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  • MVC 3 beta + Dependency Resolver + Unity = got problem

    - by drsim
    Hi everyone. I'm tried to use Dependency Resolver with Unity, and got some problem when my Controller creating. Here example of controller: public class AccountController : Controller { private readonly ICourseService _courseService; public AccountController(ICourseService courseService) { _courseService = courseService; } } But, when Controller try to create - i got an exception "No parameterless constructor defined for this object." I even try to add default constructor for this controller, but courseService didn't create. Also try to add property with [Dependency] attribute - nothing happened. Here is Dependency Resolver class: public class UnityDependencyResolver : IDependencyResolver { private readonly IUnityContainer _container; public UnityDependencyResolver(IUnityContainer container) { _container = container; } public object GetService(Type serviceType) { return _container.IsRegistered(serviceType) ? _container.Resolve(serviceType) : null; } public IEnumerable<object> GetServices(Type serviceType) { return _container.IsRegistered(serviceType) ? _container.ResolveAll(serviceType) : new List<object>(); } } and Global.asax.cs: protected void Application_Start() { AreaRegistration.RegisterAllAreas(); RegisterGlobalFilters(GlobalFilters.Filters); RegisterRoutes(RouteTable.Routes); var container = new UnityContainer(); container.RegisterType<ICourseService, CourseService>(); DependencyResolver.SetResolver(new UnityDependencyResolver(container)); } Can anyone help me ?

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  • Logging errors in ASP.NET (MVC) through the Custom Error

    - by Alex
    In my web.config I have the following: <customErrors mode="RemoteOnly" defaultRedirect="/error.aspx"/> When an error occurs, the user is redirected to /error.aspx?aspxerrorpath=/somepage where I can get user's name, name of the page, date, but... I can't get the error message! I can get it via the OnException method, but then I won't be able to get the name of the page which is very important for me. How can I get both the page and the error message?

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  • How to disable current page links in ASP.NET MVC?

    - by rem
    I'm investigating ASP.NET MVC now and noticed that in ASP.NET MVC application, which is created by Visual Studio by default, links "Home" and "About" are staying active when the user is on "Home" and "About" page correspondingly, and after clicking on the current page link page is reloading itself. What is the correct approach to disable link which points to the page, a user is already on? How to do it without violating ASP.NET MVC approach?

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  • ViewContext.Writer() doesn't exist in ASP.NET MVC 1.0?

    - by DaveDev
    I have the following code in an ASP.NET MVC 2 application. internal TextWriter _writer; // some stuff _writer = _viewContext.Writer; _writer.Write(_tag.ToString(TagRenderMode.EndTag)); I tried to move it to MVC 1 and now it doesn't build any more. I'm getting this error: 'System.Web.Mvc.ViewContext' does not contain a definition for 'Writer' Can someone point out how I can resolve this?

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  • asp.net-mvc: javascript caching

    - by Omu
    I'm thinking whether it makes sense in order to increase the speed of the website to do some strategy of caching the js files that are being included ? one idea that I have is to do something like this: [OutputCache(Location = OutputCacheLocation.Any, Duration = 3600)] public JsController : Controller public ActionResult JQuery() { //I would have a ascx with the entire jquery script inside return View(); } and on the site.master: <%=Html.RenderAction("JQuery","JsController");

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  • MVC and Checkboxes...leaves a bit to be desired

    - by Josh
    Here is my problem. I have a list of models that are displayed to the user. On the left is a checkbox for each model to indicate that the user wants to choose this model (in this case, we're building products a user can add to their shopping cart). The model has no concept of being chosen...it strictly has information about the product in question. I've talked with a few other developers after having gone through and the best I could come up with is getting the formcollection and string parsing the key values to determine whether the checkbox is checked or not. This doesn't seem ideal. I was thinking there would be something more strongly bound, but I can't figure out a way to do it. I tried creating another model that had a boolean property to represent being checked and a property of the model and passing a list of that model type to the view and creating a ActionResult on the controller that accepts a list of the new model / checked property, but it comes back null. Am I just thinking too much like web forms and should just continue on with parsing checkbox values?

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  • asp.net mvc create view

    - by mazhar
    I have created a Create view.Now the thing is that I want to throw all the fields from the create view into the data plus two other fields which are not on the view which are created date and created by .How will I do that?

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  • asp.net mvc, jquery dialog + select + getJson (different results in ff, ie and chrome)

    - by vbobruisk
    Hi everybody. i'm using jquery 1.3.2, and have a problem in situatsuin where i fill select via getJson $.each(data, function() { $("#select_elem").append("<option value='"+this.Value+"'>" + this.Value + "</option>"); }); and after, when i try to get selected value : var sel_val = $("#select_elem"); alert(sel_val.val()); in IE it works, in FF it always shows the first value in list, in chrome it's always null. is there any way to fix this? Thank You !

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  • Set title to a div in mvc

    - by user281180
    I have the following code, but it`s giving me errors <div id="ChangePassword" title="Change password for "&<%=item.Name%>> <%Html.RenderPartial("PasswordDetails", Model); %> </div> I need to display the name in the title. How can I do that?

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  • MVC can't find my Areas page

    - by Steven
    I created an Area in my application named Admin. It's pretty basic, looks like this: Areas Admin Controllers CompaniesController.cs Models Views Companies Index.aspx AdminAreaRegistration.cs When I try to view my Index page by going to /Admin/Companies, I get a "The resource cannot be found" message. I find it weird that I don't get any sort of error message. I'm not sure what's going on here, has anyone come across this?

