Search Results

Search found 5101 results on 205 pages for 'expression trees'.

Page 81/205 | < Previous Page | 77 78 79 80 81 82 83 84 85 86 87 88  | Next Page >

  • How to add new filters to CAML queries in SharePoint 2007

    - by uruit
    Normal 0 21 false false false ES-UY X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin-top:0cm; mso-para-margin-right:0cm; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0cm; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} One flexibility SharePoint has is CAML (Collaborative Application Markup Language). CAML it’s a markup language like html that allows developers to do queries against SharePoint lists, it’s syntax is very easy to understand and it allows to add logical conditions like Where, Contains, And, Or, etc, just like a SQL Query. For one of our projects we have the need to do a filter on SharePoint views, the problem here is that the view it’s a list containing a CAML Query with the filters the view may have, so in order to filter the view that’s already been filtered before, we need to append our filters to the existing CAML Query. That’s not a trivial task because the where statement in a CAML Query it’s like this: <Where>   <And>     <Filter1 />     <Filter2 />   </And> </Where> If we want to add a new logical operator, like an OR it’s not just as simple as to append the OR expression like the following example: <Where>   <And>     <Filter1 />     <Filter2 />   </And>   <Or>     <Filter3 />   </Or> </Where> But instead the correct query would be: <Where>   <Or>     <And>       <Filter1 />       <Filter2 />     </And>     <Filter3 />   </Or> </Where> Notice that the <Filter# /> tags are for explanation purpose only. In order to solve this problem we created a simple component, it has a method that receives the current query (could be an empty query also) and appends the expression you want to that query. Example: string currentQuery = @“ <Where>    <And>     <Contains><FieldRef Name='Title' /><Value Type='Text'>A</Value></Contains>     <Contains><FieldRef Name='Title' /><Value Type='Text'>B</Value></Contains>   </And> </Where>”; currentQuery = CAMLQueryBuilder.AppendQuery(     currentQuery,     “<Contains><FieldRef Name='Title' /><Value Type='Text'>C</Value></Contains>”,     CAMLQueryBuilder.Operators.Or); The fist parameter this function receives it’s the actual query, the second it’s the filter you want to add, and the third it’s the logical operator, so basically in this query we want all the items that the title contains: the character A and B or the ones that contains the character C. The result query is: <Where>   <Or>      <And>       <Contains><FieldRef Name='Title' /><Value Type='Text'>A</Value></Contains>       <Contains><FieldRef Name='Title' /><Value Type='Text'>B</Value></Contains>     </And>     <Contains><FieldRef Name='Title' /><Value Type='Text'>C</Value></Contains>   </Or> </Where>     The code:   First of all we have an enumerator inside the CAMLQueryBuilder class that has the two possible Options And, Or. public enum Operators { And, Or }   Then we have the main method that’s the one that performs the append of the filters. public static string AppendQuery(string containerQuery, string logicalExpression, Operators logicalOperator){   In this method the first we do is create a new XmlDocument and wrap the current query (that may be empty) with a “<Query></Query>” tag, because the query that comes with the view doesn’t have a root element and the XmlDocument must be a well formatted xml.   XmlDocument queryDoc = new XmlDocument(); queryDoc.LoadXml("<Query>" + containerQuery + "</Query>");   The next step is to create a new XmlDocument containing the logical expression that has the filter needed.   XmlDocument logicalExpressionDoc = new XmlDocument(); logicalExpressionDoc.LoadXml("<root>" + logicalExpression + "</root>"); In these next four lines we extract the expression from the recently created XmlDocument and create an XmlElement.                  XmlElement expressionElTemp = (XmlElement)logicalExpressionDoc.SelectSingleNode("/root/*"); XmlElement expressionEl = queryDoc.CreateElement(expressionElTemp.Name); expressionEl.InnerXml = expressionElTemp.InnerXml;   Below are the main steps in the component logic. The first “if” checks if the actual query doesn’t contains a “Where” clause. In case there’s no “Where” we add it and append the expression.   In case that there’s already a “Where” clause, we get the entire statement that’s inside the “Where” and reorder the query removing and appending elements to form the correct query, that will finally filter the list.   XmlElement whereEl; if (!containerQuery.Contains("Where")) { queryDoc.FirstChild.AppendChild(queryDoc.CreateElement("Where")); queryDoc.SelectSingleNode("/Query/Where").AppendChild(expressionEl); } else { whereEl = (XmlElement)queryDoc.SelectSingleNode("/Query/Where"); if (!containerQuery.Contains("<And>") &&                 !containerQuery.Contains("<Or>"))        {              XmlElement operatorEl = queryDoc.CreateElement(GetName(logicalOperator)); XmlElement existingExpression = (XmlElement)whereEl.SelectSingleNode("/Query/Where/*"); whereEl.RemoveChild(existingExpression);                 operatorEl.AppendChild(existingExpression);               operatorEl.AppendChild(expressionEl);                 whereEl.AppendChild(operatorEl);        }        else        {              XmlElement operatorEl = queryDoc.CreateElement(GetName(logicalOperator)); XmlElement existingOperator = (XmlElement)whereEl.SelectSingleNode("/Query/Where/*");                 whereEl.RemoveChild(existingOperator);               operatorEl.AppendChild(existingOperator);               operatorEl.AppendChild(expressionEl);                 whereEl.AppendChild(operatorEl);         }  }  return queryDoc.FirstChild.InnerXml }     Finally the GetName method converts the Enum option to his string equivalent.   private static string GetName(Operators logicalOperator) {       return Enum.GetName(typeof(Operators), logicalOperator); }        Normal 0 21 false false false ES-UY X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin-top:0cm; mso-para-margin-right:0cm; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0cm; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Normal 0 21 false false false ES-UY X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin-top:0cm; mso-para-margin-right:0cm; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0cm; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} This component helped our team a lot using SharePoint 2007 and modifying the queries, but now in SharePoint 2010; that wouldn’t be needed because of the incorporation of LINQ to SharePoint. This new feature enables the developers to do typed queries against SharePoint lists without the need of writing any CAML code.  But there is still much development to the 2007 version, so I hope this information is useful for other members.  Post Normal 0 21 false false false ES-UY X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi; mso-fareast-language:EN-US;} written by Sebastian Rodriguez - Portals and Collaboration Solutions @ UruIT

