Some of you will face this problem when using Bundling and Minification in ASP.NET MVC 4. This post cover about how to fix relative CSS Path in ASP.NET MVC 4.

Recently, I hit a known problem with deploying to IIS virtual directories. It’s not a problem for ASP.NET which understands virtual directories and so if you ask for “~” or “/” will return “yoursite/virtualfolder”. However, JavaScript is run under IIS, which doesn’t understand this idea so well. Do “/” in JS and you’ll get back “yoursite” NOT “yoursite/virtualfolder”.

So what’s the fix? Well, for JavaScript there are a couple of answers. So I check my javascript. Based on this answer, I came up with this:

1. Add a hidden field to a masterpage:

  @Html.Hidden("HiddenCurrentUrl",  Url.Content("~"))

2. As one of the first things you do, ensure this JS runs. All it does it take the value in the field and store it:

var baseUrl = "";
baseUrl = $("#HiddenCurrentUrl").val();

3. Use baseUrl wherever you need to call things in JavaScript:

Silverlight.createObject(
            baseUrl + "ClientBin/SilverlightBridge.xap",  // source
            ...
        );

Hmm… But you know, that is not the problem. The problem is with the CSS file

    .link-button.cancel {
        background-image: url('../Images/appbar.cancel.darkgrey.png');
    }

A similar problem occures where these URLs start with a slash(/) because IIS interprets that incorrectly. You can’t invoke ASP.NET, which does know the right root into a CSS file

After some messing around, I came to this compromise, which works well. It also exposes some of the hidden power of using Bundling:

1. For any images you reference in CSS, move them into a relative folder, such as /images near the CSS. I know, this may be an unacceptable compromise for you. But actually, it makes a lot of sense. The image is probably only used by the CSS so it makes sense to have it nearby, not in some global /images folder.  
2. In order to make this work, you need to get your CSS (which you’ve bundled up) into the same place relative to the images you’re reference, or at least, you need to cheat the browser into thinking this happening.
3. So, for instance:
   
     bundles.Add(new StyleBundle("~/Content/DataTableStyle").Include(
   
   comes out the other end as:
   

Don’t forget that all your “static” content, such as images won’t be affected by Bundling and can be referenced using the folder structure you expect, i.e. the one you’ve set up in Visual Studio.

So… when you create the Style Bundle you give it a name which reflects where you have it in your Visual Studio folder structure, then it will pop out the other end in the same place, relatively, to the image files which it’s references! And because the Bundling is happening via ASP.NET, the URL of the CSS file, and wherever it is referenced, works fine in virtual directories!

This article demonstrates how to integrate login button on the web page in order to obtain access token that we'll need for further tutorials.

Visual Studio project setup

Firstly, let's get started by opening visual studio and creating new ASP.NET Mvc 4 Web Application. Name it FacebookLoginButton and make sure .NET Framework 4 is selected. Click on OK. Another window should now pop up asking for a type of tempalte you'd like to install in your app. Select An Empty ASP.NET MVC Project.

Once you've got your project created, right click on Controllers folder and Add Controller. Make sure controller name is set to HomeController.

What we need now is a view associated with home controller index method. To add a view, open newly created HomeController and look for a line where it returns View() ActionResult. View() should be highligted in red. Right click on it and select Add View.

Make sure you compile your project before editing anything. There is some problem with VS 2010 and MVC 4 Razor engine. When you try to edit .cshtml file without rebuilding your solution first, VisualStudio will crash.