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  • MVC -DropDownList - Categories - SubCategories

    - by Frajer
    In my database I have tbales: categoreis and SubCategoreis. I would Like to create one Dropdownlist containg both of these. Something like: «Välj» <option value='1000' style='background-color:#dcdcc3;font-weight:bold;' id='cat1000' > -- FORDON -- /// this is from Categoreis Table </option> <option value='1020' id='cat1020' > Bilar /// this is from SubCategoreis </option> <option value='1040' id='cat1040' > Bildelar & Biltillbehör /// this is from Categoreis </option> <option value='1060' id='cat1060' > Båtar /// this is from Categoreis </option> <option value='1080' id='cat1080' > Båtdelar & tillbehör /// this is from Categoreis </option> Any samples how I could solve this? should I use Helpers or MVCUsercontrol??? I think that caching is importatnt in this case.Help me out ! Thanks!!

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  • Can i do this in javascript ?(ASP.NET MVC)

    - by user1710716
    <script type="text/javascript"> function CheckData(e) { var form = e.form; var dataItem = e.dataItem; var r = <%=Session["count"] %>; var s = []; var t = []; for (i=1;i<r;i++) { s.push(<%=Session["level"+i] %>; } for(i=1;i<r;i++) { t.push(<%=Session["level"+i+"val"] %> } if(e.mode="edit") { } } </script> I try to combind session in to variable in JavaScript but my session has dynamic session this code get error when I try to build.

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  • Using LINQ Distinct: With an Example on ASP.NET MVC SelectListItem

