Feature: #97450 - PSR-14 event for modifying version differences

Description

A new PSR-14 event \TYPO3\CMS\Workspaces\Event\ModifyVersionDifferencesEvent has been introduced which serves as a direct replacement for the now removed $GLOBALS['TYPO3_CONF_VARS']['SC_OPTIONS']['workspaces']['modifyDifferenceArray'] hook.

It can be used to modify the version differences data, used for the display in the Workspaces backend module. Those data can be accessed with the getVersionDifferences() method, and updated using the setVersionDifferences(array $versionDifferences) method.

The version differences array contains the differences of each field, with the following keys:

field: The corresponding field name,
label: The corresponding fields' label,
content: The field values difference

Furthermore does the event provide the following methods

getLiveRecordData(): Returns the records live data (used to create the version difference)
getParameters(): Returns meta information like current stage and current workspace

Note

The removed hook allowed to update the live record data. This however had no effect since those data are not further used by TYPO3. Therefore, the new event does no longer provide a setter for the live record data.

Note

The removed hook contained an instance of DiffUtility, which can be used to generate the differences string. Since PSR-14 events are usually pure data objects, without dependencies to any service, the new PSR-14 event does no longer provide an instance of DiffUtility. Listeners have to inject the service on their own - if needed.

Example

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

MyVendor\MyPackage\Workspaces\MyEventListener:
  tags:
    - name: event.listener
      identifier: 'my-package/workspaces/modify-version-differences'

The corresponding event listener class:

use TYPO3\CMS\Core\Utility\DiffUtility;
use TYPO3\CMS\Workspaces\Event\ModifyVersionDifferencesEvent;

final class MyEventListener
{
    public function __construct(protected readonly DiffUtility $diffUtility)
    {
        $this->diffUtility->stripTags = false;
    }

    public function __invoke(ModifyVersionDifferencesEvent $event): void
    {
        $differences = $event->getVersionDifferences();
        foreach($differences as $key => $difference) {
            if ($difference['field'] === 'my_test_field') {
                $differences[$key]['content'] = $this->diffUtility->makeDiffDisplay('a', 'b');
            }
        }

        $event->setVersionDifferences($differences);
    }
}

Impact

It's now possible to modify the version differences of a versioned record, using the new PSR-14 event ModifyVersionDifferencesEvent.