Breaking: #102605 - TSFE->fe_user removed

See forge#102605

Description

Frontend-related property TypoScriptFrontendController->fe_user has been removed.

When looking at the TYPO3 frontend rendering chain, class TypoScriptFrontendController is by far the biggest technical debt: It mixes a lot of concerns and carries tons of state and functionality that should be modeled differently, which leads to easier to understand and more flexible code. The class is shrinking since various major versions already and will ultimately dissolve entirely at some point. Changes in this area are becoming more aggressive with TYPO3 v13. Any code using the class will need adaptions at some point, single patches will continue to communicate alternatives.

In case of the fe_user property, two alternatives exist: The frontend user can be retrieved from the PSR-7 request attribute frontend.user, and basic frontend user information is available using the Context aspect frontend.user.

Note accessing TypoScript TSFE:fe_user details continues to work for now, using for example lib.foo.data = TSFE:fe_user|user|username to retrieve the username of a logged in user is still ok.

Impact

Using TypoScriptFrontendController->fe_user (or $GLOBALS['TSFE']->fe_user) will raise a PHP fatal error.

Affected installations

Instances with extensions dealing with frontend user details may be affected, typically custom login extensions or extensions consuming detail data of logged in users.

Migration

There are two possible migrations.

First, a limited information list of frontend user details can be retrieved using the Context aspect frontend.user in frontend calls. See class \TYPO3\CMS\Core\Context\UserAspect for a full list. The current context can retrieved using dependency injection. Example:

use TYPO3\CMS\Core\Context\Context;

final class MyExtensionController {
    public function __construct(
        private readonly Context $context,
    ) {}

    public function myAction() {
        $frontendUserUsername = $this->context->getPropertyFromAspect('frontend.user', 'username', ''));
    }
}

Additionally, the full \TYPO3\CMS\Frontend\Authentication\FrontendUserAuthentication object is available as request attribute frontend.user in the frontend. Note some details of that object are marked @internal, using the context aspect is thus the preferred way. Example of an extension using Extbase's ActionController:

final class MyExtensionController extends ActionController {
    public function myAction() {
        // Note the 'user' property is marked @internal.
        $frontendUserUsername = $this->request->getAttribute('frontend.user')->user['username'];
    }
}