    - by Joe Mayo
    One of the things that might be surprising in the LINQ Distinct standard query operator is that it doesn’t automatically work properly on custom classes. There are reasons for this, which I’ll explain shortly. The example I’ll use in this post focuses on pulling a unique list of names to load into a drop-down list. I’ll explain the sample application, show you typical first shot at Distinct, explain why it won’t work as you expect, and then demonstrate a solution to make Distinct work with any custom class. The technologies I’m using are  LINQ to Twitter, LINQ to Objects, Telerik Extensions for ASP.NET MVC, ASP.NET MVC 2, and Visual Studio 2010. The function of the example program is to show a list of people that I follow.  In Twitter API vernacular, these people are called “Friends”; though I’ve never met most of them in real life. This is part of the ubiquitous language of social networking, and Twitter in particular, so you’ll see my objects named accordingly. Where Distinct comes into play is because I want to have a drop-down list with the names of the friends appearing in the list. Some friends are quite verbose, which means I can’t just extract names from each tweet and populate the drop-down; otherwise, I would end up with many duplicate names. Therefore, Distinct is the appropriate operator to eliminate the extra entries from my friends who tend to be enthusiastic tweeters. The sample doesn’t do anything with the drop-down list and I leave that up to imagination for what it’s practical purpose could be; perhaps a filter for the list if I only want to see a certain person’s tweets or maybe a quick list that I plan to combine with a TextBox and Button to reply to a friend. When the program runs, you’ll need to authenticate with Twitter, because I’m using OAuth (DotNetOpenAuth), for authentication, and then you’ll see the drop-down list of names above the grid with the most recent tweets from friends. Here’s what the application looks like when it runs: As you can see, there is a drop-down list above the grid. The drop-down list is where most of the focus of this article will be. There is some description of the code before we talk about the Distinct operator, but we’ll get there soon. This is an ASP.NET MVC2 application, written with VS 2010. Here’s the View that produces this screen: <%@ Page Language="C#" MasterPageFile="~/Views/Shared/Site.Master" Inherits="System.Web.Mvc.ViewPage<TwitterFriendsViewModel>" %> <%@ Import Namespace="DistinctSelectList.Models" %> <asp:Content ID="Content1" ContentPlaceHolderID="TitleContent" runat="server">     Home Page </asp:Content><asp:Content ID="Content2" ContentPlaceHolderID="MainContent" runat="server">     <fieldset>         <legend>Twitter Friends</legend>         <div>             <%= Html.DropDownListFor(                     twendVM => twendVM.FriendNames,                     Model.FriendNames,                     "<All Friends>") %>         </div>         <div>             <% Html.Telerik().Grid<TweetViewModel>(Model.Tweets)                    .Name("TwitterFriendsGrid")                    .Columns(cols =>                     {                         cols.Template(col =>                             { %>                                 <img src="<%= col.ImageUrl %>"                                      alt="<%= col.ScreenName %>" />                         <% });                         cols.Bound(col => col.ScreenName);                         cols.Bound(col => col.Tweet);                     })                    .Render(); %>         </div>     </fieldset> </asp:Content> As shown above, the Grid is from Telerik’s Extensions for ASP.NET MVC. The first column is a template that renders the user’s Avatar from a URL provided by the Twitter query. Both the Grid and DropDownListFor display properties that are collections from a TwitterFriendsViewModel class, shown below: using System.Collections.Generic; using System.Web.Mvc; namespace DistinctSelectList.Models { /// /// For finding friend info on screen /// public class TwitterFriendsViewModel { /// /// Display names of friends in drop-down list /// public List FriendNames { get; set; } /// /// Display tweets in grid /// public List Tweets { get; set; } } } I created the TwitterFreindsViewModel. The two Lists are what the View consumes to populate the DropDownListFor and Grid. Notice that FriendNames is a List of SelectListItem, which is an MVC class. Another custom class I created is the TweetViewModel (the type of the Tweets List), shown below: namespace DistinctSelectList.Models { /// /// Info on friend tweets /// public class TweetViewModel { /// /// User's avatar /// public string ImageUrl { get; set; } /// /// User's Twitter name /// public string ScreenName { get; set; } /// /// Text containing user's tweet /// public string Tweet { get; set; } } } The initial Twitter query returns much more information than we need for our purposes and this a special class for displaying info in the View.  Now you know about the View and how it’s constructed. Let’s look at the controller next. The controller for this demo performs authentication, data retrieval, data manipulation, and view selection. I’ll skip the description of the authentication because it’s a normal part of using OAuth with LINQ to Twitter. Instead, we’ll drill down and focus on the Distinct operator. However, I’ll show you the entire controller, below,  so that you can see how it all fits together: using System.Linq; using System.Web.Mvc; using DistinctSelectList.Models; using LinqToTwitter; namespace DistinctSelectList.Controllers { [HandleError] public class HomeController : Controller { private MvcOAuthAuthorization auth; private TwitterContext twitterCtx; /// /// Display a list of friends current tweets /// /// public ActionResult Index() { auth = new MvcOAuthAuthorization(InMemoryTokenManager.Instance, InMemoryTokenManager.AccessToken); string accessToken = auth.CompleteAuthorize(); if (accessToken != null) { InMemoryTokenManager.AccessToken = accessToken; } if (auth.CachedCredentialsAvailable) { auth.SignOn(); } else { return auth.BeginAuthorize(); } twitterCtx = new TwitterContext(auth); var friendTweets = (from tweet in twitterCtx.Status where tweet.Type == StatusType.Friends select new TweetViewModel { ImageUrl = tweet.User.ProfileImageUrl, ScreenName = tweet.User.Identifier.ScreenName, Tweet = tweet.Text }) .ToList(); var friendNames = (from tweet in friendTweets select new SelectListItem { Text = tweet.ScreenName, Value = tweet.ScreenName }) .Distinct() .ToList(); var twendsVM = new TwitterFriendsViewModel { Tweets = friendTweets, FriendNames = friendNames }; return View(twendsVM); } public ActionResult About() { return View(); } } } The important part of the listing above are the LINQ to Twitter queries for friendTweets and friendNames. Both of these results are used in the subsequent population of the twendsVM instance that is passed to the view. Let’s dissect these two statements for clarification and focus on what is happening with Distinct. The query for friendTweets gets a list of the 20 most recent tweets (as specified by the Twitter API for friend queries) and performs a projection into the custom TweetViewModel class, repeated below for your convenience: var friendTweets = (from tweet in twitterCtx.Status where tweet.Type == StatusType.Friends select new TweetViewModel { ImageUrl = tweet.User.ProfileImageUrl, ScreenName = tweet.User.Identifier.ScreenName, Tweet = tweet.Text }) .ToList(); The LINQ to Twitter query above simplifies what we need to work with in the View and the reduces the amount of information we have to look at in subsequent queries. Given the friendTweets above, the next query performs another projection into an MVC SelectListItem, which is required for binding to the DropDownList.  This brings us to the focus of this blog post, writing a correct query that uses the Distinct operator. The query below uses LINQ to Objects, querying the friendTweets collection to get friendNames: var friendNames = (from tweet in friendTweets select new SelectListItem { Text = tweet.ScreenName, Value = tweet.ScreenName }) .Distinct() .ToList(); The above implementation of Distinct seems normal, but it is deceptively incorrect. After running the query above, by executing the application, you’ll notice that the drop-down list contains many duplicates.  This will send you back to the code scratching your head, but there’s a reason why this happens. To understand the problem, we must examine how Distinct works in LINQ to Objects. Distinct has two overloads: one without parameters, as shown above, and another that takes a parameter of type IEqualityComparer<T>.  In the case above, no parameters, Distinct will call EqualityComparer<T>.Default behind the scenes to make comparisons as it iterates through the list. You don’t have problems with the built-in types, such as string, int, DateTime, etc, because they all implement IEquatable<T>. However, many .NET Framework classes, such as SelectListItem, don’t implement IEquatable<T>. So, what happens is that EqualityComparer<T>.Default results in a call to Object.Equals, which performs reference equality on reference type objects.  You don’t have this problem with value types because the default implementation of Object.Equals is bitwise equality. However, most of your projections that use Distinct are on classes, just like the SelectListItem used in this demo application. So, the reason why Distinct didn’t produce the results we wanted was because we used a type that doesn’t define its own equality and Distinct used the default reference equality. This resulted in all objects being included in the results because they are all separate instances in memory with unique references. As you might have guessed, the solution to the problem is to use the second overload of Distinct that accepts an IEqualityComparer<T> instance. If you were projecting into your own custom type, you could make that type implement IEqualityComparer<T>, but SelectListItem belongs to the .NET Framework Class Library.  Therefore, the solution is to create a custom type to implement IEqualityComparer<T>, as in the SelectListItemComparer class, shown below: using System.Collections.Generic; using System.Web.Mvc; namespace DistinctSelectList.Models { public class SelectListItemComparer : EqualityComparer { public override bool Equals(SelectListItem x, SelectListItem y) { return x.Value.Equals(y.Value); } public override int GetHashCode(SelectListItem obj) { return obj.Value.GetHashCode(); } } } The SelectListItemComparer class above doesn’t implement IEqualityComparer<SelectListItem>, but rather derives from EqualityComparer<SelectListItem>. Microsoft recommends this approach for consistency with the behavior of generic collection classes. However, if your custom type already derives from a base class, go ahead and implement IEqualityComparer<T>, which will still work. EqualityComparer is an abstract class, that implements IEqualityComparer<T> with Equals and GetHashCode abstract methods. For the purposes of this application, the SelectListItem.Value property is sufficient to determine if two items are equal.   Since SelectListItem.Value is type string, the code delegates equality to the string class. The code also delegates the GetHashCode operation to the string class.You might have other criteria in your own object and would need to define what it means for your object to be equal. Now that we have an IEqualityComparer<SelectListItem>, let’s fix the problem. The code below modifies the query where we want distinct values: var friendNames = (from tweet in friendTweets select new SelectListItem { Text = tweet.ScreenName, Value = tweet.ScreenName }) .Distinct(new SelectListItemComparer()) .ToList(); Notice how the code above passes a new instance of SelectListItemComparer as the parameter to the Distinct operator. Now, when you run the application, the drop-down list will behave as you expect, showing only a unique set of names. In addition to Distinct, other LINQ Standard Query Operators have overloads that accept IEqualityComparer<T>’s, You can use the same techniques as shown here, with SelectListItemComparer, with those other operators as well. Now you know how to resolve problems with getting Distinct to work properly and also have a way to fix problems with other operators that require equality comparisons. @JoeMayo

