PSR-14 events

Target group: Developers

Table of Contents

Introduction

You can enhance the functionality in the schema extension with PSR-14 event listeners. An event listener receives an event that provides methods for retrieving and setting dedicated properties.

Render additional types

Changed in version 3.11.0

This event is available in older versions, but is now official API.

The event allows to add markup in cases where no controller is available, for example, if you want to enrich a page with structured data depending on the doktype of a page.

The event \Brotkrueml\Schema\Event\RenderAdditionalTypesEvent provides the following methods:

getRequest(): \Psr\Http\Message\ServerRequestInterface: Returns the PSR-7 request object.

addType(TypeInterface ...$type): void: Add one or more type models.

addMainEntityOfWebPage(TypeInterface $mainEntity): void: Add a main entity.

Example

In the example we add structured data markup depending on the doktype of the page.

Create the event listener

EXT:my_extension/Classes/EventListener/AddMarkupToArticlePages.php

<?php

declare(strict_types=1);

namespace MyVendor\MyExtension\EventListener;

use Brotkrueml\Schema\Event\RenderAdditionalTypesEvent;
use Brotkrueml\Schema\Type\TypeFactory;
use TYPO3\CMS\Frontend\Page\PageInformation;

final class AddMarkupToArticlePages
{
    public function __construct(
        private readonly TypeFactory $typeFactory,
    ) {}

    public function __invoke(RenderAdditionalTypesEvent $event): void
    {
        // The "frontend.page.information" attribute is available since TYPO3 v13.
        // Use the "frontend.controller" attribute (TSFE) in older TYPO3 versions
        // to retrieve the page record.
        /** @var PageInformation $pageInformation */
        $pageInformation = $event->getRequest()->getAttribute('frontend.page.information');
        $page = $pageInformation->getPageRecord();
        if ($page['doktype'] !== 12345) {
            return;
        }

        // Only for doktype 12345
        $article = $this->typeFactory->create('Article');
        $article->setProperty('name', $page['title']);
        // ... and set some other properties

        $event->addType($article);
    }
}

The method __invoke() implements the logic for rendering additional types. It receives the RenderAdditionalTypesEvent. You can add as many types as you like.

Register your event listener in Configuration/Services.yaml

services:
   # Place here the default dependency injection configuration

   MyVendor\MyExtension\EventListener\AddMarkupToArticlePages:
      tags:
         - name: event.listener
           identifier: 'my-extension/add-markup-to-article-pages'

Read how to configure dependency injection in extensions.

Register additional properties for a type

Deprecated since version 3.10.0

This way to extend a type with additional properties has been deprecated and will stop working with schema v4.

Sometimes it can be necessary to use properties which are not standardised or pending, or to add property annotations. Therefore an PSR-14 event is available which can be used in an event listener.

These additional properties are not only available in the API but also as arguments in the view helpers.

The event \Brotkrueml\Schema\Event\RegisterAdditionalTypePropertiesEvent provides the following methods:

getType(): string: Returns the class name of the type. You can use this to add a property only to one type.

getAdditionalProperties(): array: Retrieve the already defined additionalProperties for this type, for example, by other event listeners.

registerAdditionalProperty(string $propertyName): void: This method registers an additional property for one or more types.

Example

Create the event listener

EXT:my_extension/Classes/EventListener/AdditionalPropertiesForPerson.php

<?php

declare(strict_types=1);

namespace MyVendor\MyExtension\EventListener;

use Brotkrueml\Schema\Event\RegisterAdditionalTypePropertiesEvent;
use Brotkrueml\Schema\Model\Type\Person;

final class AdditionalPropertiesForPerson
{
    public function __invoke(RegisterAdditionalTypePropertiesEvent $event): void
    {
        if ($event->getType() === Person::class) {
            $event->registerAdditionalProperty('gender');
            $event->registerAdditionalProperty('jobTitle');
        }
    }
}

The method __invoke() implements the logic for registering additional properties for one or more types. It receives the RegisterAdditionalTypePropertiesEvent. You can register as many properties as you want.

Register your event listener in Configuration/Services.yaml

services:
   # Place here the default dependency injection configuration

   MyVendor\MyExtension\EventListener\AdditionalPropertiesForPerson:
      tags:
         - name: event.listener
           identifier: 'my-extension/additional-properties-for-person'

Read how to configure dependency injection in extensions.