Developer corner¶

Target group: Developers

Table of Contents

Writing own variable resolvers¶

With variables it is possible to add information to a process start which is resolved when submitting a form. This extension ships some variable resolvers already, e.g. for translation or language information.

You can write your own variable resolvers dependent on your needs. Variable resolvers are implemented as PSR-14 event listeners.

The event listener receives the event JobRouter\AddOn\Typo3Base\Event\ResolveFinisherVariableEvent. It provides the following methods:

getFieldType(): \JobRouter\AddOn\Typo3Base\Enumeration\FieldType

Changed in version 2.0.0

Get the field type, like FieldType::Text for text or FieldType::Integer for int. Have a look in the class JobRouter\AddOn\Typo3Base\Enumeration\FieldType for the available field types.

getValue(): string

Get the current value of the field. One or more variables can be defined inside.

setValue(string $value): void

Set the new value after resolving one or more variables.

getCorrelationId(): string

Get the current correlation ID.

getFormValues(): array

Get the form values, e.g. ['company' => 'Acme Ltd.', 'name' => 'John Smith'].

getRequest(): \\Psr\\Http\\Message\\ServerRequestInterface

Get the current request.

Hint

Some variable resolvers are already shipped with the extension. Have a look into the folder Classes/Domain/VariableResolver for implementation details.

Example¶

As an example we want to resolve a variable to a cookie value.

Create the event listener

<?php
declare(strict_types=1);

namespace YourVender\YourExtension\EventListener;

use JobRouter\AddOn\Typo3Base\Event\ResolveFinisherVariableEvent;
use Psr\Http\Message\ServerRequestInterface;

final class TheCookieVariableResolver
{
   private const COOKIE_NAME = 'the_cookie';
   private const VARIABLE = '{__theCookieValue}';

   public function __invoke(ResolveFinisherVariableEvent $event): void
   {
      $value = $event->getValue();

      if (str_pos($value, self::VARIABLE) === false) {
         // Variable is not available, do nothing
         return;
      }

      $cookies = $event->getRequest()->getCookieParams();

      $variableValue = $cookies[self::COOKIE_NAME] ?? '';
      $value = str_replace(self::VARIABLE, $variableValue, $value);

      $event->setValue($value);
   }
}

Important

Variables have to start with {__. Otherwise the variable resolver is not called for a value.

Register your event listener in Configuration/Services.yaml

services:
   YourVendor\YourExtension\EventListener\TheCookieVariableResolver:
      tags:
         - name: event.listener
           identifier: 'your-extension/cookie-variable-resolver'
           event: JobRouter\AddOn\Typo3Base\Event\ResolveFinisherVariableEvent