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  • VS 2010 SP1 and SQL CE

    - by ScottGu
    Last month we released the Beta of VS 2010 Service Pack 1 (SP1).  You can learn more about the VS 2010 SP1 Beta from Jason Zander’s two blog posts about it, and from Scott Hanselman’s blog post that covers some of the new capabilities enabled with it.   You can download and install the VS 2010 SP1 Beta here. Last week I blogged about the new Visual Studio support for IIS Express that we are adding with VS 2010 SP1. In today’s post I’m going to talk about the new VS 2010 SP1 tooling support for SQL CE, and walkthrough some of the cool scenarios it enables.  SQL CE – What is it and why should you care? SQL CE is a free, embedded, database engine that enables easy database storage. No Database Installation Required SQL CE does not require you to run a setup or install a database server in order to use it.  You can simply copy the SQL CE binaries into the \bin directory of your ASP.NET application, and then your web application can use it as a database engine.  No setup or extra security permissions are required for it to run. You do not need to have an administrator account on the machine. Just copy your web application onto any server and it will work. This is true even of medium-trust applications running in a web hosting environment. SQL CE runs in-memory within your ASP.NET application and will start-up when you first access a SQL CE database, and will automatically shutdown when your application is unloaded.  SQL CE databases are stored as files that live within the \App_Data folder of your ASP.NET Applications. Works with Existing Data APIs SQL CE 4 works with existing .NET-based data APIs, and supports a SQL Server compatible query syntax.  This means you can use existing data APIs like ADO.NET, as well as use higher-level ORMs like Entity Framework and NHibernate with SQL CE.  This enables you to use the same data programming skills and data APIs you know today. Supports Development, Testing and Production Scenarios SQL CE can be used for development scenarios, testing scenarios, and light production usage scenarios.  With the SQL CE 4 release we’ve done the engineering work to ensure that SQL CE won’t crash or deadlock when used in a multi-threaded server scenario (like ASP.NET).  This is a big change from previous releases of SQL CE – which were designed for client-only scenarios and which explicitly blocked running in web-server environments.  Starting with SQL CE 4 you can use it in a web-server as well. There are no license restrictions with SQL CE.  It is also totally free. Easy Migration to SQL Server SQL CE is an embedded database – which makes it ideal for development, testing, and light-usage scenarios.  For high-volume sites and applications you’ll probably want to migrate your database to use SQL Server Express (which is free), SQL Server or SQL Azure.  These servers enable much better scalability, more development features (including features like Stored Procedures – which aren’t supported with SQL CE), as well as more advanced data management capabilities. We’ll ship migration tools that enable you to optionally take SQL CE databases and easily upgrade them to use SQL Server Express, SQL Server, or SQL Azure.  You will not need to change your code when upgrading a SQL CE database to SQL Server or SQL Azure.  Our goal is to enable you to be able to simply change the database connection string in your web.config file and have your application just work. New Tooling Support for SQL CE in VS 2010 SP1 VS 2010 SP1 includes much improved tooling support for SQL CE, and adds support for using SQL CE within ASP.NET projects for the first time.  With VS 2010 SP1 you can now: Create new SQL CE Databases Edit and Modify SQL CE Database Schema and Indexes Populate SQL CE Databases within Data Use the Entity Framework (EF) designer to create model layers against SQL CE databases Use EF Code First to define model layers in code, then create a SQL CE database from them, and optionally edit the DB with VS Deploy SQL CE databases to remote servers using Web Deploy and optionally convert them to full SQL Server databases You can take advantage of all of the above features from within both ASP.NET Web Forms and ASP.NET MVC based projects. Download You can enable SQL CE tooling support within VS 2010 by first installing VS 2010 SP1 (beta). Once SP1 is installed, you’ll also then need to install the SQL CE Tools for Visual Studio download.  This is a separate download that enables the SQL CE tooling support for VS 2010 SP1. Walkthrough of Two Scenarios In this blog post I’m going to walkthrough how you can take advantage of SQL CE and VS 2010 SP1 using both an ASP.NET Web Forms and an ASP.NET MVC based application. Specifically, we’ll walkthrough: How to create a SQL CE database using VS 2010 SP1, then use the EF4 visual designers in Visual Studio to construct a model layer from it, and then display and edit the data using an ASP.NET GridView control. How to use an EF Code First approach to define a model layer using POCO classes and then have EF Code-First “auto-create” a SQL CE database for us based on our model classes.  We’ll then look at how we can use the new VS 2010 SP1 support for SQL CE to inspect the database that was created, populate it with data, and later make schema changes to it.  We’ll do all this within the context of an ASP.NET MVC based application. You can follow the two walkthroughs below on your own machine by installing VS 2010 SP1 (beta) and then installing the SQL CE Tools for Visual Studio download (which is a separate download that enables SQL CE tooling support for VS 2010 SP1). Walkthrough 1: Create a SQL CE Database, Create EF Model Classes, Edit the Data with a GridView This first walkthrough will demonstrate how to create and define a SQL CE database within an ASP.NET Web Form application.  We’ll then build an EF model layer for it and use that model layer to enable data editing scenarios with an <asp:GridView> control. Step 1: Create a new ASP.NET Web Forms Project We’ll begin by using the File->New Project menu command within Visual Studio to create a new ASP.NET Web Forms project.  We’ll use the “ASP.NET Web Application” project template option so that it has a default UI skin implemented: Step 2: Create a SQL CE Database Right click on the “App_Data” folder within the created project and choose the “Add->New Item” menu command: This will bring up the “Add Item” dialog box.  Select the “SQL Server Compact 4.0 Local Database” item (new in VS 2010 SP1) and name the database file to create “Store.sdf”: Note that SQL CE database files have a .sdf filename extension. Place them within the /App_Data folder of your ASP.NET application to enable easy deployment. When we clicked the “Add” button above a Store.sdf file was added to our project: Step 3: Adding a “Products” Table Double-clicking the “Store.sdf” database file will open it up within the Server Explorer tab.  Since it is a new database there are no tables within it: Right click on the “Tables” icon and choose the “Create Table” menu command to create a new database table.  We’ll name the new table “Products” and add 4 columns to it.  We’ll mark the first column as a primary key (and make it an identify column so that its value will automatically increment with each new row): When we click “ok” our new Products table will be created in the SQL CE database. Step 4: Populate with Data Once our Products table is created it will show up within the Server Explorer.  We can right-click it and choose the “Show Table Data” menu command to edit its data: Let’s add a few sample rows of data to it: Step 5: Create an EF Model Layer We have a SQL CE database with some data in it – let’s now create an EF Model Layer that will provide a way for us to easily query and update data within it. Let’s right-click on our project and choose the “Add->New Item” menu command.  