(C# ASP.NET Core) SignOutAsync with Tag Helpers

How does SignOut take place?

Step 1: First create a function for Sign out

The function can be created in the login page to keep it close to the login code.

But this function will be called from another page - possibly deep inside some "Area" folder. So this function will have to be connected to the click of some anchor tag helper, which is technically a GET request. Hence the name should be prefixed with OnGet

// the name of the function is prefixed 
// with OnGet because this function will be 
// called from a click of some anchor 
// tag helper 
public async Task<IActionResult> OnGetSignOut()
{

  // code here 

  // redirection to login page 
}

Step 2: Call the SignOut function to sign the user out.

// built-in function for sign out 
// kills the login cookie 
await HttpContext.SignOutAsync(
    CookieAuthenticationDefaults.AuthenticationScheme);


// NOTE: CookieAuthenticationDefaults.AuthenticationScheme 
// is a fixed constant "Cookies". the constant MUST be 
// passed as a parameter 

Step 3: Use LocalRedirect to redirect the user to the login page or to the website home page.

The completed code is shown below.

public async Task<IActionResult> OnGetSignOut()
{

  // kills the login cookie 
  await HttpContext.SignOutAsync(
      CookieAuthenticationDefaults.AuthenticationScheme);

  // redirect to web home or login page 
  return LocalRedirect("/");

}

Video Explanation

Please watch the following youtube video:

How is Click connected?

The above function is to be called from the click of some anchor tag helper. Following is an example markup:

// it is assumed that the  
// function OnGetSignOut is written 
// in the backing class "Login.cshtml.cs" 

// this mark-up is on, say, a header strip  
// of some razor page 

<div class="navbar-nav">

    <div class="nav-item text-nowrap">

      <a  asp-page-handler="SignOut" asp-page="Login">Sign out</a>

    </div>

</div>