    Read the article

  • CodePlex Daily Summary for Monday, June 06, 2011

    CodePlex Daily Summary for Monday, June 06, 2011Popular ReleasesSharepoint 2010 Diagnostic Log Compression: Sharepoint 2010 Diagnostic Log Compression v1.0: ====================== Requirements: Microsoft Sharepoint 2010 Foundation or Microsoft Sharepoint 2010 Server Release Version : 1.0PowerShell SQL Developer Tools: SQLDevTools_Module (folder) Version 0.1.0: SQLDevTools Module version 0.1.0(alpha release) Just unzip the file and move the folder "SQLDevTools" into your User "WindowsPowerShell\Modules" folder. "C:\Users\UserName...\Documents\WindowsPowerShell\Modules\SQLDevTools" Then, to load *module at either the PowerShell Console or ISE, use: Import-Module SQLDevTools To remove module use: Remove-Module SQLDevTools Again, you need have SQL Server 2008 (or above). or the standalone version of "SQL Server Management Studio 2008 R2 " installed ...ShowUI: Write-UI -in PowerShell: ShowUI: ShowUI is a PowerShell module to help you write rich user interfaces in script.SQL Compact Query Analyzer: Build 0.2.0.0: Beta build of SQL Compact Query Analyzer Features: - Execute SQL Queries against a SQL Server Compact Edition database - Easily edit the contents of the database - Supports SQLCE 3.5 and 4.0 Prerequisites: - .NET Framework 4.0Media Companion: MC 3.405b weekly: Extract the entire archive to a folder which has user access rights, eg desktop, documents etc. Refer to the documentation on this site for the Installation & Setup Guide Important! If you are upgrading from a version of MC before 3.404 then..... Due to an issue where the date added & the full genre information was not being read into the Movie cache, it is highly recommended that you perform a Rebuild Movies when first running this latest version. This will read in the information from the ...Babylon Toolkit: Babylon.Toolkit v1.0.4: Note about samples: In order to run samples, you need to configure visual studio to run them as an "Out-of-browser application". in order to do that, go to the property page of a sample project, go to the Debug tab, and check the "Out-of-browser application" radio. New features : New Effects BasicEffect3Lights (3 dir lights instead of 1 position light) CartoonEffect (work in progress) SkinnedEffect (with normal and specular map support) SplattingEffect (for multi-texturing with smooth ...SizeOnDisk: 1.0.8.2: With installerTerrariViewer: TerrariViewer v2.5: Added new items associated with Terraria v1.0.3 to the character editor. Fixed multiple bugs with Piggy Bank EditorySterling NoSQL OODB for .NET 4.0, Silverlight 4 and 5, and Windows Phone 7: Sterling OODB v1.5: Welcome to the Sterling 1.5 RTM. This version is backwards compatible without modification to the 1.4 beta. For the 1.0, you will need to upgrade your database. Please see this discussion for details. You must modify your 1.0 code for persistence. The 1.5 version defaults to an in-memory driver. To save to isolated storage or use one of the new mechanisms, see the available drivers and pass an instance of the appropriate one to your database (different databases may use different drivers). ...patterns & practices: Project Silk: Project Silk Community Drop 10 - June 3, 2011: Changes from previous drop: Many code changes: please see the readme.mht for details. New "Application Notifications" chapter. Updated "Server-Side Implementation" chapter. Guidance Chapters Ready for Review The Word documents for the chapters are included with the source code in addition to the CHM to help you provide feedback. The PDF is provided as a separate download for your convenience. Installation Overview To install and run the reference implementation, you must perform the fol...Claims Based Identity & Access Control Guide: Release Candidate: Highlights of this release This is the release candidate drop of the new "Claims Identity Guide" edition. In this release you will find: All code samples, including all ACS v2: ACS as a Federation Provider - Showing authentication with LiveID, Google, etc. ACS as a FP with Multiple Business Partners. ACS and REST endpoints. Using a WP7 client with REST endpoints. All ACS specific chapters. Two new chapters on SharePoint (SSO and Federation) All revised v1 chapters We are now ...Terraria Map Generator: TerrariaMapTool 1.0.0.4 Beta: 1) Fixed the generated map.html file so that the file:/// is included in the base path. 2) Added the ability to use parallelization during generation. This will cause the program to use as many threads as there are physical cores. 3) Fixed some background overdraw.Caliburn Micro: WPF, Silverlight and WP7 made easy.: Caliburn.Micro v1.1 RTW: Download ContentsDebug and Release Assemblies Samples Changes.txt License.txt Release Highlights For WP7A new Tombstoning API based on ideas from Fluent NHibernate A new Launcher/Chooser API Strongly typed Navigation SimpleContainer included The full phone lifecycle is made easy to work with ie. we figure out whether your app is actually Resurrecting or just Continuing for you For WPFSupport for the Client Profile Better support for WinForms integration All PlatformsA power...VidCoder: 0.9.1: Added color coding to the Log window. Errors are highlighted in red, HandBrake logs are in black and VidCoder logs are in dark blue. Moved enqueue button to the right with the other control buttons. Added logic to report failures when errors are logged during the encode or when the encode finishes prematurely. Added Copy button to Log window. Adjusted audio track selection box to always show the full track name. Changed encode job progress bar to also be colored yellow when the enco...AutoLoL: AutoLoL v2.0.1: - Fixed a small bug in Auto Login - Fixed the updaterEPPlus-Create advanced Excel 2007 spreadsheets on the server: EPPlus 2.9.0.1: EPPlus-Create advanced Excel 2007 spreadsheets on the server This version has been updated to .Net Framework 3.5 New Features Data Validation. PivotTables (Basic functionalliy...) Support for worksheet data sources. Column, Row, Page and Data fields. Date and Numeric grouping Build in styles. ...and more And some minor new features... Ranges Text-Property|Get the formated value AutofitColumns-method to set the column width from the content of the range LoadFromCollection-metho...jQuery ASP.Net MVC Controls: Version 1.4.0.0: Version 1.4.0.0 contains the following additions: Upgraded to MVC 3.0 Upgraded to jQuery 1.6.1 (Though the project supports all jQuery version from 1.4.x onwards) Upgraded to jqGrid 3.8 Better Razor View-Engine support Better Pager support, includes support for custom pagers Added jqGrid toolbar buttons support Search module refactored, with full suport for multiple filters and ordering And Code cleanup, bug-fixes and better controller configuration support.NetOffice - The easiest way to use Office in .NET: NetOffice Release 0.8b: Changes: - fix critical issue 15922(AccessViolationException) once and for all ...update is strongly recommended Known Issues: - some addin ribbon examples has a COM Register function with missing codebase entry(win32 registry) ...the problem is only affected to c# examples. fixed in latest source code. NetOffice\ReleaseTags\NetOffice Release 0.8.rar Includes: - Runtime Binaries and Source Code for .NET Framework:......v2.0, v3.0, v3.5, v4.0 - Tutorials in C# and VB.Net:...................Serviio for Windows Home Server: Beta Release 0.5.2.0: Ready for widespread beta. Synchronized build number to Serviio version to avoid confusion.AcDown????? - Anime&Comic Downloader: AcDown????? v3.0 Beta4: ??AcDown?????????????,??????????????,????、????。?????Acfun????? ????32??64? Windows XP/Vista/7 ????????????? ??:????????Windows XP???,?????????.NET Framework 2.0???(x86)?.NET Framework 2.0???(x64),?????"?????????"??? ??v3.0 Beta4 2011-5-31?? ???Bilibili.us????? ???? ?? ???"????" ???Bilibili.us??? ??????? ?? ??????? ?? ???????? ?? ?? ???Bilibili.us?????(??????????????????) ??????(6.cn)?????(????) ?? ?????Acfun?????????? ?????????????? ???QQ???????? ????????????Discussion...New Projects.NET library for Audiogalaxy: AgNet is a .NET Client library for the Audiogalaxy APIAsuro scanner: A asuro programm which can recognize light values and perform predefined actions for them. This was realised for school project.AutoComplete.Net (for Asp.Net and Asp.Net MVC): AutoComplete.Net is a wrapper around the JQuery UI Autocomplete widget. It makes it easier to add autocomplete functionalities without having to bother with tons of javascript. Includes a WebControl for your Asp.Net web applications and a bunch of extension methods for your Asp.Net MVC web applications. Their purpose is to provide developers with an easy interface to the cool JQuery UI autocomplete Widget. It's developed in C#.AveSoft Advance Keylogger: Free and completely open source keystroke logging application, allows you to capture and record all keyboard input to file. Program is extremely small and lightweight, can run in a hidden mode, upload log file to specified web server. Due to open source nature, software is secure and transparent. Main Features Captures all keyboard input Caching and low level hooks uses minimal amount of CPU cycles Highly customizable Hidden mode Windows integration Log file...DDDProjector: DDDPrjector ?、DDD (Domain Driven Design: ????????) ?????????????????????????????????????、C# ???????????????????。 ???????????????????? C# ????????????????、??????????????????????????。 O/R ?????? NHibernate ??????。DogTouch: DogTouchEVMDOCS Reports: This project contain diploma of student VSTU. The project is devoted to automating the learning process at the university. Contains reports in OpenOfficeFidely - Search Query Compilation Framework: Fidely is a framework to implement a search query compiler that parses a search query string and builds up an expression tree (Expression<Func<T, bool>>) to filter a collection object. Fidely allows you to customize processes of parsing a query string and building up an expression tree, so you can create various search query compilers. The goal of this project is to make it easy to implement collection filtering features into your application.Frets: Frets is a library for creating and printing guitar chord diagrams. FuncLib: C# automatic differentiation library, transparent use with operator overloading, unlimited order of differentiation and unlimited number of variables, on-the-fly function compilation to IL code for very fast evaluation.ITAP: a management system for HCM IU's IELTS simulation examjQXB/M Expression Binder: JQ Expression Binder is a lightweigth framework (10 kbytes) for the association between javascript objects and HTML elements. Based on jQuery provides a natural and flexible way to process the data exchanged between client and server in a real WEB 2.0 paradigm. Using a few custom attributes to decorate yout HTML tags now you are enabled to take complete control over the managing of your business data directly inside yours web pages. Easy integration with ASP.NET WEBForm web applications, ...Log Processor: This software helps you to automatically analyze and process data in files (such as plain text logs, binary dumps...) based on : - plugins (for multiple input/output file types support) - plain text rules files (for a complete customization of the analysis needed) You'll then be able to easily produce stats reports from you application logs.MiniIndexer: A web application the demonstrates how to make a simple indexing search engine backed by a relational database. Monads: Monads helpers for .NET, Silverlight and Windows Phone 7.Movie Browser: Movie Browser helps collecting information from imdb and manage personal movie folders.Opc Configurable Xml Server/Service (OCXS): A Microsoft .NET 4.0 C# OPC XML Data Access 1.0 Server/ServiceSQL DAL: Data access layerTankMate: A simple Visual Basic application that lists and manages all your fish tanks. software initially designed to list fish tanks and enter their width/height/depth in inches and it display their volume in litres tank calculator was then expanded to alert if water needs changing after set interval of days number of days between changes is settable for each tank any sound file can be used for alert sounds has online update feature to keep it up to date Twoosh!: Simply, a fully-functional Twitter client for Windows... Twoosh makes it easier for Tweeple to Tweet. You'll no longer have to wait for the Twitter page to load or see the fail whale error page. It's developed in Visual Basic .NET 2008.WCF RIA Services for Azure Tables and SQL/Azure: Th project demos RIA services with POCO objects using two different back end data storage technologies, SQL/Azure and Azure Table Storage. The example shows a simple association between two tables - department and employee for read, insert and update operationsWindows Azure Storage Console Client: Windows Azure Storage Console ClientXNA 4.0 VirtualCompass: VirtualCompass is an incredibly simple and easy to use library for path finding in Microsoft's XNA 4.0 . It implements A* (A-star) path finding techniques to find the shortest path. This is an alpha status project. Limited testing and optimization thus far. Developed in C#.

    Read the article

  • Securing an ASP.NET MVC 2 Application

    - by rajbk
    This post attempts to look at some of the methods that can be used to secure an ASP.NET MVC 2 Application called Northwind Traders Human Resources.  The sample code for the project is attached at the bottom of this post. We are going to use a slightly modified Northwind database. The screen capture from SQL server management studio shows the change. I added a new column called Salary, inserted some random salaries for the employees and then turned off AllowNulls.   The reporting relationship for Northwind Employees is shown below.   The requirements for our application are as follows: Employees can see their LastName, FirstName, Title, Address and Salary Employees are allowed to edit only their Address information Employees can see the LastName, FirstName, Title, Address and Salary of their immediate reports Employees cannot see records of non immediate reports.  Employees are allowed to edit only the Salary and Title information of their immediate reports. Employees are not allowed to edit the Address of an immediate report Employees should be authenticated into the system. Employees by default get the “Employee” role. If a user has direct reports, they will also get assigned a “Manager” role. We use a very basic empId/pwd scheme of EmployeeID (1-9) and password test$1. You should never do this in an actual application. The application should protect from Cross Site Request Forgery (CSRF). For example, Michael could trick Steven, who is already logged on to the HR website, to load a page which contains a malicious request. where without Steven’s knowledge, a form on the site posts information back to the Northwind HR website using Steven’s credentials. Michael could use this technique to give himself a raise :-) UI Notes The layout of our app looks like so: When Nancy (EmpID 1) signs on, she sees the default page with her details and is allowed to edit her address. If Nancy attempts to view the record of employee Andrew who has an employeeID of 2 (Employees/Edit/2), she will get a “Not Authorized” error page. When Andrew (EmpID 2) signs on, he can edit the address field of his record and change the title and salary of employees that directly report to him. Implementation Notes All controllers inherit from a BaseController. The BaseController currently only has error handling code. When a user signs on, we check to see if they are in a Manager role. We then create a FormsAuthenticationTicket, encrypt it (including the roles that the employee belongs to) and add it to a cookie. private void SetAuthenticationCookie(int employeeID, List<string> roles) { HttpCookiesSection cookieSection = (HttpCookiesSection) ConfigurationManager.GetSection("system.web/httpCookies"); AuthenticationSection authenticationSection = (AuthenticationSection) ConfigurationManager.GetSection("system.web/authentication"); FormsAuthenticationTicket authTicket = new FormsAuthenticationTicket( 1, employeeID.ToString(), DateTime.Now, DateTime.Now.AddMinutes(authenticationSection.Forms.Timeout.TotalMinutes), false, string.Join("|", roles.ToArray())); String encryptedTicket = FormsAuthentication.Encrypt(authTicket); HttpCookie authCookie = new HttpCookie(FormsAuthentication.FormsCookieName, encryptedTicket); if (cookieSection.RequireSSL || authenticationSection.Forms.RequireSSL) { authCookie.Secure = true; } HttpContext.Current.Response.Cookies.Add(authCookie); } We read this cookie back in Global.asax and set the Context.User to be a new GenericPrincipal with the roles we assigned earlier. protected void Application_AuthenticateRequest(Object sender, EventArgs e){ if (Context.User != null) { string cookieName = FormsAuthentication.FormsCookieName; HttpCookie authCookie = Context.Request.Cookies[cookieName]; if (authCookie == null) return; FormsAuthenticationTicket authTicket = FormsAuthentication.Decrypt(authCookie.Value); string[] roles = authTicket.UserData.Split(new char[] { '|' }); FormsIdentity fi = (FormsIdentity)(Context.User.Identity); Context.User = new System.Security.Principal.GenericPrincipal(fi, roles); }} We ensure that a user has permissions to view a record by creating a custom attribute AuthorizeToViewID that inherits from ActionFilterAttribute. public class AuthorizeToViewIDAttribute : ActionFilterAttribute{ IEmployeeRepository employeeRepository = new EmployeeRepository(); public override void OnActionExecuting(ActionExecutingContext filterContext) { if (filterContext.ActionParameters.ContainsKey("id") && filterContext.ActionParameters["id"] != null) { if (employeeRepository.IsAuthorizedToView((int)filterContext.ActionParameters["id"])) { return; } } throw new UnauthorizedAccessException("The record does not exist or you do not have permission to access it"); }} We add the AuthorizeToView attribute to any Action method that requires authorization. [HttpPost][Authorize(Order = 1)]//To prevent CSRF[ValidateAntiForgeryToken(Salt = Globals.EditSalt, Order = 2)]//See AuthorizeToViewIDAttribute class[AuthorizeToViewID(Order = 3)] [ActionName("Edit")]public ActionResult Update(int id){ var employeeToEdit = employeeRepository.GetEmployee(id); if (employeeToEdit != null) { //Employees can edit only their address //A manager can edit the title and salary of their subordinate string[] whiteList = (employeeToEdit.IsSubordinate) ? new string[] { "Title", "Salary" } : new string[] { "Address" }; if (TryUpdateModel(employeeToEdit, whiteList)) { employeeRepository.Save(employeeToEdit); return RedirectToAction("Details", new { id = id }); } else { ModelState.AddModelError("", "Please correct the following errors."); } } return View(employeeToEdit);} The Authorize attribute is added to ensure that only authorized users can execute that Action. We use the TryUpdateModel with a white list to ensure that (a) an employee is able to edit only their Address and (b) that a manager is able to edit only the Title and Salary of a subordinate. This works in conjunction with the AuthorizeToViewIDAttribute. The ValidateAntiForgeryToken attribute is added (with a salt) to avoid CSRF. The Order on the attributes specify the order in which the attributes are executed. The Edit View uses the AntiForgeryToken helper to render the hidden token: ......<% using (Html.BeginForm()) {%><%=Html.AntiForgeryToken(NorthwindHR.Models.Globals.EditSalt)%><%= Html.ValidationSummary(true, "Please correct the errors and try again.") %><div class="editor-label"> <%= Html.LabelFor(model => model.LastName) %></div><div class="editor-field">...... The application uses View specific models for ease of model binding. public class EmployeeViewModel{ public int EmployeeID; [Required] [DisplayName("Last Name")] public string LastName { get; set; } [Required] [DisplayName("First Name")] public string FirstName { get; set; } [Required] [DisplayName("Title")] public string Title { get; set; } [Required] [DisplayName("Address")] public string Address { get; set; } [Required] [DisplayName("Salary")] [Range(500, double.MaxValue)] public decimal Salary { get; set; } public bool IsSubordinate { get; set; }} To help with displaying readonly/editable fields, we use a helper method. //Simple extension method to display a TextboxFor or DisplayFor based on the isEditable variablepublic static MvcHtmlString TextBoxOrLabelFor<TModel, TProperty>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TProperty>> expression, bool isEditable){ if (isEditable) { return htmlHelper.TextBoxFor(expression); } else { return htmlHelper.DisplayFor(expression); }} The helper method is used in the view like so: <%=Html.TextBoxOrLabelFor(model => model.Title, Model.IsSubordinate)%> As mentioned in this post, there is a much easier way to update properties on an object. Download Demo Project VS 2008, ASP.NET MVC 2 RTM Remember to change the connectionString to point to your Northwind DB NorthwindHR.zip Feedback and bugs are always welcome :-)

