browser. I am able to use PHP's Mailparse extension after adding the line extension=mailparse.so in the /opt/lampp/etc/php.ini and restarting lampp. But I am not able to load the same in case of command line - getting PHP Fatal error: Call to undefined function mailparse_msg_create() in ... mailparse_msg_create() is a part of the Mailparse extension. I tried by relogging with the user after making the change and even restarting the system. What needs to be done so that the change takes effect. Update I checked that php -i | grep 'Configuration File' gives PHP Warning: PHP Startup: Unable to load dynamic library '/usr/lib/php/modules/mailparse.so' - /usr/lib/php/modules/mailparse.so: cannot open shared object file: No such file or directory in Unknown on line 0 Configuration File (php.ini) Path => /etc Loaded Configuration File => /etc/php.ini Update 2 I copied the mailparse.so from /opt/lampp/lib/php/extensions/no-debug-non-zts-20090626 and put it in /usr/lib/php/modules. I added extension=mailparse.so to /etc/php.ini as well. But it still showed this warning PHP Warning: PHP Startup: Unable to load dynamic library ... As told by Lekensteyn, I did ldd /usr/lib/php/modules/mailparse.so and got ldd: warning: you do not have execution permission for /usr/lib/php/modules/mailparse.so' So I gave execute permission. Then ldd /usr/lib/php/modules/mailparse.so showed linux-gate.so.1 => (0x00110000) libc.so.6 => /lib/libc.so.6 (0x0011d000) /lib/ld-linux.so.2 (0x003aa000) which looks normal. BUt now, running php command says PHP Warning: PHP Startup: Unable to load dynamic library '/usr/lib/php/modules/mailparse.so' - /usr/lib/php/modules/mailparse.so: undefined symbol: mbfl_name2no_encoding in Unknown on line 0

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  • Make dhcp assign same IP and hostname for different interfaces at one machine

    - by Egeshi
    I have a feeling that question itself looks stupid but it is not. Please let me clarify. I have dynamic DNS with BIND and NIS configured at my LAN and have laptop which I am using in both wireless and wired mode. I mean that sometimes I have to use wired interface to achieve higher throughput but most of time I don't need it and using wireless mode. Everything works great. Issue is that I want both interfaces get same IP from DHCP. Just for convenient firewall setup. If I add both hosts to dhcp in this manner # bt wireless host bt { hardware ethernet 00:1f:1f:62:60:28; fixed-address 172.16.77.110; } # bt wired host bt { hardware ethernet 00:14:22:b7:5a:de; fixed-address 172.16.77.110; } DHCP says logs following message dhcpd: Dynamic and static leases present for 172.16.77.110 dhcpd: Remove host declaration bt-wired or remove 172.16.77.110 dhcpd: from the dynamic address pool for 172.16/16 Host records are added outside of any subnet, but it makes no difference if I put them there, effect is still the same. This is not critical but either is not my whim because even if DHCP seems to work fine for that "bt" host, I cannot make connection TO it from remote machine anymore with this definitely incorrect DHCP config. I'd be thankful if one spares a minute for advice about how to configure DHCPD correctly. UPDATE. I realize that there's a soulution to assign different hostname in DHCP config but would like to use benefits of short host names.