This will bring up the “Add New Item” dialog – select the “ADO.NET Entity Data Model” item within it and name it “Store.edmx” This will add a new Store.edmx item to our solution explorer and launch a wizard that allows us to quickly create an EF model: Select the “Generate From Database” option above and click next.  Choose to use the Store.sdf SQL CE database we just created and then click next again.  The wizard will then ask you what database objects you want to import into your model.  Let’s choose to import the “Products” table we created earlier: When we click the “Finish” button Visual Studio will open up the EF designer.  It will have a Product entity already on it that maps to the “Products” table within our SQL CE database: The VS 2010 SP1 EF designer works exactly the same with SQL CE as it does already with SQL Server and SQL Express.  The Product entity above will be persisted as a class (called “Product”) that we can programmatically work against within our ASP.NET application. Step 6: Compile the Project Before using your model layer you’ll need to build your project.  Do a Ctrl+Shift+B to compile the project, or use the Build->Build Solution menu command. Step 7: Create a Page that Uses our EF Model Layer Let’s now create a simple ASP.NET Web Form that contains a GridView control that we can use to display and edit the our Products data (via the EF Model Layer we just created). Right-click on the project and choose the Add->New Item command.  Select the “Web Form from Master Page” item template, and name the page you create “Products.aspx”.  Base the master page on the “Site.Master” template that is in the root of the project. Add an <h2>Products</h2> heading the new Page, and add an <asp:gridview> control within it: Then click the “Design” tab to switch into design-view. Select the GridView control, and then click the top-right corner to display the GridView’s “Smart Tasks” UI: Choose the “New data source…” drop down option above.  This will bring up the below dialog which allows you to pick your Data Source type: Select the “Entity” data source option – which will allow us to easily connect our GridView to the EF model layer we created earlier.  This will bring up another dialog that allows us to pick our model layer: Select the “StoreEntities” option in the dropdown – which is the EF model layer we created earlier.  Then click next – which will allow us to pick which entity within it we want to bind to: Select the “Products” entity in the above dialog – which indicates that we want to bind against the “Product” entity class we defined earlier.  Then click the “Enable automatic updates” checkbox to ensure that we can both query and update Products.  When you click “Finish” VS will wire-up an <asp:EntityDataSource> to your <asp:GridView> control: The last two steps we’ll do will be to click the “Enable Editing” checkbox on the Grid (which will cause the Grid to display an “Edit” link on each row) and (optionally) use the Auto Format dialog to pick a UI template for the Grid. Step 8: Run the Application Let’s now run our application and browse to the /Products.aspx page that contains our GridView.  When we do so we’ll see a Grid UI of the Products within our SQL CE database. Clicking the “Edit” link for any of the rows will allow us to edit their values: When we click “Update” the GridView will post back the values, persist them through our EF Model Layer, and ultimately save them within our SQL CE database. Learn More about using EF with ASP.NET Web Forms Read this tutorial series on the http://asp.net site to learn more about how to use EF with ASP.NET Web Forms.  The tutorial series uses SQL Express as the database – but the nice thing is that all of the same steps/concepts can also now also be done with SQL CE.   Walkthrough 2: Using EF Code-First with SQL CE and ASP.NET MVC 3 We used a database-first approach with the sample above – where we first created the database, and then used the EF designer to create model classes from the database.  In addition to supporting a designer-based development workflow, EF also enables a more code-centric option which we call “code first development”.  Code-First Development enables a pretty sweet development workflow.  It enables you to: Define your model objects by simply writing “plain old classes” with no base classes or visual designer required Use a “convention over configuration” approach that enables database persistence without explicitly configuring anything Optionally override the convention-based persistence and use a fluent code API to fully customize the persistence mapping Optionally auto-create a database based on the model classes you define – allowing you to start from code first I’ve done several blog posts about EF Code First in the past – I really think it is great.  The good news is that it also works very well with SQL CE. The combination of SQL CE, EF Code First, and the new VS tooling support for SQL CE, enables a pretty nice workflow.  Below is a simple example of how you can use them to build a simple ASP.NET MVC 3 application. Step 1: Create a new ASP.NET MVC 3 Project We’ll begin by using the File->New Project menu command within Visual Studio to create a new ASP.NET MVC 3 project.  We’ll use the “Internet Project” template so that it has a default UI skin implemented: Step 2: Use NuGet to Install EFCodeFirst Next we’ll use the NuGet package manager (automatically installed by ASP.NET MVC 3) to add the EFCodeFirst library to our project.  We’ll use the Package Manager command shell to do this.  Bring up the package manager console within Visual Studio by selecting the View->Other Windows->Package Manager Console menu command.  Then type: install-package EFCodeFirst within the package manager console to download the EFCodeFirst library and have it be added to our project: When we enter the above command, the EFCodeFirst library will be downloaded and added to our application: Step 3: Build Some Model Classes Using a “code first” based development workflow, we will create our model classes first (even before we have a database).  We create these model classes by writing code. For this sample, we will right click on the “Models” folder of our project and add the below three classes to our project: The “Dinner” and “RSVP” model classes above are “plain old CLR objects” (aka POCO).  They do not need to derive from any base classes or implement any interfaces, and the properties they expose are standard .NET data-types.  No data persistence attributes or data code has been added to them.   The “NerdDinners” class derives from the DbContext class (which is supplied by EFCodeFirst) and handles the retrieval/persistence of our Dinner and RSVP instances from a database. Step 4: Listing Dinners We’ve written all of the code necessary to implement our model layer for this simple project.  Let’s now expose and implement the URL: /Dinners/Upcoming within our project.  We’ll use it to list upcoming dinners that happen in the future. We’ll do this by right-clicking on our “Controllers” folder and select the “Add->Controller” menu command.  We’ll name the Controller we want to create “DinnersController”.  We’ll then implement an “Upcoming” action method within it that lists upcoming dinners using our model layer above.  We will use a LINQ query to retrieve the data and pass it to a View to render with the code below: We’ll then right-click within our Upcoming method and choose the “Add-View” menu command to create an “Upcoming” view template that displays our dinners.  