Import and configure facebook javascript framework

Time for a little bit of javascript-ing. Buuu. Right click on Scripts and create new Javascript file. Name it Facebook.js. Paste in following content:

function InitialiseFacebook(appId) { 

    window.fbAsyncInit = function () {
        FB.init({
            appId: appId,
            status: true,
            cookie: true,
            xfbml: true
        }); 

        FB.Event.subscribe('auth.login', function (response) {
            var credentials = { uid: response.authResponse.userID, accessToken: response.authResponse.accessToken };
            SubmitLogin(credentials);
        }); 

        FB.getLoginStatus(function (response) {
            if (response.status === 'connected') {
                alert("user is logged into fb");
            }
            else if (response.status === 'not_authorized') { alert("user is not authorised"); }
            else { alert("user is not conntected to facebook");  } 

        }); 

        function SubmitLogin(credentials) {
            $.ajax({
                url: "/account/facebooklogin",
                type: "POST",
                data: credentials,
                error: function () {
                    alert("error logging in to your facebook account.");
                },
                success: function () {
                    window.location.reload();
                }
            });
        } 

    }; 

    (function (d) {
        var js, id = 'facebook-jssdk', ref = d.getElementsByTagName('script')[0];
        if (d.getElementById(id)) {
            return;
        }
        js = d.createElement('script');
        js.id = id;
        js.async = true;
        js.src = "//connect.facebook.net/en_US/all.js";
        ref.parentNode.insertBefore(js, ref);
    } (document)); 

}

This javascript will ensure that we're subscribed to login event on which we'll submit fb access token to our controller and save it in session. Also, on each window load, we'll check for fb login status and alert user accordingly.

Sign up for an app

Now, go to developers.facebook.com and create a new app. Make sure all app's urls point to the actual address of the app. If you're running the app from Visual Studio, its address will be http://localhost:[PORT NUMBER].

Login model and controller

Next, we need to add account controller that will save facebook response in session. Before we add it, let's create a model for an object that we'll pass to account controller. Right click on Models folder and add FacebookLoginModel.cs (Class).

namespace FacebookLoginButton.Models
{
    public class FacebookLoginModel
    {
        public string uid { get; set; }
        public string accessToken { get; set; }
    }
}

Once we've got our model, we can add AccountController.cs.

using System.Web.Mvc;
using FacebookLoginButton.Models; 

namespace FacebookLoginButton.Controllers
{
    public class AccountController : Controller
    {
        [HttpPost]
        public JsonResult FacebookLogin(FacebookLoginModel model)
        {
            Session["uid"] = model.uid;
            Session["accessToken"] = model.accessToken; 

            return Json(new {success = true});
        } 

    }
}

Login button configuration

To enable facebook framework, make sure you've got following lines added to your Views -> Shared -> Layout.cshtml file. Following lines should be added just before body closing tag.

<div id="fb-root"></div>
    <script src="@Url.Content("~/Scripts/jquery-1.6.2.min.js")" type="text/javascript"></script>
    <script src="@Url.Content("~/Scripts/Facebook.js")"
type="text/javascript"></script>
    <script type="text/javascript">
        $(function () {
            InitialiseFacebook(@System.Configuration.ConfigurationManager.AppSettings["FacebookAppId"]);
        });
    </script>

Finally, modify Views -> Home -> Index.cshtml by pasting in following code:

@{
    ViewBag.Title = "Part 1 - Facebook Login Button";    Layout = "~/Views/Shared/_Layout.cshtml";
} 

<h2>Part 1 - Facebook Login Button</h2> 

<fb:login-button autologoutlink="true" perms="read_friendlists, create_event, email, publish_stream"></fb:login-button> 

<p>Facebook Access Token: @Session["accessToken"]</p>
<p>Facebook User Id: @Session["uid"]</p> 

<p>If you're not getting javascript prompts on each window load, make sure facebook app id in web config is correct.</p>

That's it. Feel free to download comleted solution attached to this post.

Done. Great job

ASP.NET MVC 4 Developer Preview is out and has some nifty new mobile features that will allow you to target mobile devices.

Mobile views

The new “Display Modes” feature lets an application render a specific view based on the device making the request. A desktop browser accessing a page might cause Index.cshtml to be rendered, but if the request comes from an iPad or an Andriod phone, Index.mobile.cshtml may be rendered. This convention-based approach lets you tailor your views without requiring any code changes.