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  • Apache MaxClients doubt

    - by Milan Babuškov
    I have a busy Apache server serving only dynamic PHP+MySQL pages. It is a prefork Apache, version 2.2.4 with following config: KeepAlive off StartServers 8 MinSpareServers 32 MaxSpareServers 64 ServerLimit 512 MaxClients 512 MaxRequestsPerChild 4000 MaxClients/ServerLimit used to be set to 256, but I got the following error in error_log so I increased it: [error] server reached MaxClients setting, consider raising the MaxClients setting It seems to work now, but I have a doubt. Looking at MySQL log of queries, I have a couple hundred clients per seconds, but "ps ax" only shows 8, 9 or 10 processes running: [root@engine ~]# ps ax | grep http | wc -l 10 I even got this many processes when the above error message was shown in error_log. This made me investigate further. When I run netstat -a, I get something like this: tcp 0 0 engine:http adsl-105-143.teol.net:21453 TIME_WAIT tcp 0 0 engine:http 118-36.static.kds:mck-ivpip TIME_WAIT tcp 0 0 engine:http 118-36.static:oce-snmp-trap TIME_WAIT tcp 0 0 engine:http 118-36.static.kd:unifyadmin TIME_WAIT tcp 0 0 engine:http cable-188-2-25-29.dyna:4906 TIME_WAIT tcp 0 0 engine:http adsl-105-143.teol.net:21458 TIME_WAIT tcp 0 0 engine:http 109-92-83-91.dynamic.:62821 TIME_WAIT tcp 0 0 engine:http cable-89-216-142-192.:63576 TIME_WAIT tcp 0 0 engine:http 109-92-83-91.dynamic.:62819 TIME_WAIT tcp 1081 0 engine:http pttnetadsl38-36.ptt.r:50496 ESTABLISHED tcp 0 0 engine:http cable-188-2-36-196.dyn:4136 TIME_WAIT tcp 0 0 engine:http cable-89-216-142-192.:63580 TIME_WAIT tcp 0 0 engine:http cable-89-216-142-192.:63581 TIME_WAIT etc. When counting those, I get: [root@engine ~]# netstat -a | grep http | wc -l 431 Can anyone tell me what is really going on here and how to make sure my server keeps working, because I only use 50% of available RAM in machine?

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  • Scaling a node.js application, nginx as a base server, but varnish or redis for caching?

    - by AntelopeSalad
    I'm not close to being well versed in using nginx or varnish but this is my setup at the moment. I have a node.js server running which is serving either json, html templates, or socket.io events. Then I have nginx running in front of node which is serving all static content (css, js, etc.). At this point I would like to cache both static content and dynamic content to memory. It's to my understanding that varnish can cache static content quite well and it wouldn't require touching my application code. I also think it's capable of caching dynamic content too but there cannot be any cookie headers? I do use redis at the moment for holding session data and planned to use it for other things in the future like keeping track of non-crucial but fun stats. I just have no idea how I should handle caching everything on the site. I think it comes down to these options but there might be more: Throw varnish in front of nginx and let varnish cache static pages, no app code changes. Redis would cache dynamic db calls which would require modifying my app code. Ignore using varnish completely and let redis handle caching everything, then use one of the nginx-redis modules. I'm not sure if this would require a lot of app code changes (for the static files). I'm not having any luck finding benchmarks that compare nginx+varnish vs nginx+redis and I'm too inexperienced to bench it myself (high chances of my configs being awful). I'm basically looking for the solution that would be the most efficient in terms of req/sec and scalable in the future (throw new hardware at the problem + maybe adjust some values in a config = new servers up and running semi-painlessly).

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  • Designing a persistent asynchronous TCP protocol

    - by dogglebones
    I have got a collection of web sites that need to send time-sensitive messages to host machines all over my metro area, each on its own generally dynamic IP. Until now, I have been doing this the way of the script kiddie: Each host machine runs an (s)FTP server, or an HTTP(s) server, and correspondingly has a certain port opened up by its gateway. Each host machine runs a program that watches a certain folder and automatically opens or prints or exec()s when a new file of a given extension shows up. Dynamic IP addresses are accommodated using a dynamic DNS service. Each web site does cURL or fsockopen or whatever and communicates directly with its recipient as-needed. This approach has been suprisingly reliable, however obvious issues have come up and the situation needs to be addressed. As stated, these messages are time-sensitive and failures need to be detected within minutes of submission by end-users. What I'm doing is building a messaging protocol. It will run on a machine and connection in my control. As far as the service is concerned, there is no distinction between web site and host machine -- there is only one device sending a message to another device. So that's where I'm at right now. I've got a skeleton server and a skeleton client. They can negotiate high-quality authentication and encryption. The (TCP) connection is persistent and asynchronous, and can handle delimited (i.e., read until \r\n or whatever) as well as length-prefixed (i.e., read exactly n bytes) messages. Unless somebody gives me a better idea, I think I'll handle messages as byte arrays. So I'm looking for suggestions on how to model the protocol itself -- at the application level. I'll mostly be transferring XML and DLM type files, as well as control messages for things like "handshake" and "is so-and-so online?" and so forth. Is there anything really stupid in my train of thought? Or anything I should read about before I get started? Stuff like that -- please and thanks.