We’ll use the “empty” template option within the “Add View” dialog and write the below view template using Razor: Step 4: Configure our Project to use a SQL CE Database We have finished writing all of our code – our last step will be to configure a database connection-string to use. We will point our NerdDinners model class to a SQL CE database by adding the below <connectionString> to the web.config file at the top of our project: EF Code First uses a default convention where context classes will look for a connection-string that matches the DbContext class name.  Because we created a “NerdDinners” class earlier, we’ve also named our connectionstring “NerdDinners”.  Above we are configuring our connection-string to use SQL CE as the database, and telling it that our SQL CE database file will live within the \App_Data directory of our ASP.NET project. Step 5: Running our Application Now that we’ve built our application, let’s run it! We’ll browse to the /Dinners/Upcoming URL – doing so will display an empty list of upcoming dinners: You might ask – but where did it query to get the dinners from? We didn’t explicitly create a database?!? One of the cool features that EF Code-First supports is the ability to automatically create a database (based on the schema of our model classes) when the database we point it at doesn’t exist.  Above we configured  EF Code-First to point at a SQL CE database in the \App_Data\ directory of our project.  When we ran our application, EF Code-First saw that the SQL CE database didn’t exist and automatically created it for us. Step 6: Using VS 2010 SP1 to Explore our newly created SQL CE Database Click the “Show all Files” icon within the Solution Explorer and you’ll see the “NerdDinners.sdf” SQL CE database file that was automatically created for us by EF code-first within the \App_Data\ folder: We can optionally right-click on the file and “Include in Project" to add it to our solution: We can also double-click the file (regardless of whether it is added to the project) and VS 2010 SP1 will open it as a database we can edit within the “Server Explorer” tab of the IDE. Below is the view we get when we double-click our NerdDinners.sdf SQL CE file.  We can drill in to see the schema of the Dinners and RSVPs tables in the tree explorer.  Notice how two tables - Dinners and RSVPs – were automatically created for us within our SQL CE database.  This was done by EF Code First when we accessed the NerdDinners class by running our application above: We can right-click on a Table and use the “Show Table Data” command to enter some upcoming dinners in our database: We’ll use the built-in editor that VS 2010 SP1 supports to populate our table data below: And now when we hit “refresh” on the /Dinners/Upcoming URL within our browser we’ll see some upcoming dinners show up: Step 7: Changing our Model and Database Schema Let’s now modify the schema of our model layer and database, and walkthrough one way that the new VS 2010 SP1 Tooling support for SQL CE can make this easier.  With EF Code-First you typically start making database changes by modifying the model classes.  For example, let’s add an additional string property called “UrlLink” to our “Dinner” class.  We’ll use this to point to a link for more information about the event: Now when we re-run our project, and visit the /Dinners/Upcoming URL we’ll see an error thrown: We are seeing this error because EF Code-First automatically created our database, and by default when it does this it adds a table that helps tracks whether the schema of our database is in sync with our model classes.  EF Code-First helpfully throws an error when they become out of sync – making it easier to track down issues at development time that you might otherwise only find (via obscure errors) at runtime.  Note that if you do not want this feature you can turn it off by changing the default conventions of your DbContext class (in this case our NerdDinners class) to not track the schema version. Our model classes and database schema are out of sync in the above example – so how do we fix this?  There are two approaches you can use today: Delete the database and have EF Code First automatically re-create the database based on the new model class schema (losing the data within the existing DB) Modify the schema of the existing database to make it in sync with the model classes (keeping/migrating the data within the existing DB) There are a couple of ways you can do the second approach above.  Below I’m going to show how you can take advantage of the new VS 2010 SP1 Tooling support for SQL CE to use a database schema tool to modify our database structure.  We are also going to be supporting a “migrations” feature with EF in the future that will allow you to automate/script database schema migrations programmatically. Step 8: Modify our SQL CE Database Schema using VS 2010 SP1 The new SQL CE Tooling support within VS 2010 SP1 makes it easy to modify the schema of our existing SQL CE database.  To do this we’ll right-click on our “Dinners” table and choose the “Edit Table Schema” command: This will bring up the below “Edit Table” dialog.  We can rename, change or delete any of the existing columns in our table, or click at the bottom of the column listing and type to add a new column.  Below I’ve added a new “UrlLink” column of type “nvarchar” (since our property is a string): When we click ok our database will be updated to have the new column and our schema will now match our model classes. Because we are manually modifying our database schema, there is one additional step we need to take to let EF Code-First know that the database schema is in sync with our model classes.  As i mentioned earlier, when a database is automatically created by EF Code-First it adds a “EdmMetadata” table to the database to track schema versions (and hash our model classes against them to detect mismatches between our model classes and the database schema): Since we are manually updating and maintaining our database schema, we don’t need this table – and can just delete it: This will leave us with just the two tables that correspond to our model classes: And now when we re-run our /Dinners/Upcoming URL it will display the dinners correctly: One last touch we could do would be to update our view to check for the new UrlLink property and render a <a> link to it if an event has one: And now when we refresh our /Dinners/Upcoming we will see hyperlinks for the events that have a UrlLink stored in the database: Summary SQL CE provides a free, embedded, database engine that you can use to easily enable database storage.  With SQL CE 4 you can now take advantage of it within ASP.NET projects and applications (both Web Forms and MVC). VS 2010 SP1 provides tooling support that enables you to easily create, edit and modify SQL CE databases – as well as use the standard EF designer against them.  This allows you to re-use your existing skills and data knowledge while taking advantage of an embedded database option.  This is useful both for small applications (where you don’t need the scalability of a full SQL Server), as well as for development and testing scenarios – where you want to be able to rapidly develop/test your application without having a full database instance.  SQL CE makes it easy to later migrate your data to a full SQL Server or SQL Azure instance if you want to – without having to change any code in your application.  All we would need to change in the above two scenarios is the <connectionString> value within the web.config file in order to have our code run against a full SQL Server.  This provides the flexibility to scale up your application starting from a small embedded database solution as needed. Hope this helps, Scott P.S. In addition to blogging, I am also now using Twitter for quick updates and to share links. Follow me at: twitter.com/scottgu

