PowerShell to update custom Sign In Page for SharePoint web application

Set-PSDebug -Strict

Set-StrictMode -Version Latest

function Ensure-WebApplicationSignInURL

{

    [CmdletBinding()]

    param 

    (

    [Parameter(Mandatory=$true)]

    [string]$webAppURL,

    [Parameter(Mandatory=$true)]

    [string]$signInURL

    )

    $webApp = Get-SPWebApplication $webAppURL

    if(($webApp.IisSettings['Default'].ClaimsAuthenticationRedirectionUrl) -eq $Null)

    {

        Write-Host "Updating Sign-In Page URL for web application $($webAppURL)"

        Set-SPWebApplication -Identity $webapp.Name -Zone:Default -SignInRedirectURL $signInURL

        Write-Host "Sucessfully updated Sign-In Page URL for $($webAppURL)" -ForegroundColor Green

    }

    else

    {

        Write-Host "Skipped updating Sign-In page URL as it already exists" -ForegroundColor Yellow

    }

}

Ensure-WebApplicationSignInURL -webAppURL "WEBAPPURL" -signInURL "SIGNINPAGEURL"