The suffix “mobile” works out of the box, but you can also register your own display modes that target specific devices any particular way you wish. In the global.asax you could register something like the following:

DisplayModes.Modes.Insert(0, new DefaultDisplayMode("iPhone")
{
   ContextCondition = (context => context.Request.UserAgent.IndexOf
       ("iPhone", StringComparison.OrdinalIgnoreCase) >= 0)
});

This will register a mode specifically for iPhones, and allow you to create view pages with “iPhone” as a suffix, such as MyView.iPhone.cshtml.

See the release notes for additional details.

Programmatically detecting a mobile device

You may begin to add some mobile views to your application, only to realize that you actually need to customize more than just the way your views are rendered. Maybe you need to add or remove some of the data your page is querying or do something different altogether. I recently created a mobile version of this blog and couldn’t just use home controller action as-is. I wanted my mobile view to list a summary of all of my blog posts, rather than the full content of just the first 3 posts, which is what you see in a desktop browser.

HttpBrowserCapabilitiesBase browser = HttpContext.GetOverriddenBrowser();

//Some of the many properties, with values as seen from a Windows 7 Phone (emulator):

browser.Type; //IEMobile9
browser.Id; //iemobile
browser.MajorVersion; //9
browser.IsMobileDevice; //true
browser.InputType; //virtualKeyboard
browser.Crawler; //false

Simply call HttpContext.GetOverridenBrowser() to get access to the browser capabilities and you can determine whether it’s mobile, and act accordingly.  This method is an extension method in the System.Web.WebPages assembly, so don’t forget to add a using statement for this namespace!

Overriding the browser type

Detecting a mobile device like this isn’t new, of course. The first version of ASP.NET MVC allowed you to inspect the attributes of the requesting user-agent and chose the proper view to render. The downside of this is that there was no out-of-the-box way for a user to override this. Ever visit a site with your mobile phone and be presented with a stripped down view when you desperately wanted to see the full desktop-browser version, but couldn’t?

MVC 4 has this capability out-of-the-box with the SetOverriddenBrowser() extension method. You can call this and specify a browser type override. This is what the view switcher does in the jQuery.Mobile.MVC sample NuGet package, letting a user select whether they wish to be handled as a desktop or mobile device:

public RedirectResult SwitchView(bool mobile, string returnUrl) {
    if (Request.Browser.IsMobileDevice == mobile)
        HttpContext.ClearOverriddenBrowser();
    else
        HttpContext.SetOverriddenBrowser(mobile ? BrowserOverride.Mobile : BrowserOverride.Desktop);

    return Redirect(returnUrl);
}

The cool stuff comes from HTML5 and jQuery

ASP.NET MVC 4’s mobile features aren’t all that exciting to tell you the truth. The only new features so far are just some helpers and tooling around a technique that’s been around forever. That said, it’s a great addition to the framework.

What's really exciting is the things jQuery Mobile and HTML5 bring to the table, allowing you easily build slick UIs that will look great on a phone or tablet and rival a native application. For more on that, definitely check out the tutorial over on the ASP.NET website that will use these new MVC 4 features and jQuery Mobile.

Some people love them, others absolutely hate them, but if you ask me one of the coolest features in ASP.Net MVC is the Data Annotations that you use to decorate your ASP.Net MVC classes for validation. But one of the coolest things that came along in .Net 4.0 was support for this across the whole framework – even outside of ASP.Net MVC!

When working on projects outside of ASP.Net MVC its still just as relevant to write validation for your classes and their respective properties before you fire actions, communicate them to another class or simply add something to a database (among the 4 million other times validation can come in handy).

Taking what we know from ASP.Net MVC, we can easily add this functionality to the public properties of any class in any project in .Net 4, be it a Console App, Web Service, SilverLight, Windows Phone 7 – you name it.

This also means that any common libraries you use between multiple projects can have simple Data Annotations added in one place and validated everywhere – keeping your validation logic all in one place.

Getting down to business

In the project that holds the data model classes you want to add validation to, add a reference to the framework namespace System.ComponentModel.DataAnnotations



Now open the class you want to add validation to.