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  • Top 10 posts of 2010

    - by nmarun
    I quote one of my professors when I say: “We Share – We Improve”. It is through blogging that I’ve learned quite a bit. The ‘R&D’ done to learn and perfect a technology and the comments by other experts adds towards skill-set building. Below are some of the articles that I’m glad I blogged about. ASP.NET MVC 2 Model Binding for a Collection MVC 3 - first look To ref or not to ref Xap Reflector – Silverlight 4 Beware of const members LINQ to JS COM Automation with OpenOffice – Silverlight 4 VS 2010 Productivity Power Tools Using Unity Application Block – from basics to generics ASP.NET MVC Model Binding Wishing you all a happy 2011 and keep/start blogging!

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  • What php programmer should know?

    - by emchinee
    I've dig the database here and didn't found any answer for my question. What is a standard for a php programmer to know? I mean, literally, what group of language functions, mechanisms, variables should person know to consider oneself a (good) php programmer? (I know 'being good' is beyond language syntax, still I'm considering syntax of plain php only) To give an example what I mean: functions to control http sessions, cookies functions to control connection with databases functions to control file handling functions to control xml etc.. I omit phrases like 'security' or 'patterns' or 'framework' intentionally as it applies to every programming language. Hope I made myself clear, any input appreciated :) Note: Michael J.V. is right claiming that databases are independent from language, so to put my question more precisely and emphasise differences: Practises or security, are some ideas to implement (there is no 'Pattern' object with 'Decorator()' method, is there?) while using databases means knowing a mysqli and a set of its methods.

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  • Did You Know: What do you know that isn't so?

    - by Kalen Delaney
    You know what they say… it's not what you don't know that will hurt you, it's what you know that isn't so! In other words, your misconceptions. Or, as Paul Nielson calls them in his SQL Server Bible … MYTHconceptions. Some misconceptions come from misunderstanding of complex information, or from misinterpreting your own results, and assuming we can generalize behavior from one particular situation. Since I teach advanced classes to students with lots of SQL Server experience, I actually see a lot...(read more)

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  • Disable outbound links without letting others know that

    - by tadoman
    Is there a way I can tell google not to follow external links ( pointing to other sites) without letting other know. I know you can disable outbound links by putting rel=nofollow or something in robots.txt. But that's something others can see as well. I'm just wondering if there's a way to tell google not to follow those links without letting others know that... like a setting in webmaster tools or something similar ( there's definetly one way. I could set an exception in my conf file for my server to check the user agent to be "googlebot" and then serve a different version of robots.txt. So that when a different user would check that link it would return a different robots.txt thant the one served to googlebot. However I'm not too sure google would be too happy about this) Thank you

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  • Easier ASP.NET MVC Routing