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  • Can't start my phpMyAdmin

    - by vrynxzent
    i am creating my own portable server but i can't make it to run the phpMyAdmin, the mysql, php and apache is running except for phpMyAdmin. When i check Apache's error log, it states [Fri Nov 09 08:54:37 2012] [warn] pid file F:/Drive WebServer/Drive WebServer/bin/Debug/Apache2bak/logs/httpd.pid overwritten -- Unclean shutdown of previous Apache run? PHP Warning: PHP Startup: Unable to load dynamic library './php_mysql.dll' - The specified module could not be found.\r\n in Unknown on line 0 PHP Warning: PHP Startup: Unable to load dynamic library './php_mysqli.dll' - The specified module could not be found.\r\n in Unknown on line 0 [Fri Nov 09 08:54:37 2012] [notice] Apache/2.0.64 (Win32) PHP/5.2.17 configured -- resuming normal operations [Fri Nov 09 08:54:37 2012] [notice] Server built: Oct 18 2010 01:36:23 [Fri Nov 09 08:54:37 2012] [notice] Parent: Created child process 6784 i manually assign the exact path for this F:/php/ext/php_mysql.dll PHP Warning: PHP Startup: Unable to load dynamic library 'F:/php/ext/php_mysql.dll' - The specified module could not be found.\r\n in Unknown on line 0 but still the same error. i set this option in php.ini extension_dir = "./" another error goes pops out It says libmysql.dll is missing. PHP Version : 5.2.17 Any help would be appreciated. ;)

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  • Hidden Features of C#?

    - by Serhat Özgel
    This came to my mind after I learned the following from this question: where T : struct We, C# developers, all know the basics of C#. I mean declarations, conditionals, loops, operators, etc. Some of us even mastered the stuff like Generics, anonymous types, lambdas, linq, ... But what are the most hidden features or tricks of C# that even C# fans, addicts, experts barely know? Here are the revealed features so far: Keywords yield by Michael Stum var by Michael Stum using() statement by kokos readonly by kokos as by Mike Stone as / is by Ed Swangren as / is (improved) by Rocketpants default by deathofrats global:: by pzycoman using() blocks by AlexCuse volatile by Jakub Šturc extern alias by Jakub Šturc Attributes DefaultValueAttribute by Michael Stum ObsoleteAttribute by DannySmurf DebuggerDisplayAttribute by Stu DebuggerBrowsable and DebuggerStepThrough by bdukes ThreadStaticAttribute by marxidad FlagsAttribute by Martin Clarke ConditionalAttribute by AndrewBurns Syntax ?? operator by kokos number flaggings by Nick Berardi where T:new by Lars Mæhlum implicit generics by Keith one-parameter lambdas by Keith auto properties by Keith namespace aliases by Keith verbatim string literals with @ by Patrick enum values by lfoust @variablenames by marxidad event operators by marxidad format string brackets by Portman property accessor accessibility modifiers by xanadont ternary operator (?:) by JasonS checked and unchecked operators by Binoj Antony implicit and explicit operators by Flory Language Features Nullable types by Brad Barker Currying by Brian Leahy anonymous types by Keith __makeref __reftype __refvalue by Judah Himango object initializers by lomaxx format strings by David in Dakota Extension Methods by marxidad partial methods by Jon Erickson preprocessor directives by John Asbeck DEBUG pre-processor directive by Robert Durgin operator overloading by SefBkn type inferrence by chakrit boolean operators taken to next level by Rob Gough pass value-type variable as interface without boxing by Roman Boiko programmatically determine declared variable type by Roman Boiko Static Constructors by Chris Easier-on-the-eyes / condensed ORM-mapping using LINQ by roosteronacid Visual Studio Features select block of text in editor by Himadri snippets by DannySmurf Framework TransactionScope by KiwiBastard DependantTransaction by KiwiBastard Nullable<T> by IainMH Mutex by Diago System.IO.Path by ageektrapped WeakReference by Juan Manuel Methods and Properties String.IsNullOrEmpty() method by KiwiBastard List.ForEach() method by KiwiBastard BeginInvoke(), EndInvoke() methods by Will Dean Nullable<T>.HasValue and Nullable<T>.Value properties by Rismo GetValueOrDefault method by John Sheehan Tips & Tricks nice method for event handlers by Andreas H.R. Nilsson uppercase comparisons by John access anonymous types without reflection by dp a quick way to lazily instantiate collection properties by Will JavaScript-like anonymous inline-functions by roosteronacid Other netmodules by kokos LINQBridge by Duncan Smart Parallel Extensions by Joel Coehoorn

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