    Read the article

  • Using delegates in C# (Part 2)

    - by rajbk
    Part 1 of this post can be read here. We are now about to see the different syntaxes for invoking a delegate and some c# syntactic sugar which allows you to code faster. We have the following console application. 1: public delegate double Operation(double x, double y); 2:  3: public class Program 4: { 5: [STAThread] 6: static void Main(string[] args) 7: { 8: Operation op1 = new Operation(Division); 9: double result = op1.Invoke(10, 5); 10: 11: Console.WriteLine(result); 12: Console.ReadLine(); 13: } 14: 15: static double Division(double x, double y) { 16: return x / y; 17: } 18: } Line 1 defines a delegate type called Operation with input parameters (double x, double y) and a return type of double. On Line 8, we create an instance of this delegate and set the target to be a static method called Division (Line 15) On Line 9, we invoke the delegate (one entry in the invocation list). The program outputs 5 when run. The language provides shortcuts for creating a delegate and invoking it (see line 9 and 11). Line 9 is a syntactical shortcut for creating an instance of the Delegate. The C# compiler will infer on its own what the delegate type is and produces intermediate language that creates a new instance of that delegate. Line 11 uses a a syntactical shortcut for invoking the delegate by removing the Invoke method. The compiler sees the line and generates intermediate language which invokes the delegate. When this code is compiled, the generated IL will look exactly like the IL of the compiled code above. 1: public delegate double Operation(double x, double y); 2:  3: public class Program 4: { 5: [STAThread] 6: static void Main(string[] args) 7: { 8: //shortcut constructor syntax 9: Operation op1 = Division; 10: //shortcut invoke syntax 11: double result = op1(10, 2); 12: 13: Console.WriteLine(result); 14: Console.ReadLine(); 15: } 16: 17: static double Division(double x, double y) { 18: return x / y; 19: } 20: } C# 2.0 introduced Anonymous Methods. Anonymous methods avoid the need to create a separate method that contains the same signature as the delegate type. Instead you write the method body in-line. There is an interesting fact about Anonymous methods and closures which won’t be covered here. Use your favorite search engine ;-)We rewrite our code to use anonymous methods (see line 9): 1: public delegate double Operation(double x, double y); 2:  3: public class Program 4: { 5: [STAThread] 6: static void Main(string[] args) 7: { 8: //Anonymous method 9: Operation op1 = delegate(double x, double y) { 10: return x / y; 11: }; 12: double result = op1(10, 2); 13: 14: Console.WriteLine(result); 15: Console.ReadLine(); 16: } 17: 18: static double Division(double x, double y) { 19: return x / y; 20: } 21: } We could rewrite our delegate to be of a generic type like so (see line 2 and line 9). You will see why soon. 1: //Generic delegate 2: public delegate T Operation<T>(T x, T y); 3:  4: public class Program 5: { 6: [STAThread] 7: static void Main(string[] args) 8: { 9: Operation<double> op1 = delegate(double x, double y) { 10: return x / y; 11: }; 12: double result = op1(10, 2); 13: 14: Console.WriteLine(result); 15: Console.ReadLine(); 16: } 17: 18: static double Division(double x, double y) { 19: return x / y; 20: } 21: } The .NET 3.5 framework introduced a whole set of predefined delegates for us including public delegate TResult Func<T1, T2, TResult>(T1 arg1, T2 arg2); Our code can be modified to use this delegate instead of the one we declared. Our delegate declaration has been removed and line 7 has been changed to use the Func delegate type. 1: public class Program 2: { 3: [STAThread] 4: static void Main(string[] args) 5: { 6: //Func is a delegate defined in the .NET 3.5 framework 7: Func<double, double, double> op1 = delegate (double x, double y) { 8: return x / y; 9: }; 10: double result = op1(10, 2); 11: 12: Console.WriteLine(result); 13: Console.ReadLine(); 14: } 15: 16: static double Division(double x, double y) { 17: return x / y; 18: } 19: } .NET 3.5 also introduced lambda expressions. A lambda expression is an anonymous function that can contain expressions and statements, and can be used to create delegates or expression tree types. We change our code to use lambda expressions. 1: public class Program 2: { 3: [STAThread] 4: static void Main(string[] args) 5: { 6: //lambda expression 7: Func<double, double, double> op1 = (x, y) => x / y; 8: double result = op1(10, 2); 9: 10: Console.WriteLine(result); 11: Console.ReadLine(); 12: } 13: 14: static double Division(double x, double y) { 15: return x / y; 16: } 17: } C# 3.0 introduced the keyword var (implicitly typed local variable) where the type of the variable is inferred based on the type of the associated initializer expression. We can rewrite our code to use var as shown below (line 7).  The implicitly typed local variable op1 is inferred to be a delegate of type Func<double, double, double> at compile time. 1: public class Program 2: { 3: [STAThread] 4: static void Main(string[] args) 5: { 6: //implicitly typed local variable 7: var op1 = (x, y) => x / y; 8: double result = op1(10, 2); 9: 10: Console.WriteLine(result); 11: Console.ReadLine(); 12: } 13: 14: static double Division(double x, double y) { 15: return x / y; 16: } 17: } You have seen how we can write code in fewer lines by using a combination of the Func delegate type, implicitly typed local variables and lambda expressions.

    Read the article

  • ASP.NET MVC–How to show asterisk after required field label

    - by DigiMortal
    Usually we have some required fields on our forms and it would be nice if ASP.NET MVC views can detect those fields automatically and display nice red asterisk after field label. As this functionality is not built in I built my own solution based on data annotations. In this posting I will show you how to show red asterisk after label of required fields. Here are the main information sources I used when working out my own solution: How can I modify LabelFor to display an asterisk on required fields? (stackoverflow) ASP.NET MVC – Display visual hints for the required fields in your model (Radu Enuca) Although my code was first written for completely different situation I needed it later and I modified it to work with models that use data annotations. If data member of model has Required attribute set then asterisk is rendered after field. If Required attribute is missing then there will be no asterisk. Here’s my code. You can take just LabelForRequired() methods and paste them to your own HTML extension class. public static class HtmlExtensions {     [SuppressMessage("Microsoft.Design", "CA1006:DoNotNestGenericTypesInMemberSignatures", Justification = "This is an appropriate nesting of generic types")]     public static MvcHtmlString LabelForRequired<TModel, TValue>(this HtmlHelper<TModel> html, Expression<Func<TModel, TValue>> expression, string labelText = "")     {         return LabelHelper(html,             ModelMetadata.FromLambdaExpression(expression, html.ViewData),             ExpressionHelper.GetExpressionText(expression), labelText);     }       private static MvcHtmlString LabelHelper(HtmlHelper html,         ModelMetadata metadata, string htmlFieldName, string labelText)     {         if (string.IsNullOrEmpty(labelText))         {             labelText = metadata.DisplayName ?? metadata.PropertyName ?? htmlFieldName.Split('.').Last();         }           if (string.IsNullOrEmpty(labelText))         {             return MvcHtmlString.Empty;         }           bool isRequired = false;           if (metadata.ContainerType != null)         {             isRequired = metadata.ContainerType.GetProperty(metadata.PropertyName)                             .GetCustomAttributes(typeof(RequiredAttribute), false)                             .Length == 1;         }           TagBuilder tag = new TagBuilder("label");         tag.Attributes.Add(             "for",             TagBuilder.CreateSanitizedId(                 html.ViewContext.ViewData.TemplateInfo.GetFullHtmlFieldName(htmlFieldName)             )         );           if (isRequired)             tag.Attributes.Add("class", "label-required");           tag.SetInnerText(labelText);           var output = tag.ToString(TagRenderMode.Normal);             if (isRequired)         {             var asteriskTag = new TagBuilder("span");             asteriskTag.Attributes.Add("class", "required");             asteriskTag.SetInnerText("*");             output += asteriskTag.ToString(TagRenderMode.Normal);         }         return MvcHtmlString.Create(output);     } } And here’s how to use LabelForRequired extension method in your view: <div class="field">     @Html.LabelForRequired(m => m.Name)     @Html.TextBoxFor(m => m.Name)     @Html.ValidationMessageFor(m => m.Name) </div> After playing with CSS style called .required my example form looks like this: These red asterisks are not part of original view mark-up. LabelForRequired method detected that these properties have Required attribute set and rendered out asterisks after field names. NB! By default asterisks are not red. You have to define CSS class called “required” to modify how asterisk looks like and how it is positioned.

