Asp.net-mvc – How does the Authorize tag work? – ASP.NET MVC

asp.net-membershipasp.net-mvc

How does the Authorize Tag determine if the user is authorized or not?

Like say, if a user logs in and they try to go to a view that has an Authorize tag. How does it determine if a user is authorized or not? Does it do a query to database and check?

How about if they go to a view with a role authorization? Does it query the membership role table?

I am just wondering since I have what the ASP.NET membership tables considers duplicate userNames. I use a serious of fields to determine which user is what, allowing users to have the same duplicate userName, but still be unique in my database.

This caused me to have to write custom methods for lots of .NET membership stuff since it all used "userName" to do searching instead of using the UserId.

So I am now wondering if this could be the case with the Authorize tag. Since I have no clue how it works and like if I was not using .NET membership I would not have a clue how it would determine it.

Best Answer

The Authorize tag uses all the built in membership checks from ASP.NET. It's VERY easy to role your own tag. For example:

public class MyAuthorize : AuthorizeAttribute
{
    protected override bool AuthorizeCore(HttpContextBase httpContext)
    {
        if (httpContext == null) throw new ArgumentNullException("httpContext");

        // Make sure the user is authenticated.
        if (httpContext.User.Identity.IsAuthenticated == false) return false;

        // Do you own custom stuff here
        bool allow = CheckIfAllowedToAccessStuff();

        return allow;
    }
}

You then can use the [MyAuthorize] tag which will use your custom checks.

Related Solutions

Asp.net-mvc – Compile Views in ASP.NET MVC

From the readme word doc for RC1 (not indexed by google)

ASP.NET Compiler Post-Build Step

Currently, errors within a view file are not detected until run time. To let you detect these errors at compile time, ASP.NET MVC projects now include an MvcBuildViews property, which is disabled by default. To enable this property, open the project file and set the MvcBuildViews property to true, as shown in the following example:

<Project ToolsVersion="3.5" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
  <PropertyGroup>
    <MvcBuildViews>true</MvcBuildViews>
  </PropertyGroup>

Note Enabling this feature adds some overhead to the build time.

You can update projects that were created with previous releases of MVC to include build-time validation of views by performing the following steps:

Open the project file in a text editor.
Add the following element under the top-most <PropertyGroup> element: <MvcBuildViews>true</MvcBuildViews>
At the end of the project file, uncomment the <Target Name="AfterBuild"> element and modify it to match the following:

<Target Name="AfterBuild" Condition="'$(MvcBuildViews)'=='true'">
    <AspNetCompiler VirtualPath="temp" PhysicalPath="$(ProjectDir)\..\$(ProjectName)" />
</Target>

C# – How to create a dropdownlist from an enum in ASP.NET MVC

For MVC v5.1 use Html.EnumDropDownListFor

@Html.EnumDropDownListFor(
    x => x.YourEnumField,
    "Select My Type", 
    new { @class = "form-control" })

For MVC v5 use EnumHelper

@Html.DropDownList("MyType", 
   EnumHelper.GetSelectList(typeof(MyType)) , 
   "Select My Type", 
   new { @class = "form-control" })

For MVC 5 and lower

I rolled Rune's answer into an extension method:

namespace MyApp.Common
{
    public static class MyExtensions{
        public static SelectList ToSelectList<TEnum>(this TEnum enumObj)
            where TEnum : struct, IComparable, IFormattable, IConvertible
        {
            var values = from TEnum e in Enum.GetValues(typeof(TEnum))
                select new { Id = e, Name = e.ToString() };
            return new SelectList(values, "Id", "Name", enumObj);
        }
    }
}

This allows you to write:

ViewData["taskStatus"] = task.Status.ToSelectList();

by using MyApp.Common