    - by Steve Wilkes
    I've recently refactored the way Routes are declared in an ASP.NET MVC application I'm working on, and I wanted to share part of the system I came up with; a really easy way to declare and keep track of ASP.NET MVC Routes, which then allows you to find the name of the Route which has been selected for the current request. Traditional MVC Route Declaration Traditionally, ASP.NET MVC Routes are added to the application's RouteCollection using overloads of the RouteCollection.MapRoute() method; for example, this is the standard way the default Route which matches /controller/action URLs is created: routes.MapRoute(     "Default",     "{controller}/{action}/{id}",     new { controller = "Home", action = "Index", id = UrlParameter.Optional }); The first argument declares that this Route is to be named 'Default', the second specifies the Route's URL pattern, and the third contains the URL pattern segments' default values. To then write a link to a URL which matches the default Route in a View, you can use the HtmlHelper.RouteLink() method, like this: @ this.Html.RouteLink("Default", new { controller = "Orders", action = "Index" }) ...that substitutes 'Orders' into the {controller} segment of the default Route's URL pattern, and 'Index' into the {action} segment. The {Id} segment was declared optional and isn't specified here. That's about the most basic thing you can do with MVC routing, and I already have reservations: I've duplicated the magic string "Default" between the Route declaration and the use of RouteLink(). This isn't likely to cause a problem for the default Route, but once you get to dozens of Routes the duplication is a pain. There's no easy way to get from the RouteLink() method call to the declaration of the Route itself, so getting the names of the Route's URL parameters correct requires some effort. The call to MapRoute() is quite verbose; with dozens of Routes this gets pretty ugly. If at some point during a request I want to find out the name of the Route has been matched.... and I can't. To get around these issues, I wanted to achieve the following: Make declaring a Route very easy, using as little code as possible. Introduce a direct link between where a Route is declared, where the Route is defined and where the Route's name is used, so I can use Visual Studio's Go To Definition to get from a call to RouteLink() to the declaration of the Route I'm using, making it easier to make sure I use the correct URL parameters. Create a way to access the currently-selected Route's name during the execution of a request. My first step was to come up with a quick and easy syntax for declaring Routes. 1 . An Easy Route Declaration Syntax I figured the easiest way of declaring a route was to put all the information in a single string with a special syntax. For example, the default MVC route would be declared like this: "{controller:Home}/{action:Index}/{Id}*" This contains the same information as the regular way of defining a Route, but is far more compact: The default values for each URL segment are specified in a colon-separated section after the segment name The {Id} segment is declared as optional simply by placing a * after it That's the default route - a pretty simple example - so how about this? routes.MapRoute(     "CustomerOrderList",     "Orders/{customerRef}/{pageNo}",     new { controller = "Orders", action = "List", pageNo = UrlParameter.Optional },     new { customerRef = "^[a-zA-Z0-9]+$", pageNo = "^[0-9]+$" }); This maps to the List action on the Orders controller URLs which: Start with the string Orders/ Then have a {customerRef} set of characters and numbers Then optionally a numeric {pageNo}. And again, it’s quite verbose. Here's my alternative: "Orders/{customerRef:^[a-zA-Z0-9]+$}/{pageNo:^[0-9]+$}*->Orders/List" Quite a bit more brief, and again, containing the same information as the regular way of declaring Routes: Regular expression constraints are declared after the colon separator, the same as default values The target controller and action are specified after the -> The {pageNo} is defined as optional by placing a * after it With an appropriate parser that gave me a nice, compact and clear way to declare routes. Next I wanted to have a single place where Routes were declared and accessed. 2. A Central Place to Declare and Access Routes I wanted all my Routes declared in one, dedicated place, which I would also use for Route names when calling RouteLink(). With this in mind I made a single class named Routes with a series of public, constant fields, each one relating to a particular Route. With this done, I figured a good place to actually declare each Route was in an attribute on the field defining the Route’s name; the attribute would parse the Route definition string and make the resulting Route object available as a property. I then made the Routes class examine its own fields during its static setup, and cache all the attribute-created Route objects in an internal Dictionary. Finally I made Routes use that cache to register the Routes when requested, and to access them later when required. So the Routes class declares its named Routes like this: public static class Routes{     [RouteDefinition("Orders/{customerName}->Orders/Index")]     public const string OrdersCustomerIndex = "OrdersCustomerIndex";     [RouteDefinition("Orders/{customerName}/{orderId:^([0-9]+)$}->Orders/Details")]     public const string OrdersDetails = "OrdersDetails";     [RouteDefinition("{controller:Home}*/{action:Index}*")]     public const string Default = "Default"; } ...which are then used like this: @ this.Html.RouteLink(Routes.Default, new { controller = "Orders", action = "Index" }) Now that using Go To Definition on the Routes.Default constant takes me to where the Route is actually defined, it's nice and easy to quickly check on the parameter names when using RouteLink(). Finally, I wanted to be able to access the name of the current Route during a request. 3. Recovering the Route Name The RouteDefinitionAttribute creates a NamedRoute class; a simple derivative of Route, but with a Name property. When the Routes class examines its fields and caches all the defined Routes, it has access to the name of the Route through the name of the field against which it is defined. It was therefore a pretty easy matter to have Routes give NamedRoute its name when it creates its cache of Routes. This means that the Route which is found in RequestContext.RouteData.Route is now a NamedRoute, and I can recover the Route's name during a request. For visibility, I made NamedRoute.ToString() return the Route name and URL pattern, like this: The screenshot is from an example project I’ve made on bitbucket; it contains all the named route classes and an MVC 3 application which demonstrates their use. I’ve found this way of defining and using Routes much tidier than the default MVC system, and you find it useful too

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