    Read the article

  • We've completed the first iteration

    - by CliveT
    There are a lot of features in C# that are implemented by the compiler and not by the underlying platform. One such feature is a lambda expression. Since local variables cannot be accessed once the current method activation finishes, the compiler has to go out of its way to generate a new class which acts as a home for any variable whose lifetime needs to be extended past the activation of the procedure. Take the following example:     Random generator = new Random();     Func func = () = generator.Next(10); In this case, the compiler generates a new class called c_DisplayClass1 which is marked with the CompilerGenerated attribute. [CompilerGenerated] private sealed class c__DisplayClass1 {     // Fields     public Random generator;     // Methods     public int b__0()     {         return this.generator.Next(10);     } } Two quick comments on this: (i)    A display was the means that compilers for languages like Algol recorded the various lexical contours of the nested procedure activations on the stack. I imagine that this is what has led to the name. (ii)    It is a shame that the same attribute is used to mark all compiler generated classes as it makes it hard to figure out what they are being used for. Indeed, you could imagine optimisations that the runtime could perform if it knew that classes corresponded to certain high level concepts. We can see that the local variable generator has been turned into a field in the class, and the body of the lambda expression has been turned into a method of the new class. The code that builds the Func object simply constructs an instance of this class and initialises the fields to their initial values.     c__DisplayClass1 class2 = new c__DisplayClass1();     class2.generator = new Random();     Func func = new Func(class2.b__0); Reflector already contains code to spot this pattern of code and reproduce the form containing the lambda expression, so this is example is correctly decompiled. The use of compiler generated code is even more spectacular in the case of iterators. C# introduced the idea of a method that could automatically store its state between calls, so that it can pick up where it left off. The code can express the logical flow with yield return and yield break denoting places where the method should return a particular value and be prepared to resume.         {             yield return 1;             yield return 2;             yield return 3;         } Of course, there was already a .NET pattern for expressing the idea of returning a sequence of values with the computation proceeding lazily (in the sense that the work for the next value is executed on demand). This is expressed by the IEnumerable interface with its Current property for fetching the current value and the MoveNext method for forcing the computation of the next value. The sequence is terminated when this method returns false. The C# compiler links these two ideas together so that an IEnumerator returning method using the yield keyword causes the compiler to produce the implementation of an Iterator. Take the following piece of code.         IEnumerable GetItems()         {             yield return 1;             yield return 2;             yield return 3;         } The compiler implements this by defining a new class that implements a state machine. This has an integer state that records which yield point we should go to if we are resumed. It also has a field that records the Current value of the enumerator and a field for recording the thread. This latter value is used for optimising the creation of iterator instances. [CompilerGenerated] private sealed class d__0 : IEnumerable, IEnumerable, IEnumerator, IEnumerator, IDisposable {     // Fields     private int 1__state;     private int 2__current;     public Program 4__this;     private int l__initialThreadId; The body gets converted into the code to construct and initialize this new class. private IEnumerable GetItems() {     d__0 d__ = new d__0(-2);     d__.4__this = this;     return d__; } When the class is constructed we set the state, which was passed through as -2 and the current thread. public d__0(int 1__state) {     this.1__state = 1__state;     this.l__initialThreadId = Thread.CurrentThread.ManagedThreadId; } The state needs to be set to 0 to represent a valid enumerator and this is done in the GetEnumerator method which optimises for the usual case where the returned enumerator is only used once. IEnumerator IEnumerable.GetEnumerator() {     if ((Thread.CurrentThread.ManagedThreadId == this.l__initialThreadId)               && (this.1__state == -2))     {         this.1__state = 0;         return this;     } The state machine itself is implemented inside the MoveNext method. private bool MoveNext() {     switch (this.1__state)     {         case 0:             this.1__state = -1;             this.2__current = 1;             this.1__state = 1;             return true;         case 1:             this.1__state = -1;             this.2__current = 2;             this.1__state = 2;             return true;         case 2:             this.1__state = -1;             this.2__current = 3;             this.1__state = 3;             return true;         case 3:             this.1__state = -1;             break;     }     return false; } At each stage, the current value of the state is used to determine how far we got, and then we generate the next value which we return after recording the next state. Finally we return false from the MoveNext to signify the end of the sequence. Of course, that example was really simple. The original method body didn't have any local variables. Any local variables need to live between the calls to MoveNext and so they need to be transformed into fields in much the same way that we did in the case of the lambda expression. More complicated MoveNext methods are required to deal with resources that need to be disposed when the iterator finishes, and sometimes the compiler uses a temporary variable to hold the return value. Why all of this explanation? We've implemented the de-compilation of iterators in the current EAP version of Reflector (7). This contrasts with previous version where all you could do was look at the MoveNext method and try to figure out the control flow. There's a fair amount of things we have to do. We have to spot the use of a CompilerGenerated class which implements the Enumerator pattern. We need to go to the class and figure out the fields corresponding to the local variables. We then need to go to the MoveNext method and try to break it into the various possible states and spot the state transitions. We can then take these pieces and put them back together into an object model that uses yield return to show the transition points. After that Reflector can carry on optimising using its usual optimisations. The pattern matching is currently a little too sensitive to changes in the code generation, and we only do a limited analysis of the MoveNext method to determine use of the compiler generated fields. In some ways, it is a pity that iterators are compiled away and there is no metadata that reflects the original intent. Without it, we are always going to dependent on our knowledge of the compiler's implementation. For example, we have noticed that the Async CTP changes the way that iterators are code generated, so we'll have to do some more work to support that. However, with that warning in place, we seem to do a reasonable job of decompiling the iterators that are built into the framework. Hopefully, the EAP will give us a chance to find examples where we don't spot the pattern correctly or regenerate the wrong code, and we can improve things. Please give it a go, and report any problems.

    Read the article

  • Oracle B2B - Synchronous Request Reply

    - by cdwright
    Introduction So first off, let me say I didn't create this demo (although I did modify it some). I got it from a member of the B2B development technical staff. Since it came with only a simple readme file, I thought I would take some time and write a more detailed explanation about how it works. Beginning with Oracle SOA Suite PS5 (11.1.1.6), B2B supports synchronous request reply over http using the b2b/syncreceiver servlet. I’m attaching the demo to this blog which includes a SOA composite archive that needs to be deployed using JDeveloper, a B2B repository with two agreements that need to be deployed using the B2B console, and a test xml file that gets sent to the b2b/syncreceiver servlet using your favorite SOAP test tool (I'm using Firefox Poster here). You can download the zip file containing the demo here. The demo works by sending the sample xml request file (req.xml) to http://<b2bhost>:8001/b2b/syncreceiver using the SOAP test tool.  The syncreceiver servlet keeps the socket connection open between itself and the test tool so that it can synchronously send the reply message back. When B2B receives the inbound request message, it is passed to the SOA composite through the default B2B Fabric binding. A simple reply is created in BPEL and returned to B2B which then sends the message back to the test tool using that same socket connection. I’ll show you the B2B configuration first, then we’ll look at the soa composite. Configuring B2B No additional configuration necessary in order to use the syncreceiver servlet. It is already running when you start SOA. After importing the GC_SyncReqRep.zip repository file into B2B, you’ll have the typical GlobalChips host trading partner and the Acme remote trading partner. Document Management The repository contains two very simple custom XML document definitions called Orders and OrdersResponse. In order to determine the trading partner agreement needed to process the inbound Orders document, you need to know two things about it; what is it and where it came from. So let’s look at how B2B identifies the appropriate document definition for the message. The XSD’s for these two document definitions themselves are not particularly interesting. Whenever you're dealing with custom XML documents, B2B identifies the appropriate document definition for each XML message using an XPath Identification Expression. The expression is entered for each of these document definitions under the document administration tab in the B2B console. The full XPATH expression for the Orders document is  //*[local-name()='shiporder']/*[local-name()='shipto']/*[local-name()='name']/text(). You can see this path in the XSD diagram below and how it uniquely identifies this message. The OrdersReponse document is identified in the same way. The XPath expression for it is //*[local-name()='Response']/*[local-name()='Status']/text(). You can see how it’s path differs uniquely identifying the reply from the request. Trading Partner Profile The trading partner profiles are very simple too. For GlobalChips, a generic identifier is being used to identify the sender of the response document using the host trading partner name. For Acme, a generic identifier is also being used to identify the sender of the inbound request using the remote trading partner name. The document types are added for the remote trading partner as usual. So the remote trading partner Acme is the sender of the Orders document, and it is the receiver of the OrdersResponse document. For the remote trading partner only, there needs to be a dummy channel which gets used in the outbound response agreement. The channel is not actually used. It is just a necessary place holder that needs to be there when creating the agreement. Trading Partner Agreement The agreements are equally simple. There is no validation and translation is not an option for a custom XML document type. For the InboundAgreement (request) the document definition is set to OrdersDef. In the Agreement Parameters section the generic identifiers have been added for the host and remote trading partners. That’s all that is needed for the inbound transaction. For the OutboundAgreement (response), the document definition is set to OrdersResponseDef and the generic identifiers for the two trading partners are added. The remote trading partner dummy delivery channel is also added to the agreement. SOA Composite Import the SOA composite archive into JDeveloper as an EJB JAR file. Open the composite and you should have a project that looks like this. In the composite, open the b2bInboundSyncSvc exposed service and advance through the setup wizard. Select your Application Server Connection and advance to the Operations window. Notice here that the B2B binding is set to Receive. It is not set for Synchronous Request Reply. Continue advancing through the wizard as you normally would and select finish at the end. Now open BPELProcess1 in the composite. The BPEL process is set as a Synchronous Request Reply as you can see below. The while loop is there just to give the process something to do. The actual reply message is prepared in the assignResponseValues assignment followed by an Invoke of the B2B binding. Open the replyResponse Invoke and go to the properties tab. You’ll see that the fromTradingPartnerId, toTradingPartner, documentTypeName, and documentProtocolRevision properties have been set. Testing the Configuration To test the configuration, I used Firefox Poster. Enter the URL for the b2b/syncreceiver servlet and browse for the req.xml file that contains the test request message. In the Headers tab, add the property ‘from’ and give it the value ‘Acme’. This is how B2B will know where the message is coming from and it will use that information along with the document type name to find the right trading partner agreement. Now post the message. You should get back a response with a status of ‘200 OK’. That’s all there is to it.