We are going to add the following to it:

- Add a class level meta data attribute telling our validator what type of class it is
- Add your validation decorations to any properties exactly as you would in ASP.Net MVC

In my example below, I demonstrate how to do this with a class named Person. You can see I've added a MetadataTypeAttribute of type Person above the class declaration. I’ve also added a required field decoration to the public Name property of this class.

[ MetadataTypeAttribute(typeof(Person))]
class Person
{
    [Required(ErrorMessage = "You must enter a name")]
    public string Name { get; set; }
}

Now I've got to create a new class that we will use to validate our decorated attributes against objects – in this instance our Person class above, but the same code will work for any class with the correct decorations.

Create a new class in your project and call is ClassValidator.

Paste the following code into that file:

public class ClassValidator
{
    public ClassValidator(object objectToValidate)
    {
        objectBeingValidated = objectToValidate;
    }

    private static object objectBeingValidated { get; set; }

    public List<ValidationResult> ValidationErrors { get; private set; }

    public bool IsValid()
    {
        if (objectBeingValidated != null)
        {
            ValidationErrors = new List<ValidationResult>();
            var context = new ValidationContext(objectBeingValidated,
                null,
                null);

            bool isValid = Validator.TryValidateObject(objectBeingValidated,
                context,
                ValidationErrors);

            if (!isValid)
            {
                return false;
            }
            return true;
        }
        return false;
    }
}

And we are done - That is all we need!

Using the Code

To use the above example, all you need to do, is create an instance of our ClassValidator and pass in the object we want to validate at initialisation.

We can then call the IsValid() method against it to find out if our class validates and a list of any validation errors will then be available in the public ValidationErrors property of our ClassValidator.

My example below demonstrates this usage in a console application that does the following:

- Creates an instance of the example Person object
- Doesn’t set any properties of this Person object (so our Name property will be Null - and therefore invalid)
- Creates a ClassValidator and passes in my newly created Person, and then calls IsValid against it.
- Prints all the errors found to the console.

Person p = new Person();

Console.WriteLine("Attempting to validate the person object");

ClassValidator validator = new ClassValidator(p);

Console.WriteLine("Is object valid of not?: {0}",validator.IsValid());

foreach (var error in validator.ValidationErrors)
{
    Console.WriteLine("Error in Person object: {0}", error.ErrorMessage);
}

This blog post shows how to validate models containing complex types such as Objects and Lists in ASP.NET MVC 3.

In a first step we modify the properties of the model ( Models/ValidationModel.cs) and add some complex types:

public class ValidUserNameAttribue : ValidationAttribute
{
  public override bool IsValid(object value)
  {
    return (value != null &amp;&amp; value.ToString() == "Bob");
  }
}

public class User
{
  [Required]
  [StringLength(8, MinimumLength = 3)]
  [ValidUserNameAttribue(ErrorMessage = "User name != 'Bob'")]
  [Display(Name = "User name")]
  public string UserName { get; set; }

  [Required]
  [StringLength(8, MinimumLength = 3)]
  [Display(Name = "Display name")]
  public string DisplayName { get; set; }
}

public class ValidationModel
{
  public User User { get; set; }

  public List Users { get; set; }
}

In a second step we modify the form ( Views\Home\Partial\_Form.cshtml) to add input element for the new model properties:

@model MVC3_Ajax_Form_jQuery_Validation.Models.ValidationModel

@DateTime.Now: Partial/_Form.cshtml rendered
< hr/>

@using (Html.BeginForm("Form", "Home"))
{
  <h1><em>User</em> object</h1>

  <p>
    @Html.LabelFor(m => m.User.UserName):
    @Html.EditorFor(m => m.User.UserName)
    @Html.ValidationMessageFor(m => m.User.UserName)
  </p>

  <p>
    @Html.LabelFor(m => m.User.DisplayName):
    @Html.EditorFor(m => m.User.DisplayName)
    @Html.ValidationMessageFor(m => m.User.DisplayName)
  </p>

