PolicyMutatedEvent 

Example 

Registration of the event listener in the extension's Services.yaml:

services:
  # Place here the default dependency injection configuration

  MyVendor\MyExtension\ContentSecurityPolicy\EventListener\MyEventListener:
    tags:
      - name: event.listener
        identifier: 'my-extension/mutate-policy'

Read how to configure dependency injection in extensions.

The corresponding event listener class:

<?php

declare(strict_types=1);

namespace MyVendor\MyExtension\ContentSecurityPolicy\EventListener;

use TYPO3\CMS\Core\Security\ContentSecurityPolicy\Directive;
use TYPO3\CMS\Core\Security\ContentSecurityPolicy\Event\PolicyMutatedEvent;
use TYPO3\CMS\Core\Security\ContentSecurityPolicy\UriValue;

final class MyEventListener
{
    public function __invoke(PolicyMutatedEvent $event): void
    {
        if ($event->scope->type->isFrontend()) {
            // In our example, only the backend policy should be adjusted
            return;
        }

        // Allow images from example.org
        $event->getCurrentPolicy()->extend(
            Directive::ImgSrc,
            new UriValue('https://example.org/'),
        );
    }
}

API 

class PolicyMutatedEvent

Fully qualified name

\TYPO3\CMS\Core\Security\ContentSecurityPolicy\Event\PolicyMutatedEvent

public readonly scope

public readonly defaultPolicy

isPropagationStopped ( )

Returns

bool

stopPropagation ( )

getCurrentPolicy ( )

Returns

TYPO3CMSCoreSecurityContentSecurityPolicyPolicy

setCurrentPolicy ( \TYPO3\CMS\Core\Security\ContentSecurityPolicy\Policy $currentPolicy)

param $currentPolicy

the currentPolicy

getMutationCollections ( )

Returns

list<MutationCollection>

setMutationCollections ( \TYPO3\CMS\Core\Security\ContentSecurityPolicy\MutationCollection ...$mutationCollections)

param $mutationCollections

the mutationCollections