    Read the article

  • Chart Filtering

    - by Tim Dexter
    Interesting question from a colleague this week. Can you add a filter to a chart to just show a specific set of data? In an RTF template, you need to do a little finagling in the chart definition. In an online template, a couple of clicks and you're done. RTF Build your chart as you would normally to include all the data to start with. Now flip to the Advanced tab to see the code behind the chart. Its not very pretty but with a little effort you can get it looking a little more friendly. Here's my chart showing employees and their salaries. <Graph depthAngle="50" depthRadius="8" seriesEffect="SE_AUTO_GRADIENT"> <LegendArea visible="true"/>  <Title text="Executive Department Only" visible="true" horizontalAlignment="CENTER"/>  <LocalGridData colCount="{count(.//G_2)}" rowCount="1">   <RowLabels>    <Label>SALARY</Label>   </RowLabels>   <ColLabels>    <xsl:for-each select=".//G_2">     <Label><xsl:value-of select="EMP_NAME"/></Label>    </xsl:for-each>   </ColLabels>   <DataValues>    <RowData>     <xsl:for-each select=".//G_2">      <Cell><xsl:value-of select="SALARY"/></Cell>     </xsl:for-each>    </RowData>   </DataValues>  </LocalGridData> </Graph> Note the emboldened text. Its currently grabbing all values in the G_2 level of the data. We can use an XPATH expression to filter the data to the set we want to see. In my case I want to only see the employees that are in the Executive department. My  data is structured thus:   <DATA_DS>     <G_1>         <DEPARTMENT_NAME>Accounting</DEPARTMENT_NAME>         <G_2>             <MANAGER>Higgins</MANAGER>             <EMPLOYEE_ID>206</EMPLOYEE_ID>             <HIRE_DATE>2002-06-07T00:00:00.000-04:00</HIRE_DATE>             <SALARY>8300</SALARY>             <JOB_TITLE>Public Accountant</JOB_TITLE>             <PARAS>11000</PARAS>             <EMP_NAME>William Gietz</EMP_NAME>         </G_2> So the XPATH expression Im going to use to limit the data to the Executive department would be .//G_2[../DEPARTMENT_NAME='Executive'] Note the ../ moves the parser up the XML tree to be able to test the DEPARTMENT_NAME value. I added this XPATH expression to the three instances that need it ColCount, ColLabels and RowData. Its simple enough to do. Testing your XPATH expression is easier to do using a table of data. Please note, as soon as you make changes to the chart code. Going back to the Builder tab, you'll find that everything is grayed out. I recommend you make all the changes you can via the chart dialog before updating the code. Online Template Implementing the filter is much simpler, there is a dialog box to help you out. Add you chart and fill out the various data points you want to show. then hit the Filter item in the ribbon above the chart. That will pop the filter dialog box where you can then add a filter to the chart.   You can add multiple filters if needed and of course you can use the Manage Filters button to re-open and edit the filters. Pretty straightforward stuff!

    Read the article

  • Couldn't match expected type - Haskell Code

    - by wvyar
    I'm trying to learn Haskell, but the small bit of sample code I tried to write is running into a fairly large amount of "Couldn't match expected type" errors. Can anyone give me some guidance as to what I'm doing wrong/how I should go about this? These are the errors, but I'm not really sure how I should be writing my code. toDoSchedulerSimple.hs:6:14: Couldn't match expected type `[t0]' with actual type `IO String' In the return type of a call of `readFile' In a stmt of a 'do' block: f <- readFile inFile In the expression: do { f <- readFile inFile; lines f } toDoSchedulerSimple.hs:27:9: Couldn't match expected type `[a0]' with actual type `IO ()' In the return type of a call of `putStr' In a stmt of a 'do' block: putStr "Enter task name: " In the expression: do { putStr "Enter task name: "; task <- getLine; return inFileArray : task } toDoSchedulerSimple.hs:34:9: Couldn't match expected type `IO ()' with actual type `[a0]' In a stmt of a 'do' block: putStrLn "Your task is: " ++ (inFileArray !! i) In the expression: do { i <- randomRIO (0, (length inFileArray - 1)); putStrLn "Your task is: " ++ (inFileArray !! i) } In an equation for `getTask': getTask inFileArray = do { i <- randomRIO (0, (length inFileArray - 1)); putStrLn "Your task is: " ++ (inFileArray !! i) } toDoSchedulerSimple.hs:41:9: Couldn't match expected type `[a0]' with actual type `IO ()' In the return type of a call of `putStr' In a stmt of a 'do' block: putStr "Enter the task you would like to end: " In the expression: do { putStr "Enter the task you would like to end: "; task <- getLine; filter (endTaskCheck task) inFileArray } toDoSchedulerSimple.hs:60:53: Couldn't match expected type `IO ()' with actual type `[String] -> IO ()' In a stmt of a 'do' block: schedulerSimpleMain In the expression: do { (getTask inFileArray); schedulerSimpleMain } In a case alternative: "get-task" -> do { (getTask inFileArray); schedulerSimpleMain } This is the code itself. I think it's fairly straightforward, but the idea is to run a loop, take input, and perform actions based off of it by calling other functions. import System.Random (randomRIO) import Data.List (lines) initializeFile :: [char] -> [String] initializeFile inFile = do f <- readFile inFile let parsedFile = lines f return parsedFile displayHelp :: IO() displayHelp = do putStrLn "Welcome to To Do Scheduler Simple, written in Haskell." putStrLn "Here are some commands you might find useful:" putStrLn " 'help' : Display this menu." putStrLn " 'quit' : Exit the program." putStrLn " 'new-task' : Create a new task." putStrLn " 'get-task' : Randomly select a task." putStrLn " 'end-task' : Mark a task as finished." putStrLn " 'view-tasks' : View all of your tasks." quit :: IO() quit = do putStrLn "We're very sad to see you go...:(" putStrLn "Come back soon!" createTask :: [String] -> [String] createTask inFileArray = do putStr "Enter task name: " task <- getLine return inFileArray:task getTask :: [String] -> IO() getTask inFileArray = do i <- randomRIO (0, (length inFileArray - 1)) putStrLn "Your task is: " ++ (inFileArray !! i) endTaskCheck :: String -> String -> Bool endTaskCheck str1 str2 = str1 /= str2 endTask :: [String] -> [String] endTask inFileArray = do putStr "Enter the task you would like to end: " task <- getLine return filter (endTaskCheck task) inFileArray viewTasks :: [String] -> IO() viewTasks inFileArray = case inFileArray of [] -> do putStrLn "\nEnd of tasks." _ -> do putStrLn (head inFileArray) viewTasks (tail inFileArray) schedulerSimpleMain :: [String] -> IO() schedulerSimpleMain inFileArray = do putStr "SchedulerSimple> " input <- getLine case input of "help" -> displayHelp "quit" -> quit "new-task" -> schedulerSimpleMain (createTask inFileArray) "get-task" -> do (getTask inFileArray); schedulerSimpleMain "end-task" -> schedulerSimpleMain (endTask inFileArray) "view-tasks" -> do (viewTasks inFileArray); schedulerSimpleMain _ -> do putStrLn "Invalid input."; schedulerSimpleMain main :: IO() main = do putStr "What is the name of the schedule? " sName <- getLine schedulerSimpleMain (initializeFile sName) Thanks, and apologies if this isn't the correct place to be asking such a question.

    Read the article

  • Silverlight Cream for March 23, 2010 -- #818

    - by Dave Campbell
    In this Issue: Max Paulousky, Jeremy Likness, Mark Tucker, Christian Schormann, Page Brooks, Brad Abrams(-2-), Jeff Wilcox, Unnir, Bea Stollnitz, John Papa and Adam Kinney, and Bill Reiss(-2-). Shoutouts: Ashish Shetty posted his material from his MIX10 presentation: Stepping outside the browser with Silverlight 4 Not Silverlight, but dang useful, Karl Shifflett posted a Visual Studio 2010 XAML Editor IntelliSense Presenter Extension Yavor Georgiev posted his MIX10 material: Two samples from today's MIX talk From SilverlightCream.com: GroupBox Sketching Control for WPF applications Using Blend Max Paulousky creates a GroupBox control for SketchFlow for WPF. He includes a link to an example of doing the same for Silverlight. Sequential Asynchronous Workflows in Silverlight using Coroutines Jeremy Likness' latest post begann with a post on the Silverlight.net forum and Rob Eisenburg's MVVM presentation from MIX10 resulting in the use of Wintellect's PowerThreading library (downloadable), and Coroutines. Windows Phone 7 UI Templates Mark Tucker has been putting a lot of thought into WP7 apps and produced 5 templates for building apps, downloadable in PowerPoint format. He's also looking to discuss this concept. Blend 4: About Path Layout, Part I Christian Schormann has a great tutorial up about Expression Blend 4 and path layout ... this is lots of great info, and it's only part 1! Custom Splash Screen for Windows Phone Page Brooks makes very quick work of showing how to add a splash screen to your WP7 app... very nice, Page! Silverlight 4 + RIA Services - Ready for Business: Exposing Data from Entity Framework Brad Abrams next post in the series is is on pulling your data from wherever it lives, and uses a DomainService to shape it for your Silverlight app. Silverlight 4 + RIA Services - Ready for Business: Consuming Data in the Silverlight Client Brad Abrams then discusses consuming that data in a Silverlight app. Not much code involvement at all.. great ROI :) Building Silverlight 3 and Silverlight 4 applications on a .NET 3.5 build machine Jeff Wilcox talks about building Silverlight 3 and Silverlight 4B both on a .NET 3.5 machine. He then adds in the Toolkit, and even WCF RIA Services. Expression Blend 4 - XAML generation tweaks Unnir demonstrates a few changes to Expression Blend 4 that produce more compact XAML. He's also asking for other examples you'd like to see tightened up. How can I sort a hierarchy? Bea Stollnitz posts plausible solutions to sorting data items at each level of a hierarchical UI, with descriptions of why they don't work, followed by the real deal... Silverlight and WPF. Silverlight Training Course (Silverlight 4) John Papa and Adam Kinney have posted a huge body of work to get us up-to-speed on Silverlight 4 -- a WhitePaper, hands-on labs, and an 8-unit course with 25 accompanying videos... geez... Silverlight game development on Windows Phone 7 Bill Reiss has a post up discussing game development on WP7 in general and then discusses his SilverSprite library, with a link to it. XNA or Silverlight for Windows Phone 7 game development? Bill Reiss next discusses the advantage of using Silverlight or XNA for your WP7 game development, and who better to discuss both? Stay in the 'Light! Twitter SilverlightNews | Twitter WynApse | WynApse.com | Tagged Posts | SilverlightCream Join me @ SilverlightCream | Phoenix Silverlight User Group Technorati Tags: Silverlight    Silverlight 3    Silverlight 4    Windows Phone MIX10

    Read the article

  • Silverlight Cream for June 08, 2010 -- #877

    - by Dave Campbell
    In this Issue: Miroslav Miroslavov, Chris Klug, Beau, Christian Schormann(-2-), Dan Wahlin, Pete Brown, Michael S. Scherotter, Philipp Sumi, Andy Wigley, and Phil Middlemiss. Shoutouts: Mark Tucker set about learning Caliburn, and in the process is writing a Caliburn Book: Chapters 1-3 Jesse Liberty has a great link-laden post up about why we should all be learning/using Blend: Why Developers Should, Must, Do Care About The New Expression Blend be sure to read what he says about WP7 development, however! Charlie Kindel announced an Install problem with the Developer Tools CTP Refresh and the WP7 tools... check this out if you're having problems. John Papa has a good post up on the happenings yesterday: Expression Studio 4 Launch of Blend, SketchFlow, Encoder and More! Erik Mork & Company's latest "This Week in Silverlight" is titled First Drop: Prism v4 – First Drop is Available From SilverlightCream.com: Animated navigation between Pages Miroslav Miroslavov has Part 8 of his "Silverlight in Action" series up, detailing cool things from the CompleteIT site... this one is on Animated navigation between pages. Subtitling videos Chris Klug got a gig adding subtitles to videos for Microsoft (sweet) ... and no, not *that* kind of subtitles... read how he approached the final solution. Silverlight Watermark TextBox I'm not sure we can have too many Watermark TextBoxes, and neither does Beau , who sent me a link to this one... give it a dance and decide. Blend 4: Collaborative SketchFlow Feedback with SharePoint With the new Blend release, Christian Schormann has a post up describing the lashup to Sharepoint for sharing Sketchflow and getting feedback. New Utility, Links, and Tutorials for Path-Based Layout Christian Schormann also has a collection of resources for Path-Based Layouts, including a utility "that lets you apply a whole bunch of position-specific effects without having to write any code"... lots of links to resources here. Tales from the Trenches – Building a Real-World Silverlight Line of Business Application Dan Wahlin draws on his recent experience and lays out some of the fun and pitfalls of building LOB apps in Silverlight... WCF, MVVM, slides, and code included WPF (and Silverlight): Choose your Fonts and Text Rendering Options Wisely Pete Brown has a great post up on using fonts wisely across multiple platforms... lots of info and good discussion in the comments as well. Ball Watch USA Remember the awesome watch Michael S. Scherotter did in Silverlight 1 and then converted to Updated Ball Trainmaster Cannonball Watch to Silverlight 2? Well... there's now a contest underfoot and 8 videos to help you get started... all good stuff, and good luck! ... Michael has a post up about the contest: Enter to Win a Ball Watch by Creating One in Silverlight Announcing Sketchables – Rapid Mockup Creation with SketchFlow By way of Jesse Libertyhttp://jesseliberty.com/2010/06/08/why-developers-should-must-do-care-about-the-new-expression-blend/, this is a cool production by Philipp Sumi about a simple mockup framework he's created. Perst - a database for Windows Phone 7 Silverlight I think one of my first comments to Michael Washington back at the MVP Summit 2010 was that we'd need a database engine, and too cool, but we've got one, Andy Wigley discusses Perst in this post... to save you some time, here's the Perst site A Chrome and Glass Theme - Part 7 Phil Middlemiss has part 7 of his great theme-building series up... this time he's giving the accordian control a once-over. Stay in the 'Light! Twitter SilverlightNews | Twitter WynApse | WynApse.com | Tagged Posts | SilverlightCream Join me @ SilverlightCream | Phoenix Silverlight User Group Technorati Tags: Silverlight    Silverlight 3    Silverlight 4    Windows Phone MIX10