  <h1>List of <em>User</em> objects</h1>

  for (var i = 0; i <= 1; i++)
  {
    <h2>User @i</h2>

    <p>
      @Html.LabelFor(m => m.Users[i].UserName):
      @Html.EditorFor(m => m.Users[i].UserName)
      @Html.ValidationMessageFor(m => m.Users[i].UserName)
    </p>

    <p>
      @Html.LabelFor(m => m.Users[i].DisplayName):
      @Html.EditorFor(m => m.Users[i].DisplayName)
      @Html.ValidationMessageFor(m => m.Users[i].DisplayName)
    </p>
  }

  <input type="submit" value="Submit" />
}

In a last step we adapt the “success-view” ( Views\Home\Partial\_Success.cshtml) that is shown after the data have been successfully validated on the server side:

@model MVC3_Ajax_Form_jQuery_Validation.Models.ValidationModel

< p><strong>Model is valid :)</strong></p>

< p>
  Model.User.Username: '@Model.User.UserName'<br />
  Model.User.DisplayName: '@Model.User.DisplayName'<br />
  Model.Users[0].Username: '@Model.Users[0].UserName'<br />
  Model.Users[0].DisplayName: '@Model.Users[0].DisplayName'<br />
  Model.Users[1].Username: '@Model.Users[1].UserName'<br />
  Model.Users[1].DisplayName: '@Model.Users[1].DisplayName'
</ p>

As you can see in the source code above, there is no magic; model binding and validation of complex objects and lists work out of the box in ASP.NET MVC 3.

In this blog post I will show how to set up custom error pages in ASP.NET MVC 3 applications to create user-friendly error messages instead of the (yellow) IIS default error pages for both “normal” (non-AJAX) requests and jQuery AJAX requests.

In this showcase we will implement custom error pages to handle the HTTP error codes 404 (“Not Found”) and 500 (“Internal server error”) which I think are the most common errors that could occur in web applications. In a first step we will set up the custom error pages to handle errors occurring in “normal” non-AJAX requests and in a second step we add a little JavaScript jQuery code that handles jQuery AJAX errors.

We start with a new (empty) ASP.NET MVC 3 project and activate custom errors in the Web.config by adding the following lines under <system.web>:

<customErrors mode="On" defaultRedirect="/Error">
  <error redirect="/Error/NotFound" statusCode="404"/>
  <error redirect="/Error/InternalServerError" statusCode="500"/>
</customErrors>

Note: You can set mode=”Off” to disable custom errors which could be helpful while developing or debugging. Setting mode=”RemoteOnly” activates custom errors only for remote clients, i.e. disables custom errors when accessing via http://localhost/[...]. In this example setting mode=”On” is fine since we want to test our custom errors. You can find more information about the <customErrors> element here.

In a next step we remove the following line in Global.asax.cs file:

filters.Add(new HandleErrorAttribute());

and add a new ErrorController (Controllers/ErrorController.cs):

public class ErrorController : Controller
{
  public ActionResult Index()
  {
    return InternalServerError();
  }

  public ActionResult NotFound()
  {
    Response.TrySkipIisCustomErrors = true;
    Response.StatusCode = (int)HttpStatusCode.NotFound;
    return View("NotFound");
  }

  public ActionResult InternalServerError()
  {
    Response.TrySkipIisCustomErrors = true;
    Response.StatusCode = (int)HttpStatusCode.InternalServerError;
    return View("InternalServerError");
  }
}

In a last step we add the ErrorController‘s views (Views/Error/NotFound.cshtml and Views/Error/InternalServerError.cshtml) that defines the (error) pages the end user will see in case of an error. The views include a partial view defined in Views/Shared/Error/NotFoundInfo.cshtml respectively Views/Shared/Error/InternalServerErrorInfo.cshtml that contains the concrete error messages. As we will see below using these partial views enables us to reuse the same error messages to handle AJAX errors.

Views/Error/NotFound.cshtml:

@{
  ViewBag.Title = "Not found";
}
@{
  Html.RenderPartial("Error/NotFoundInfo");
}

Views/Shared/Error/NotFoundInfo.cshtml:

The URL you have requested was not found.

