Serialize certain endpoint attributes based on conditions

[Moongazer]

Is there a way in t3api v4 to serialize certain attributes conditionally, for example only if a valid FE user exists? To clarify: let's say we have an endpoint /test responding an item {"attributeForEveryone": "Hello world"}.

Now, if a valid FE user exists, we'd like do show an extra additional attribute like {"attributeForEveryone": "Hello world", "visibleOnlyToUsers": "Cool that you are on board!"} (The additional attribute is not user-related/personalized).

I found a similar question with solution here, but it is a bit old, so not sure if that is still the way to go, or if this solution is the right way to implement this requirement.

Is there a way to achieve this? And maybe there is even an existing implementation somewhere in t3api core to look at, or in other public extension too look how this works?

I'd highly appreciate any helpful feedback! 🙏

[kszymukowicz]

As example I can put you some code that worked in previous versions of t3api.
You can for sure change it to be compatible with v4.

ext_localconf.php

$signalSlotDispatcher = \TYPO3\CMS\Core\Utility\GeneralUtility::makeInstance(\TYPO3\CMS\Extbase\SignalSlot\Dispatcher::class);
$signalSlotDispatcher->connect(
    \SourceBroker\T3api\Serializer\ContextBuilder\ContextBuilderInterface::class,
    \SourceBroker\T3api\Serializer\ContextBuilder\ContextBuilderInterface::SIGNAL_CUSTOMIZE_SERIALIZER_CONTEXT_ATTRIBUTES,
    \V\Local\Slot\T3apiAddFeUserGroupsToSerializationGroups::class,
    'execute'
);

T3apiAddFeUserGroupsToSerializationGroups.php

<?php
declare(strict_types=1);
namespace V\Local\Slot;

use SourceBroker\T3api\Domain\Model\AbstractOperation;
use Symfony\Component\HttpFoundation\Request;
use TYPO3\CMS\Core\Utility\GeneralUtility;

class T3apiAddFeUserGroupsToSerializationGroups
{
    public function execute(AbstractOperation $operation, Request $request, array $attributes): array
    {
        $feUser = $GLOBALS['TSFE']->fe_user && $GLOBALS['TSFE']->fe_user->user ? $GLOBALS['TSFE']->fe_user->user : null;

        if ($feUser && $feUser['usergroup']) {
            $userGroupIds = GeneralUtility::intExplode(',', $feUser['usergroup']);

            $groups = $attributes['groups'] ?? [];
            foreach ($groups as $group) {
                foreach ($userGroupIds as $userGroupId) {
                    $attributes['groups'][] = $group . '__current_user_fegroup:' . $userGroupId;
                }
            }
        }

        return [
            'operation' => $operation,
            'request' => $request,
            'attributes' => $attributes,
        ];
    }
}

then in model

    /**
     * @T3api\Serializer\Groups({
     *     "api_user_get_current_item",
     *     "api_user_get_item__current_user_fegroup:14",
     *     "api_user_get_collection__current_user_fegroup:14",
     * })
     */
    protected $specialField = '';
    

[Moongazer]

Amazing! Thank you VERY much for the fast and helpful answer, that works flawless 😊 The flexibility of this extension is really mind-blowing.

Here is the adapted solution for everyone using the newer versions:

  Vendor\MyExt\EventListener\AddFeUserGroupsToSerializationGroups:
    tags:
      - name: event.listener
        identifier: 'vendor-myext/AddFeUserGroupsToSerializationGroups'

<?php

namespace Vendor\MyExt\EventListener;

use SourceBroker\T3api\Event\AfterCreateContextForOperationEvent;
use TYPO3\CMS\Core\Utility\GeneralUtility;

class AddFeUserGroupsToSerializationGroups
{
    public function __invoke(AfterCreateContextForOperationEvent $createContextForOperationEvent): void
    {
        $feUser = $GLOBALS['TSFE']->fe_user->user ?? null;

        if ($feUser && $feUser['usergroup']) {
            $userGroupIds = GeneralUtility::intExplode(',', $feUser['usergroup']);
            $context = $createContextForOperationEvent->getContext();
            $groups = $context->getAttribute('groups');

            foreach ($groups as $group) {
                foreach ($userGroupIds as $userGroupId) {
                    $groups[] = $group . '__current_user_usergroup:' . $userGroupId;
                }
            }

            $context->setAttribute('groups', $groups);
        }
    }
}