    Read the article

  • SQL SERVER – Quiz and Video – Introduction to Hierarchical Query using a Recursive CTE

    - by pinaldave
    This blog post is inspired from SQL Queries Joes 2 Pros: SQL Query Techniques For Microsoft SQL Server 2008 – SQL Exam Prep Series 70-433 – Volume 2.[Amazon] | [Flipkart] | [Kindle] | [IndiaPlaza] This is follow up blog post of my earlier blog post on the same subject - SQL SERVER – Introduction to Hierarchical Query using a Recursive CTE – A Primer. In the article we discussed various basics terminology of the CTE. The article further covers following important concepts of common table expression. What is a Common Table Expression (CTE) Building a Recursive CTE Identify the Anchor and Recursive Query Add the Anchor and Recursive query to a CTE Add an expression to track hierarchical level Add a self-referencing INNER JOIN statement Above six are the most important concepts related to CTE and SQL Server.  There are many more things one has to learn but without beginners fundamentals one can’t learn the advanced  concepts. Let us have small quiz and check how many of you get the fundamentals right. Quiz 1) You have an employee table with the following data. EmpID FirstName LastName MgrID 1 David Kennson 11 2 Eric Bender 11 3 Lisa Kendall 4 4 David Lonning 11 5 John Marshbank 4 6 James Newton 3 7 Sally Smith NULL You need to write a recursive CTE that shows the EmpID, FirstName, LastName, MgrID, and employee level. The CEO should be listed at Level 1. All people who work for the CEO will be listed at Level 2. All of the people who work for those people will be listed at Level 3. Which CTE code will achieve this result? WITH EmpList AS (SELECT Boss.EmpID, Boss.FName, Boss.LName, Boss.MgrID, 1 AS Lvl FROM Employee AS Boss WHERE Boss.MgrID IS NULL UNION ALL SELECT E.EmpID, E.FirstName, E.LastName, E.MgrID, EmpList.Lvl + 1 FROM Employee AS E INNER JOIN EmpList ON E.MgrID = EmpList.EmpID) SELECT * FROM EmpList WITH EmpListAS (SELECT EmpID, FirstName, LastName, MgrID, 1 as Lvl FROM Employee WHERE MgrID IS NULL UNION ALL SELECT EmpID, FirstName, LastName, MgrID, 2 as Lvl ) SELECT * FROM BossList WITH EmpList AS (SELECT EmpID, FirstName, LastName, MgrID, 1 as Lvl FROM Employee WHERE MgrID is NOT NULL UNION SELECT EmpID, FirstName, LastName, MgrID, BossList.Lvl + 1 FROM Employee INNER JOIN EmpList BossList ON Employee.MgrID = BossList.EmpID) SELECT * FROM EmpList 2) You have a table named Employee. The EmployeeID of each employee’s manager is in the ManagerID column. You need to write a recursive query that produces a list of employees and their manager. The query must also include the employee’s level in the hierarchy. You write the following code segment: WITH EmployeeList (EmployeeID, FullName, ManagerName, Level) AS ( –PICK ANSWER CODE HERE ) SELECT EmployeeID, FullName, ” AS [ManagerID], 1 AS [Level] FROM Employee WHERE ManagerID IS NULL UNION ALL SELECT emp.EmployeeID, emp.FullName mgr.FullName, 1 + 1 AS [Level] FROM Employee emp JOIN Employee mgr ON emp.ManagerID = mgr.EmployeeId SELECT EmployeeID, FullName, ” AS [ManagerID], 1 AS [Level] FROM Employee WHERE ManagerID IS NULL UNION ALL SELECT emp.EmployeeID, emp.FullName, mgr.FullName, mgr.Level + 1 FROM EmployeeList mgr JOIN Employee emp ON emp.ManagerID = mgr.EmployeeId Now make sure that you write down all the answers on the piece of paper. Watch following video and read earlier article over here. If you want to change the answer you still have chance. Solution 1) 1 2) 2 Now compare let us check the answers and compare your answers to following answers. I am very confident you will get them correct. Available at USA: Amazon India: Flipkart | IndiaPlaza Volume: 1, 2, 3, 4, 5 Please leave your feedback in the comment area for the quiz and video. Did you know all the answers of the quiz? Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Joes 2 Pros, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

    Read the article

  • Silverlight Cream for June 01, 2010 -- #874

    - by Dave Campbell
    In this Issue: Michael Washington, Alan Beasley and Michael Washington, Miroslav Miroslavov, Max Paulousky, Teresa and Ronald Burger, Laurent Duveau, Tim Heuer, Jeff Brand, Mike Snow, and John Papa. Shoutouts: To pay homage to the Advanced Options button in Expression Blend, Adam Kinney posted: Expression Blend Advanced Options square wallpaper SilverLaw stood his drag and drop ripple on it's head for this one: Silver Soccer - A Case Study for the Flexible Surface Effect (Silverlight 4) From SilverlightCream.com: Expression Blend DataStore - A Powerful Tool For Designers Michael Washington dug into the documentation and with some Microsoft assistance has figured out how to use the SetDataStoreAction in SketchFlow... good tutorial and a game to demonstrate it's use. Windows Phone 7 View Model Style Video Player Alan Beasley and Michael Washington teamed up again to produce a ViewModel-Style Video Player for WP7 ... very nice interface I might add... very detailed tutorial and all the code... oh, and did you notice it uses MVVMLight... on WP7? ... just thought I'd mention that :) Navigation in 3D world of 2D objects In part 7 of the CompleteIT code explenation, Miroslav Miroslavov is discussing some of the very cool animation they did... 3D, moving camera... cool stuff! Search Engine Optimization (SEO) for Silverlight Applications. Part 2 Max Paulousky has part 2 of his Silverlight 4 and SEO series up. In part 2 he's discussing sitemaps and html content providing. He also has good links showing where to submit your sitemaps and information. Mousin’ down the PathListBox Teresa and Ronald Burger (not sure which) has a post up about the PathListBox and how they drew the path that they ended up using, and the code used to enable animation. Dynamically apply and change Theme with the Silverlight Toolkit We've all had fun playing with themes, but Laurent Duveau has an example up of letting your users change the theme at run-time. Microsoft Translator client library for Silverlight Tim Heuer has been playing with the Microsoft Translator for Silverlight and he has a "Works on My Machine" license on what he's making available .. but considering his access to resources... I'd say go for it :) Custom Per-Page Transitions in Windows Phone 7 Jeff Brand has a follow-on to his other WP7 post about page transitions and is now discussing per-page transitions Silverlight Tip of the Day #26 – Changing the Startup Class Mike Snow's latest 'tip' is a little more involved than a tip ... changing the startup class and actually removing (in his example), the page and app classes... code and xaml! I've seen this before but never explained as clean... fun stuff. Behaviors in Blend 4 (Silverlight TV #30) Episode 30 of Silverlight TV (now a tag at Silverlight Cream) finds John Papa talking to Adam Kinney about Behaviors in Blend 4... not only using them but creating a custom one. Stay in the 'Light! Twitter SilverlightNews | Twitter WynApse | WynApse.com | Tagged Posts | SilverlightCream Join me @ SilverlightCream | Phoenix Silverlight User Group Technorati Tags: Silverlight    Silverlight 3    Silverlight 4    Windows Phone MIX10

    Read the article

  • SSIS Technique to Remove/Skip Trailer and/or Bad Data Row in a Flat File

    - by Compudicted
    I noticed that the question on how to skip or bypass a trailer record or a badly formatted/empty row in a SSIS package keeps coming back on the MSDN SSIS Forum. I tried to figure out the reason why and after an extensive search inside the forum and outside it on the entire Web (using several search engines) I indeed found that it seems even thought there is a number of posts and articles on the topic none of them are employing the simplest and the most efficient technique. When I say efficient I mean the shortest time to solution for the fellow developers. OK, enough talk. Let’s face the problem: Typically a flat file (e.g. a comma delimited/CSV) needs to be processed (loaded into a database in most cases really). Oftentimes, such an input file is produced by some sort of an out of control, 3-rd party solution and would come in with some garbage characters and/or even malformed/miss-formatted rows. One such example could be this imaginary file: As you can see several rows have no data and there is an occasional garbage character (1, in this example on row #7). Our task is to produce a clean file that will only capture the meaningful data rows. As an aside, our output/target may be a database table, but for the purpose of this exercise we will simply re-format the source. Let’s outline our course of action to start off: Will use SSIS 2005 to create a DFT; The DFT will use a Flat File Source to our input [bad] flat file; We will use a Conditional Split to process the bad input file; and finally Dump the resulting data to a new [clean] file. Well, only four steps, let’s see if it is too much of work. 1: Start the BIDS and add a DFT to the Control Flow designer (I named it Process Dirty File DFT): 2, and 3: I had added the data viewer to just see what I am getting, alas, surprisingly the data issues were not seen it:   What really is the key in the approach it is to properly set the Conditional Split Transformation. Visually it is: and specifically its SSIS Expression LEN([After CS Column 0]) > 1 The point is to employ the right Boolean expression (yes, the Conditional Split accepts only Boolean conditions). For the sake of this post I re-named the Output Name “No Empty Rows”, but by default it will be named Case 1 (remember to drag your first column into the expression area)! You can close your Conditional Split now. The next part will be crucial – consuming the output of our Conditional Split. Last step - #4: Add a Flat File Destination or any other one you need. Click on the Conditional Split and choose the green arrow to drop onto the target. When you do so make sure you choose the No Empty Rows output and NOT the Conditional Split Default Output. Make the necessary mappings. At this point your package must look like: As the last step will run our package to examine the produced output file. F5: and… it looks great!

