Authorize Tag Helper


The Authorize tag helper allows you render blocks of HTML only for users who are authorized based on ASP.NET Core Authorization Roles and Policies. For example, a section of HTML might be rendered only if a user has the Admin role. Since everything is evaluated on the server, this tag helper provides an easy way to ensure that users only see the HTML sections they are supposed to see.

The Authorize tag helper works in the same way as the Authorize filter works for controllers and action Methods. The examples below show some common use cases.

Login Testing

Use this section to login using different username, roles and age to see how the Authorize Tag Helper can be used to hide sections of HTML.

Authorize

Razor Code:

<div asp-authorize class="col-md-4">
    <div class="panel panel-default">
        <div class="panel-heading">Welcome !!</div>
        <div class="panel-body">
            If you're logged in, you can see this section
        </div>
    </div>
</div>
<div asp-authorize asp-roles="Admin" class="col-md-4">
    <div class="panel panel-default">
        <div class="panel-heading">Admin Section</div>
        <div class="panel-body">
            Only admin users can see this section. Top secret admin things go here.
        </div>
    </div>
</div>
<div asp-authorize asp-policy="Seniors" class="col-md-4">
    <div class="panel panel-default">
        <div class="panel-heading">Seniors Only</div>
        <div class="panel-body">
            Only users age 65 or older can see this section. Early bird dinner coupons go here. The app has a policy named Seniors which requires a claim of type <i>Age</i> with a value greater than or equal to <i>65</i>.
        </div>
    </div>
</div>
<div asp-authorize asp-roles="Admin" asp-policy="Seniors" class="col-md-4">
    <div class="panel panel-default">
        <div class="panel-heading">Admin Seniors Only</div>
        <div class="panel-body">
            Only users who have both the Admin role AND are age 65 or older can see this section.
        </div>
    </div>
</div>

Authorize Resource

Resource based authorization allows you to evaluate policies/requirements for the current user against a particular resource. You can read more about resource authorization here.

The following examples shows the two uses for the Authorize Resource tag helper. First, we evaluate the EditDocument policy for the Edit link. Next, we evalute the Operations.Delete requirement for the Delete link.

Title Author Edit Delete
Iraqi Head Seeks Arms Jane
New Study of Obesity Looks for Larger Test Group Jim
Miners Refuse to Work after Death Jane
Threat Disrupts Plans to Meet About Threats Jim
Enraged Cow Injures Farmer with Ax Joe
Fish Need Water, Says Federal Advisory Committee Joe
Slowdown Continues to Accelerate Joe
Something Went Wrong in Jet Crash, Expert Says Jane
Something Went Wrong in Jet Crash, Expert Says Jane
Local High School Dropouts Cut in Half Jim
Enraged Cow Injures Farmer with Ax Joe
Officials Determine Crash Occured When Plane Hit the Ground Jim
School Boy Suspended for Holding Door Open for a Visitor Jim
Most Earthquake Damage is Caused by Shaking Joe
Teacher Strikes Idle Kids Jim

Razor Code:

<table class="table table-striped">
    <thead>
        <tr>
            <th>Title</th>
            <th>Author</th>
            <th>Edit</th>
            <th>Delete</th>
        </tr>
    </thead>
    <tbody>
       @foreach (Document document in ViewBag.Documents)
        {
            <tr>
            <td>@document.Title</td>
            <td>@document.Author</td>
            <td><a href="#" asp-authorize-resource="document" 
            asp-policy="EditDocument" class="glyphicon glyphicon-pencil"></a>
            </td>
            <td><a href="#" asp-authorize-resource="document"
            asp-requirement="Operations.Delete" class="glyphicon glyphicon-trash text-danger">                            
            </a></td>
            </tr>
        }
    </tbody>
</table>