AspNetCore.Docs/aspnetcore/security/authorization/views.md

title	author	description	keywords	ms.author	manager	ms.date	ms.topic	ms.assetid	ms.technology	ms.prod	uid
View Based Authorization | Microsoft Docs	rick-anderson		ASP.NET Core,	riande	wpickett	10/14/2016	article	24ce40d8-9b83-4bae-9d4c-a66350fcc8f8	aspnet	asp.net-core	security/authorization/views

View Based Authorization

Often a developer will want to show, hide or otherwise modify a UI based on the current user identity. You can access the authorization service within MVC views via dependency injection. To inject the authorization service into a Razor view use the @inject directive, for example @inject IAuthorizationService AuthorizationService (requires @using Microsoft.AspNetCore.Authorization). If you want the authorization service in every view then place the @inject directive into the _ViewImports.cshtml file in the Views directory. For more information on dependency injection into views see Dependency injection into views.

Once you have injected the authorization service you use it by calling the AuthorizeAsync method in exactly the same way as you would check during resource based authorization.

@if (await AuthorizationService.AuthorizeAsync(User, "PolicyName"))
   {
       <p>This paragraph is displayed because you fulfilled PolicyName.</p>
   }

In some cases the resource will be your view model, and you can call AuthorizeAsync in exactly the same way as you would check during resource based authorization;

@if (await AuthorizationService.AuthorizeAsync(User, Model, Operations.Edit))
   {
       <p><a class="btn btn-default" role="button"
           href="@Url.Action("Edit", "Document", new { id = Model.Id })">Edit</a></p>
   }

Here you can see the model is passed as the resource authorization should take into consideration.

[!WARNING] Do not rely on showing or hiding parts of your UI as your only authorization method. Hiding a UI element does not mean a user cannot access it. You must also authorize the user within your controller code.