    Read the article

  • Organising levels / rooms in a MUD-style text based world

    - by Polynomial
    I'm thinking of writing a small text-based adventure game, but I'm not particularly sure how I should design the world from a technical standpoint. My first thought is to do it in XML, designed something like the following. Apologies for the huge pile of XML, but I felt it important to fully explain what I'm doing. <level> <start> <!-- start in kitchen with empty inventory --> <room>Kitchen</room> <inventory></inventory> </start> <rooms> <room> <name>Kitchen</name> <description>A small kitchen that looks like it hasn't been used in a while. It has a table in the middle, and there are some cupboards. There is a door to the north, which leads to the garden.</description> <!-- IDs of the objects the room contains --> <objects> <object>Cupboards</object> <object>Knife</object> <object>Batteries</object> </objects> </room> <room> <name>Garden</name> <description>The garden is wild and full of prickly bushes. To the north there is a path, which leads into the trees. To the south there is a house.</description> <objects> </objects> </room> <room> <name>Woods</name> <description>The woods are quite dark, with little light bleeding in from the garden. It is eerily quiet.</description> <objects> <object>Trees01</object> </objects> </room> </rooms> <doors> <!-- a door isn't necessarily a door. each door has a type, i.e. "There is a <type> leading to..." from and to are references the rooms that this door joins. direction specifies the direction (N,S,E,W,Up,Down) from <from> to <to> --> <door> <type>door</type> <direction>N</direction> <from>Kitchen</from> <to>Garden</to> </door> <door> <type>path</type> <direction>N</direction> <from>Garden</type> <to>Woods</type> </door> </doors> <variables> <!-- variables set by actions --> <variable name="cupboard_open">0</variable> </variables> <objects> <!-- definitions for objects --> <object> <name>Trees01</name> <displayName>Trees</displayName> <actions> <!-- any actions not defined will show the default failure message --> <action> <command>EXAMINE</command> <message>The trees are tall and thick. There aren't any low branches, so it'd be difficult to climb them.</message> </action> </actions> </object> <object> <name>Cupboards</name> <displayName>Cupboards</displayName> <actions> <action> <!-- requirements make the command only work when they are met --> <requirements> <!-- equivilent of "if(cupboard_open == 1)" --> <require operation="equal" value="1">cupboard_open</require> </requirements> <command>EXAMINE</command> <!-- fail message is the message displayed when the requirements aren't met --> <failMessage>The cupboard is closed.</failMessage> <message>The cupboard contains some batteires.</message> </action> <action> <requirements> <require operation="equal" value="0">cupboard_open</require> </requirements> <command>OPEN</command> <failMessage>The cupboard is already open.</failMessage> <message>You open the cupboard. It contains some batteries.</message> <!-- assigns is a list of operations performed on variables when the action succeeds --> <assigns> <assign operation="set" value="1">cupboard_open</assign> </assigns> </action> <action> <requirements> <require operation="equal" value="1">cupboard_open</require> </requirements> <command>CLOSE</command> <failMessage>The cupboard is already closed.</failMessage> <message>You closed the cupboard./message> <assigns> <assign operation="set" value="0">cupboard_open</assign> </assigns> </action> </actions> </object> <object> <name>Batteries</name> <displayName>Batteries</displayName> <!-- by setting inventory to non-zero, we can put it in our bag --> <inventory>1</inventory> <actions> <action> <requirements> <require operation="equal" value="1">cupboard_open</require> </requirements> <command>GET</command> <!-- failMessage isn't required here, it'll just show the usual "You can't see any <blank>." message --> <message>You picked up the batteries.</message> </action> </actions> </object> </objects> </level> Obviously there'd need to be more to it than this. Interaction with people and enemies as well as death and completion are necessary additions. Since the XML is quite difficult to work with, I'd probably create some sort of world editor. I'd like to know if this method has any downfalls, and if there's a "better" or more standard way of doing it.

    Read the article

  • Simple MVVM Walkthrough – Refactored

    - by Sean Feldman
    JR has put together a good introduction post into MVVM pattern. I love kick start examples that serve the purpose well. And even more than that I love examples that also can pass the real world projects check. So I took the sample code and refactored it slightly for a few aspects that a lot of developers might raise a brow. Michael has mentioned model (entity) visibility from view. I agree on that. A few other items that don’t settle are using property names as string (magical strings) and Saver class internal casting of a parameter (custom code for each Saver command). Fixing a property names usage is a straight forward exercise – leverage expressions. Something simple like this would do the initial job: class PropertyOf<T> { public static string Resolve(Expression<Func<T, object>> expression) { var member = expression.Body as MemberExpression; return member.Member.Name; } } With this, refactoring of properties names becomes an easy task, with confidence that an old property name string will not get left behind. An updated Invoice would look like this: public class Invoice : INotifyPropertyChanged { private int id; private string receiver; public event PropertyChangedEventHandler PropertyChanged; private void OnPropertyChanged(string propertyName) { if (PropertyChanged != null) { PropertyChanged(this, new PropertyChangedEventArgs(propertyName)); } } public int Id { get { return id; } set { if (id != value) { id = value; OnPropertyChanged(PropertyOf<Invoice>.Resolve(x => x.Id)); } } } public string Receiver { get { return receiver; } set { receiver = value; OnPropertyChanged(PropertyOf<Invoice>.Resolve(x => x.Receiver)); } } } For the saver, I decided to change it a little so now it becomes a “view-model agnostic” command, one that can be used for multiple commands/view-models. Updated Saver code now accepts an action at construction time and executes that action. No more black magic internal class Command : ICommand { private readonly Action executeAction; public Command(Action executeAction) { this.executeAction = executeAction; } public bool CanExecute(object parameter) { return true; } public event EventHandler CanExecuteChanged; public void Execute(object parameter) { // no more black magic executeAction(); } } Change in InvoiceViewModel is instantiation of Saver command and execution action for the specific command. public ICommand SaveCommand { get { if (saveCommand == null) saveCommand = new Command(ExecuteAction); return saveCommand; } set { saveCommand = value; } } private void ExecuteAction() { DisplayMessage = string.Format("Thanks for creating invoice: {0} {1}", Invoice.Id, Invoice.Receiver); } This way internal knowledge of InvoiceViewModel remains in InvoiceViewModel and Command (ex-Saver) is view-model agnostic. Now the sample is not only a good introduction, but also has some practicality in it. My 5 cents on the subject. Sample code MvvmSimple2.zip

    Read the article

  • Sitting Pretty

    - by Phil Factor
    Guest Editorial for Simple-Talk IT Pro newsletter'DBAs and SysAdmins generally prefer an expression of calmness under adversity. It is a subtle trick, and requires practice in front of a mirror to get it just right. Too much adversity and they think you're not coping; too much calmness and they think you're under-employed' I dislike the term 'avatar', when used to describe a portrait photograph. An avatar, in the sense of a picture, is merely the depiction of one's role-play alter-ego, often a ridiculous bronze-age deity. However, professional image is important. The choice and creation of online photos has an effect on the way your message is received and it is important to get that right. It is fine to use that photo of you after ten lagers on holiday in an Ibiza nightclub, but what works on Facebook looks hilarious on LinkedIn. My splendid photograph that I use online was done by a professional photographer at great expense and I've never had the slightest twinge of regret when I remember how much I paid for it. It is me, but a more pensive and dignified edition, oozing trust and wisdom. One gasps at the magical skill that a professional photographer can conjure up, without digital manipulation, to make the best of a derisory noggin (ed: slang for a head). Even if he had offered to depict me as a semi-naked, muscle-bound, sword-wielding hero, I'd have demurred. No, any professional person needs a carefully cultivated image that looks right. I'd never thought of using that profile shot, though I couldn't help noticing the photographer flinch slightly when he first caught sight of my face. There is a problem with using an avatar. The use of a single image doesn't express the appropriate emotion. At the moment, it is weird to see someone with a laughing portrait writing something solemn. A neutral cast to the face, somewhat like a passport photo, is probably the best compromise. Actually, the same is true of a working life in IT. One of the first skills I learned was not to laugh at managers, but, instead, to develop a facial expression that promoted a sense of keenness, energy and respect. Every profession has its own preferred facial cast. A neighbour of mine has the natural gift of a face that displays barely repressed grief. Though he is characteristically cheerful, he earns a remarkable income as a pallbearer. DBAs and SysAdmins generally prefer an expression of calmness under adversity. It is a subtle trick, and requires practice in front of a mirror to get it just right. Too much adversity and they think you're not coping; too much calmness and they think you're under-employed. With an appropriate avatar, you could do away with a lot of the need for 'smilies' to give clues as to the meaning of what you've written on forums and blogs. If you had a set of avatars, showing the full gamut of human emotions expressible in writing: Rage, fear, reproach, joy, ebullience, apprehension, exasperation, dissembly, irony, pathos, euphoria, remorse and so on. It would be quite a drop-down list on forums, but given the vast prairies of space on the average hard drive, who cares? It would cut down on the number of spats in Forums just as long as one picks the right avatar. As an unreconstructed geek, I find it hard to admit to the value of image in the workplace, but it is true. Just as we use professionals to tidy up and order our CVs and job applications, we should employ experts to enhance our professional image. After all you don't perform surgery or dentistry on yourself do you?

    Read the article

  • Introduction to WebCenter Personalization: &ldquo;The Conductor&rdquo;

    - by Steve Pepper
    There are some new faces in the town of WebCenter with the latest 11g PS3 release.  A new component has introduced itself as "Oracle WebCenter Personalization", a.k.a WCP, to simplify delivery of a personalized experience and content to end users.  This posting reviews one of the primary components within WCP: "The Conductor". The Conductor: This ain't just an ordinary cloud... One of the founding principals behind WebCenter Personalization was to provide an open client-side API that remains independent of the technology invoking it, in addition to independence from the architecture running it.  The Conductor delivers this, and much, much more. The Conductor is the engine behind WebCenter Personalization that allows flow-based documents, called "Scenarios", to be managed and executed on the server-side through a well published and RESTful api.      The Conductor also supports an extensible model for custom provider integration that can be easily invoked within a Scenario to promote seamless integration with existing business assets. Introducing the Scenario Conductor Scenarios are declarative offline-authored documents using the custom Personalization JDeveloper bundle included with WebCenter.  A Scenario contains one (or more) statements that can: Create variables that are scoped to the current execution context Iterate over collections, or loop until a specific condition is met Execute one or more statements when a condition is met Invoke other scenarios that exist within the same namespace Invoke a data provider that integrates with custom applications Once a variable is assigned within the Scenario's execution context, it can be referenced anywhere within the same Scenario using the common Expression Language syntax used in J2EE web containers. Scenarios are then published and tested to the Integrated WebLogic Server domain, or published remotely to other domains running WebCenter Personalization. Various Client-side Models The Conductor server API is built upon RESTful services that support a wide variety of clients able to communicate over HTTP.  The Conductor supports the following client-side models: REST:  Popular browser-based languages can be used to manage and execute Conductor Scenarios.  There are other public methods to retrieve configured provider metadata that can be used by custom applications. The Conductor currently supports XML and JSON for it's API syntax. Java: WebCenter Personalization delivers a robust and light-weight java client with the popular Jersey framework as it's foundation.  It has never been easier to write a remote java client to manage remote RESTful services. Expression Language (EL): Allow the results of Scenario execution to control your user interface or embed personalized content using the session-scoped managed bean.  The EL client can also be used in straight JSP pages with minimal configuration. Extensible Provider Framework The Conductor supports a pluggable provider framework for integrating custom code with Scenario execution.  There are two types of providers supported by the Conductor: Function Provider: Function Providers are simple java annotated classes with static methods that are meant to be served as utilities.  Some common uses would include: object creation or instantiation, data transformation, and the like.  Function Providers can be invoked using the common EL syntax from variable assignments, conditions, and loops. For example:  ${myUtilityClass:doStuff(arg1,arg2))} If you are familiar with EL Functions, Function Providers are based on the same concept. Data Provider: Like Function Providers, Data Providers are annotated java classes, but they must adhere to a much more strict object model.  Data Providers have access to a wealth of Conductor services, such as: Access to namespace-scoped configuration API that can be managed by Oracle Enterprise Manager, Scenario execution context for expression resolution, and more.  Oracle ships with three out-of-the-box data providers that supports integration with: Standardized Content Servers(CMIS),  Federated Profile Properties through the Properties Service, and WebCenter Activity Graph. Useful References If you are looking to immediately get started writing your own application using WebCenter Personalization Services, you will find the following references helpful in getting you on your way: Personalizing WebCenter Applications Authoring Personalized Scenarios in JDeveloper Using Personalization APIs Externally Implementing and Calling Function Providers Implementing and Calling Data Providers

    Read the article

  • Why is x=x++ undefined?

