Injecting into Custom Validation or Authorization Attributes in ASP.NET MVC

Dependency Injection can be done when using Custom Validation or Authorization attributes in ASP.NET MVC. This can be achieved Ninject’s Property injection.

Here is an example of property injection. For a property to be injected it must be annotated with [Inject].

public class ZipCodeAttribute : ValidationAttribute
{
    [Inject]
    public IZipCodeService ZipCodeService { get; set; }

    public override bool IsValid(object value)
    {
        if (value == null)
        {
            return true;
        }

        if ((value is string) && string.IsNullOrEmpty((string)value))
        {
            return true;
        }

        var zipCode = Convert.ToInt32(value);
        return this.ZipCodeService.IsValidZipCode(zipCode);
    }
}

More on “Injection of validators” can be read here.

How to get a list of all users when using ASP.NET Membership ?

ASP.NET Membership helps you manage user authentication for your websites. Its supports facilities to create user, assign roles, reset password and almost everything under the user management domain.

Its a common requirement to list down all the users using the ASP.NET Membership provider. Though ASP.NET Membership has a inbuilt MembershipProvider‘s MembershipUserCollection GetAllUsers(int pageIndex, int pageSize, out int totalRecords); method where you can pass pageIndex, pageSize using which paging also can be handled.

However I found an another way to get this list, without having to play with the pageIndex and pageSize options on this StackOverflow thread.

var users = Membership.GetAllUsers();

var userList = new List<MembershipUser>();
foreach (MembershipUser user in users) 
{
    userList.Add(user);
}

Injecting dependencies into WebViewPages / Razor View in ASP.NET MVC

Even before you start reading this post, I am sure many of you ll would have already had discussions on this like

“Why would you need to access services on your view?”

or

“Why would you want to inject dependencies into your view?”

and even

“Shouldn’t your View be plain and dumb and be used only to render HTML from a model?”

But anyways here is something that should help you, should you want to inject dependencies in your views.

For example’s sake let’s consider you have a ‘PermissionService’ which has a method IsModuleAllowedForUser(Guid userId, string moduleName) which decides if the module is allowed for the user and only then renders it. Now I want to access this service method from my view.

Demo.Services.Core.PermissionService.cs

namespace Demo.Service.Core
{
    public class PermissionService : IPermissionService
    {
        public bool IsModuleAllowedForUser(Guid userId, string moduleName)
        {
            // blah
        }
    }
}

Here’s a way to do it.

To start with we’ll need to create a class which will inherit from the WebViewPage class. I have injected the IPermissionService using property inject with Ninject.

Demo.Web.Core.MyInjectedWebViewPage.cs

using System.Web.Mvc;
using Ninject;

namespace Demo.Web.Core
{
    public abstract class MyInjectedWebViewPage : WebViewPage
    {
        [Inject]
        public IPermissionService PermissionManager { get; set; }
    }
}

in my NinjectWebCommon.cs class I have added bindings for the same

Bind<WebViewPage>().To<MaxInjectedWebViewPage<dynamic>>();
Bind<IPermissionService>().To<PermissionService>();    

and now in the view I can use the services like as shown below

@inherits MyInjectedWebViewPage

@if(PermissionManager.IsModuleAllowedForUser(Helper.GetUserId(), "precious"))
{
    <div>My precious div!</div>
}

Hope this helps :)

References:

  1. ASP.NET MVC 3 Service Location, Part 3: View Engines/View Pages
  2. Can you inject dependencies into a constructor of a custom WebViewPage, using an IOC container?

Using GIT with Visual Studio 2013

Git, has been around for quite some time now. All major repository hosting services like GitHub, Bitbucket and now even Codeplex recommended users to opt for GIT as a recommended/default type of source control system for your project.

I have been avoiding GIT for a very longg time, the only reason being is familiarity and love for SVN :) So when I wanted to created a new project – qask on Codeplex and found that the SVN option was no longer present on codeplex. I decided to (finally) give GIT a try…

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You might also want to read this beautiful question & answer on GIT vs SVN : Why is Git better than Subversion?

