..  include:: /Includes.rst.txt
..  index:: Events; ModifyRedirectUrlValidationResultEvent
..  _ModifyRedirectUrlValidationResultEvent:

======================================
ModifyRedirectUrlValidationResultEvent
======================================

..  versionadded:: 13.2
    With this event developers have the possibility to modify the validation
    results for the redirect URL, allowing redirects to URLs not matching the
    existing validation constraints.

The PSR-14 event
:php:`\TYPO3\CMS\FrontendLogin\Event\ModifyRedirectUrlValidationResultEvent`
provides developers with the possibility and flexibility to implement custom
validation for the redirect URL in the frontend login.

This may be useful, if TYPO3 frontend login
acts as an :abbr:`SSO (Single-Sign On)` system, or if users should be redirected to an external URL after
login.

Example: Validate that the redirect after frontend login goes to a trusted domain
=================================================================================

..  literalinclude:: _ModifyRedirectUrlValidationResultEvent/_ValidateRedirectUrl.php
    :language: php
    :caption: EXT:my_extension/Classes/EventListeners/ValidateRedirectUrl.php

..  include:: /_includes/EventsAttributeAdded.rst.txt

API
===

..  include:: /CodeSnippets/Events/FrontendLogin/ModifyRedirectUrlValidationResultEvent.rst.txt