    - by ugoren
    It's undefined because the it modifies x twice between sequence points. The standard says it's undefined, therefore it's undefined. That much I know. But why? My understanding is that forbidding this allows compilers to optimize better. This could have made sense when C was invented, but now seems like a weak argument. If we were to reinvent C today, would we do it this way, or can it be done better? Or maybe there's a deeper problem, that makes it hard to define consistent rules for such expressions, so it's best to forbid them? So suppose we were to reinvent C today. I'd like to suggest simple rules for expressions such as x=x++, which seem to me to work better than the existing rules. I'd like to get your opinion on the suggested rules compared to the existing ones, or other suggestions. Suggested Rules: Between sequence points, order of evaluation is unspecified. Side effects take place immediately. There's no undefined behavior involved. Expressions evaluate to this value or that, but surely won't format your hard disk (strangely, I've never seen an implementation where x=x++ formats the hard disk). Example Expressions x=x++ - Well defined, doesn't change x. First, x is incremented (immediately when x++ is evaluated), then it's old value is stored in x. x++ + ++x - Increments x twice, evaluates to 2*x+2. Though either side may be evaluated first, the result is either x + (x+2) (left side first) or (x+1) + (x+1) (right side first). x = x + (x=3) - Unspecified, x set to either x+3 or 6. If the right side is evaluated first, it's x+3. It's also possible that x=3 is evaluated first, so it's 3+3. In either case, the x=3 assignment happens immediately when x=3 is evaluated, so the value stored is overwritten by the other assignment. x+=(x=3) - Well defined, sets x to 6. You could argue that this is just shorthand for the expression above. But I'd say that += must be executed after x=3, and not in two parts (read x, evaluate x=3, add and store new value). What's the Advantage? Some comments raised this good point. It's not that I'm after the pleasure of using x=x++ in my code. It's a strange and misleading expression. What I want is to be able to understand complicated expressions. Normally, a complicated expression is no more than the sum of its parts. If you understand the parts and the operators combining them, you can understand the whole. C's current behavior seems to deviate from this principle. One assignment plus another assignment suddenly doesn't make two assignments. Today, when I look at x=x++, I can't say what it does. With my suggested rules, I can, by simply examining its components and their relations.

    Read the article

  • Relation between [[Prototype]] and prototype in JavaScript

    - by Claudiu
    From http://www.jibbering.com/faq/faq_notes/closures.html : Note: ECMAScript defines an internal [[prototype]] property of the internal Object type. This property is not directly accessible with scripts, but it is the chain of objects referred to with the internal [[prototype]] property that is used in property accessor resolution; the object's prototype chain. A public prototype property exists to allow the assignment, definition and manipulation of prototypes in association with the internal [[prototype]] property. The details of the relationship between to two are described in ECMA 262 (3rd edition) and are beyond the scope of this discussion. What are the details of the relationship between the two? I've browsed through ECMA 262 and all I've read there is stuff like: The constructor’s associated prototype can be referenced by the program expression constructor.prototype, Native ECMAScript objects have an internal property called [[Prototype]]. The value of this property is either null or an object and is used for implementing inheritance. Every built-in function and every built-in constructor has the Function prototype object, which is the initial value of the expression Function.prototype Every built-in prototype object has the Object prototype object, which is the initial value of the expression Object.prototype (15.3.2.1), as the value of its internal [[Prototype]] property, except the Object prototype object itself. From this all I gather is that the [[Prototype]] property is equivalent to the prototype property for pretty much any object. Am I mistaken?

    Read the article

  • How can I access the group of a linq group-by query from a nested repeater control?

    - by Duke
    I'm using a linq group by query (with two grouping parameters) and would like to use the resulting data in a nested repeater. var dateGroups = from row in data.AsEnumerable() group row by new { StartDate = row["StartDate"], EndDate = row["EndDate"] }; "data" is a DataTable from an SqlDataAdapter-filled DataSet. "dateGroups" is used in the parent repeater, and I can access the group keys using Eval("key.StartDate") and Eval("key.EndDate"). Since dateGroups actually contains all the data rows grouped neatly by Start/End date, I'd like to access those rows to display the data in a child repeater. To what would I set the child repeater's DataSource? I have tried every expression in markup I could think of; I think the problem is that I'm trying to access an anonymous member (and I don't know how.) In case it doesn't turn out to be obvious, what would be the expression to access the elements in each iteration of the child repeater? Is there an expression that would let me set the DataSource in the markup, or will it have to be in the codebehind on some event in the parent repeater?

    Read the article

  • Good grammar for date data type for recursive descent parser LL(1)

    - by Totophil
    I'm building a custom expression parser and evaluator for production enviroment to provide a limited DSL to the users. The parser itself as the DSL, need to be simple. The parser is going to be built in an exotic language that doesn't support dynamic expression parsing nor has any parser generator tools available. My decision is to go for recursive descent approach with LL(1) grammar, so that even programmers with no previous experience in evaluating expression could quickly learn how the code works. It has to handle mixed expressions made up of several data types: decimals, percentages, strings and dates. And dates in the format of dd/mm/yyyy are easy to confuse with a string of devision ops. Is where a good solution to this problem? My own solution that is aimed at keeping the parser simple involves prefixing dates with a special symbol, let's say apostrophe: <date> ::= <apostr><digit><digit>/<digit><digit>/<digit><digit><digit><digit> <apostr> ::= ' <digit> ::= '0'..'9'

    Read the article

  • Why does division yield a vastly different result than multiplication by a fraction in floating points.

    - by Avram
    I understand why floating point numbers can't be compared, and know about the mantissa and exponent binary representation, but I'm no expert and today I came across something I don't get: Namely lets say you have something like: float denominator, numerator, resultone, resulttwo; resultone = numerator / denominator; float buff = 1 / denominator; resulttwo = numerator * buff; To my knowledge different flops can yield different results and this is not unusual. But in some edge cases these two results seem to be vastly different. To be more specific in my GLSL code calculating the Beckmann facet slope distribution for the Cook-Torrance lighitng model: float a = 1 / (facetSlopeRMS * facetSlopeRMS * pow(clampedCosHalfNormal, 4)); float b = clampedCosHalfNormal * clampedCosHalfNormal - 1.0; float c = facetSlopeRMS * facetSlopeRMS * clampedCosHalfNormal * clampedCosHalfNormal; facetSlopeDistribution = a * exp(b/c); yields very very different results to float a = (facetSlopeRMS * facetSlopeRMS * pow(clampedCosHalfNormal, 4)); facetDlopeDistribution = exp(b/c) / a; Why does it? The second form of the expression is problematic. If I say try to add the second form of the expression to a color I get blacks, even though the expression should always evaluate to a positive number. Am I getting an infinity? A NaN? if so why?

    Read the article

  • Programming R/Sweave for proper \Sexpr output

    - by deoksu
    Hi I'm having a bit of a problem programming R for Sweave, and the #rstats twitter group often points here, so I thought I'd put this question to the SO crowd. I'm an analyst- not a programmer- so go easy on me my first post. Here's the problem: I am drafting a survey report in Sweave with R and would like to report the marginal returns in line using \Sexpr{}. For example, rather than saying: Only 14% of respondents said 'X'. I want to write the report like this: Only \Sexpr{p.mean(variable)}$\%$ of respondents said 'X'. The problem is that Sweave() converts the results of the expression in \Sexpr{} to a character string, which means that the output from expression in R and the output that appears in my document are different. For example, above I use the function 'p.mean': p.mean<- function (x) {options(digits=1) mmm<-weighted.mean(x, weight=weight, na.rm=T) print(100*mmm) } In R, the output looks like this: p.mean(variable) >14 but when I use \Sexpr{p.mean(variable)}, I get an unrounded character string (in this case: 13.5857142857143) in my document. I have tried to limit the output of my function to 'digits=1' in the global environment, in the function itself, and and in various commands. It only seems to contain what R prints, not the character transformation that is the result of the expression and which eventually prints in the LaTeX file. as.character(p.mean(variable)) >[1] 14 >[1] "13.5857142857143" Does anyone know what I can do to limit the digits printed in the LaTeX file, either by reprogramming the R function or with a setting in Sweave or \Sexpr{}? I'd greatly appreciate any help you can give. Thanks, David

    Read the article

  • Regex For Finding Ctypes with Int32

    - by Stefan H
    (Hey all, I am looking for a little regex help... I am trying to find all CType(expression,Int32) s and replace them with CInt(expression) This, however, is proving quite difficult, considering there could be a nested Ctype(expression, Int32) within the regex match. Does anyone have any ideas for how to best go about doing this? Here is what I have now: Dim str As String = "CType((original.Width * CType((targetSize / CType(original.Height, Single)), Single)), Int32)" Dim exp As New Regex("CType\((.+), Int32\)") str = exp.Replace(str, "CInt($1)") But this will match the entire string and replace it. I was thinking of doing a recursive function to find the outer most match, and then work inwards, but that still presents a problem with things like CType(replaceChars(I), Int32)), Chr(CType(replacementChars(I), Int32) Any tips would be appreciated. Input returnString.Replace(Chr(CType(replaceChars(I), Int32)), Chr(CType(replacementChars(I), Int32))) Output: returnString.Replace(Chr(CInt(replaceChars(I))),Chr(CInt(replacementChars(I)))) Edit: Been working on it a little more and have a recursive function that I'm still working out the kinks in. Recursion + regex. it kinda hurts. Private Function FindReplaceCInts(ByVal strAs As String) As String System.Console.WriteLine(String.Format("Testing : {0}", strAs)) Dim exp As New Regex("CType\((.+), Int32\)") If exp.Match(strAs).Success Then For Each match As Match In exp.Matches(strAs) If exp.Match(match.Value.Substring(2)).Success Then Dim replaceT As String = match.Value.Substring(2) Dim Witht As String = FindReplaceCInts(match.Value.Substring(2)) System.Console.WriteLine(strAs.IndexOf(replaceT)) strAs.Replace(replaceT, Witht) End If Next strAs = exp.Replace(strAs, "CInt($1)") End If Return strAs End Function Cheers,

    Read the article

< Previous Page | 77 78 79 80 81 82 83 84 85 86 87 88  | Next Page >