Views/Error/InternalServerError.cshtml:

@{
  ViewBag.Title = "Internal server error";
}
@{
  Html.RenderPartial("Error/InternalServerErrorInfo");
}

Views/Shared/Error/InternalServerErrorInfo.cshtml:

An internal Server error occured.

To handle errors occurring in (jQuery) AJAX calls we will use jQuery UI to show a dialog containing the error messages. In order to include jQuery UI we need to add two lines to Views/Shared/_Layout.cshtml:

<link href="@Url.Content("~/Content/themes/base/jquery.ui.all.css")" rel="stylesheet" type="text/css" />

<script src="@Url.Content("~/Scripts/jquery-ui-1.8.11.min.js")" type="text/javascript"></script>

Moreover we add the following jQuery JavaScript code (defining the global AJAX error handling) and the Razor snippet (defining the dialog containers) to Views/Shared/_Layout.cshtml:

< script type="text/javascript">
  $(function () {
    // Initialize dialogs ...
    var dialogOptions = {
      autoOpen: false,
      draggable: false,
      modal: true,
      resizable: false,
      title: "Error",
      closeOnEscape: false,
      open: function () { $(".ui-dialog-titlebar-close").hide(); }, // Hide close button
      buttons: [{
        text: "Close",
        click: function () { $(this).dialog("close"); }
      }]
    };
    $("#InternalServerErrorDialog").dialog(dialogOptions);
    $("#NotFoundInfoDialog").dialog(dialogOptions);

    // Set up AJAX error handling ...
    $(document).ajaxError(function (event, jqXHR, ajaxSettings, thrownError)
{
      if (jqXHR.status == 404) {
        $("#NotFoundInfoDialog").dialog("open");
      } else if (jqXHR.status == 500) {
        $("#InternalServerErrorDialog").dialog("open");
      } else {
        alert("Something unexpected happend :( ...");
      }
    });
  });
</ script>

<div id="NotFoundInfoDialog">
  @{ Html.RenderPartial("Error/NotFoundInfo"); }
</div>
<div id="InternalServerErrorDialog">
  @{ Html.RenderPartial("Error/InternalServerErrorInfo"); }
</div>

As you can see in the Razor snippet above we reuse the error texts defined in the partial views saved in Views/Shared/Error/.


To test our custom errors we define the HomeController (Controllers/HomeController.cs) as follows:

  public class HomeController : Controller
  {
  public ActionResult Index()
  {
    return View();
  }
  public ActionResult Error500()
  {
    throw new Exception();
  }
}

and the corresponding view Views/Home/Index.cshtml:

@{
  ViewBag.Title = "ViewPage1";
}

<script type="text/javascript">
  $function () {
    $("a.ajax").click(function (event) {
      event.preventDefault();
      $.ajax({
      url: $(this).attr('href'),
    });
  });
});
</script>

<ul>
  <li>@Html.ActionLink("Error 404 (Not Found)", "Error404")</li>
  <li>@Html.ActionLink("Error 404 (Not Found) [AJAX]", "Error404", new { },
new { Class = "ajax" })</li>
  <li>@Html.ActionLink("Error 500 (Internal Server Error)", "Error500")</li>
  <li>@Html.ActionLink("Error 500 (Internal Server Error) [AJAX]", "Error500", new { }, new { Class = "ajax" })</li>
</ul>

To test the custom errors you can launch the project and click one of the four links defined in the view above. The “AJAX links” should open a dialog containing the error message and the “non-AJAX” links should redirect to a new page showing the same error message.

Summarized this blog post shows how to set up custom errors that handle errors occurring in both AJAX requests and “non-AJAX” requests. Depending on the project, one could customize the example code shown above to handle other HTTP errors as well or to show more customized error messages or dialogs.

Description

Normally in a MVC3 application we have generally 3 sections.

Model, Controller, View.

Now in a real-world project in our Application there may be many modules.

