TYPO3 - how to get FE UID via Viewhelper - php

Question

How can I fetch and render the uid of the FE User via a Viewhelper? The below is working via a Controller ... but not in a Viewhelper. Where is the difference? I'm using 7.6.11 and at the end I would like to have the uid of the FE User and the usergroup uid of him and further use it in the html of the extension and in general partials ...
/typo3conf/ext/extension/Classes/ViewHelpers/UserViewHelper.php
<?php
namespace Vendor\Extension\ViewHelpers;
class UserViewHelper extends \TYPO3\CMS\Fluid\Core\ViewHelper\AbstractViewHelper {
/**
* User Repository
*
* #var \TYPO3\CMS\Extbase\Domain\Repository\FrontendUserRepository
* #inject
*/
protected $userRepository;
/**
* #var \TYPO3\CMS\Extbase\Domain\Repository\FrontendUserGroupRepository
* #inject
*/
protected $frontendUserGroupRepository;
public function render() {
$userIDTest = $this->userRepository->findByUid($GLOBALS['TSFE']->fe_user->user['uid']);
$this->view->assign('userIDTest', $userIDTest);
}
}
List.html
<f:layout name="Default" />
<f:section name="main">
{userIDTest.uid}
</f:section>
As suggested by Dimitry I replaced
$this->view->assign('userIDTest', $userIDTest);
with
return $userIDTest;
And in List.html I have this:
{namespace custom=Vendor\Extension\ViewHelpers}
<f:layout name="Default" />
<f:section name="main">
<f:alias map="{user: '{custom:user()}'}">
{user.uid} {user.username}
</f:alias>
</f:section>
... and after clearing all Caches (FE/BE/Install) and deleting typo3temp ... now its working!

Answer 1

In 7.x and upwards ViewHelpers are compiled, resulting in the render method being called only once for compiling. Afterwards, only the static method renderStatic() is called. You could overwrite renderStatic, it will be called every time:
<?php
namespace Vendor\Extension\ViewHelpers;
use TYPO3\CMS\Fluid\Core\ViewHelper\AbstractViewHelper;
class UserIdViewHelper extends AbstractViewHelper
{
public function render()
{
return static::renderStatic(
[],
$this->renderChildrenClosure,
$this->renderingContext
);
}
public static function renderStatic(
array $arguments,
\Closure $renderChildrenClosure,
RenderingContextInterface $renderingContext
) {
$userData = $GLOBALS['TSFE']->fe_user->user;
return null !== $userData ? (int)$userData['uid'] : null;
}
}
If you need to use some service in your ViewHelper, things get more complicated, since dependency injection won't work with compiled ViewHelpers. You need to get an object manager, and fetch an instance of the service with the object manager.
This could look like this, assuming you would want to use the FrontendUserRepository as service, because you want to return the entire user object, not only the users uid:
<?php
namespace Vendor\Extension\ViewHelpers;
use TYPO3\CMS\Core\Utility\GeneralUtility;
use TYPO3\CMS\Extbase\Domain\Repository\FrontendUserRepository;
use TYPO3\CMS\Extbase\Object\ObjectManager;
use TYPO3\CMS\Fluid\Core\ViewHelper\AbstractViewHelper;
class UserViewHelper extends AbstractViewHelper
{
/**
* #var FrontendUserRepository
*/
private static $frontendUserRepository = null;
public function render()
{
return static::renderStatic(
[],
$this->renderChildrenClosure,
$this->renderingContext
);
}
public static function renderStatic(
array $arguments,
\Closure $renderChildrenClosure,
RenderingContextInterface $renderingContext
) {
$userData = $GLOBALS['TSFE']->fe_user->user;
if (null === $userData) {
return null;
}
return static::getFrontendUserRepository()->findByUid((int)$userData['uid']);
}
private static function getFrontendUserRepository()
{
if (null === static::$frontendUserRepository) {
$objectManager = GeneralUtility::makeInstance(ObjectManager::class);
static::$frontendUserRepository = $objectManager->get(FrontendUserRepository::class);
}
return static::$frontendUserRepository;
}
}
Disclaimer: All the code is written without actually running it, thus there are bugs in it.

Answer 2

if you want to return the user or the uid of the user in the viewhelper, just return it.
instead of
$this->view->assign('userIDTest', $userIDTest);
do this
return $userIDTest;
In your fluid you can use the user variables in different ways. The easiest one is to use the "alias" viewhelper: https://fluidtypo3.org/viewhelpers/fluid/master/AliasViewHelper.html
<f:alias map="{user: '{namespace:user()}'}">
{user.uid} {user.username}
</f:alias>