1. Changing the Source Control plugin

Once you have your project opened, go to ‘Tools > Options’, go to ‘Source Control’ sub menu and select ‘Microsoft Git Provider’ from the source control plugin dropdown and press ‘ok’.

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and that’s it.

2. Commit and Sync

Once you have configured as above, your team explorer will look something like this :

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you can see your pending changes, and commit with a message using the screen below :

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Post every commit you will be given an option to sync, you can sync every time you commit or whenever you want to.

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Hope this helps. A more detailed post on Git version control with Visual Studio 2013 is present here, a must read for any newbies to GIT.

C# ExceptBy() extension method.

The following extension method is used to compare values from two list and it returns entities from the first list which is not present in the second list based on the key that is passed to it.

public static IEnumerable<T> ExceptBy<T, TKey>(this IEnumerable<T> items, IEnumerable<T> other,  Func<T, TKey> getKey)
{
    return from item in items
           join otherItem in other on getKey(item)
           equals getKey(otherItem) into tempItems
           from temp in tempItems.DefaultIfEmpty()
           where ReferenceEquals(null, temp) || temp.Equals(default(T))
           select item;

}

Writing a Custom Html Helper for Button in ASP.NET Razor

Html Helpers are used when we want to have a custom html with/without some logic repeated across your application. Today I wanted to have all the buttons shown across the application behave in a particular way depending upon the logged in user, this can easily be done using HtmlHelper.

Code

public static class CustomHtmlHelpers
{
    public static MvcHtmlString CustomButton(this HtmlHelper htmlHelper, string innerHtml, IDictionary<string, string> htmlAttributes)
    {
        var builder = new TagBuilder("a") {InnerHtml = innerHtml};
        builder.MergeAttributes(htmlAttributes);
        return MvcHtmlString.Create(builder.ToString());
    }
}

In the IDictionary<string, string> htmlAttributes parameter you can pass all the html attributes you need your button to have, for example: class, href, or any other html attribute for that matter.

Example

@Html.CustomButton("<i class='fa fa-plus'></i>&nbsp; Create Something", new Dictionary<string, string> { { "class", "btn btn-primary" }, { "href", "#create" } })

You might wanna read another related article on Html Helpers.

How to pass values from ASP.NET MVC Razor Views to Angular Controller ?

I have been using a lot of AngularJs code on my razor views lately. On one of my page, I wanted to pass to my angular controller the model which is being passed to my razor view.

Can be done with the following code

ng-init="init(@JsonConvert.SerializeObject(Model))"

JsonConvert.SerializeObject helps you convert an object to a JSON string and you can use ng-init to pass and use this value in your controller.

How to configure the default ASP.NET Membership’s Role Manager in ASP.NET MVC 4

If you do not want to create your own custom Role Provider and use the ASP.NET Membership’s in built RoleManager. Then you should use the following setting in your web.config file.

<roleManager enabled="true" defaultProvider="SqlRoleProvider" >
  <providers>
    <add name="SqlRoleProvider"
         type="System.Web.Security.SqlRoleProvider"
         connectionStringName="AbcAspNetConnection"
         applicationName="Abc Web Application"/>
  </providers>
</roleManager>

Font awesome not working on IIS for ASP.NET MVC project

Here are things that you should be checking if your fontawesome is not working when you put your website on IIS.

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Check 1: Check if all the fonts (.otf, .woff etc) are copied to the /font-awesome-4.2.0/fonts/ folder.

Check 2: Remove the fontawesome.css from your bundle and add it directly like <link href="~/Content/font-awesome-4.2.0/css/font-awesome.css" rel='stylesheet' type='text/css' />

Setting up Staging, QA and Live web configs with Visual Studio 2013

Step 1 : Open the Configuration Manager dialog.
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Step 2 : Select “<New..”> option from the Active solution configuration dropdown.
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Step 3: Give some name to your configuration, and if you dont require an empty config file I would suggest you to copy the settings from the existing “Release” transform.
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Step 4: Right click on the web.config file and select the “Add Config Transform” option.
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Step 5: And you should see your Staging config created. You can similarly create a qa and production/live configs too.
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