So separating each of the modules in our MVC3 application is highly recommendable.

In ASP.Net MVC3 we have features called "area" where we can separate into different modules.

For e.g. ADMIN, CUSTOMER, PRODUCT etc.

Now I will show you an example of how to create the "AREA" in MVC3.

Step 1:

Now first create an ASP.Net MVC3 application.

Step 2:

Now right-click the project and "add" a new area with the name "Admin"; that means in our project there are an "admin" module. See the following picture:

Step 3:

After adding the "admin" area you will see that a separate "Areas" folder will be created. Under this folder controller, model and views, shared folders will be generated.

Now under the "Controller" folder add a new controller named "admin controller".

Now from the "admincontroller" create a new view named "index" from the "index" method.

After that copy the "_layout.cshtml" from the main project and paste it under the "Areas" Shared folder.

Now the whole structure will look like the following once.



Step 4:

Now add a new action link for "Admin" under the _layout.cshtml" like the following picture:



<li>@Html.ActionLink("Admin", "Index", "Admin")</li>

So the admin link will be created and when we click the "admin" link it will redirect to the "admin" part of our project which is under the "Areas".

Step 5:

Now go to the "AdminAreaRegistration" file (just the following picture) and modify the existing code like below:



public override void RegisterArea(AreaRegistrationContext context)
{
context.MapRoute(
"Admin_default",
"Admin/{controller}/{action}/{id}",
new { controller = "Admin", action = "Index", id = UrlParameter.Optional }
);

I have added here only Controller Name "Admin"( controller = "Admin") extra under the new {} section.

Now run the application it will look like the following picture:



See here "Admin" link has come.

Now after clicking the admin link it will show like the following picture:



See the url routing. It calls our "Admin " Areas part.

So by this way we can group our project modules into our ASP.Net MVC3 application.

Conclusion

So in this article we have learned what is the purpose of use of "Area" features in ASP.Net MVC3 and how to implement them.

Description

Normally in a MVC3 application we have generally 3 sections.

Model, Controller, View.

Now in a real-world project in our Application there may be many modules.

So separating each of the modules in our MVC3 application is highly recommendable.

In ASP.Net MVC3 we have features called "area" where we can separate into different modules.

For e.g. ADMIN, CUSTOMER, PRODUCT etc.

Now I will show you an example of how to create the "AREA" in MVC3.

Step 1:

Now first create an ASP.Net MVC3 application.

Step 2:

Now right-click the project and "add" a new area with the name "Admin"; that means in our project there are an "admin" module. See the following picture:

Step 3:

After adding the "admin" area you will see that a separate "Areas" folder will be created. Under this folder controller, model and views, shared folders will be generated.

Now under the "Controller" folder add a new controller named "admin controller".

Now from the "admincontroller" create a new view named "index" from the "index" method.

After that copy the "_layout.cshtml" from the main project and paste it under the "Areas" Shared folder.

Now the whole structure will look like the following once.



Step 4:

Now add a new action link for "Admin" under the _layout.cshtml" like the following picture:



<li>@Html.ActionLink("Admin", "Index", "Admin")</li>

So the admin link will be created and when we click the "admin" link it will redirect to the "admin" part of our project which is under the "Areas".

Step 5:

Now go to the "AdminAreaRegistration" file (just the following picture) and modify the existing code like below:



public override void RegisterArea(AreaRegistrationContext context)
{
context.MapRoute(
"Admin_default",
"Admin/{controller}/{action}/{id}",
new { controller = "Admin", action = "Index", id = UrlParameter.Optional }
);

I have added here only Controller Name "Admin"( controller = "Admin") extra under the new {} section.

Now run the application it will look like the following picture:



See here "Admin" link has come.

Now after clicking the admin link it will show like the following picture:



See the url routing. It calls our "Admin " Areas part.

So by this way we can group our project modules into our ASP.Net MVC3 application.

Conclusion

So in this article we have learned what is the purpose of use of "Area" features in ASP.Net MVC3 and how to implement them.