title: Which files are needed for an own finisher to work in the Typo3 form extension?
body: <p>I want to make my own finisher but I don't have a clue what is needed.</p>
  <p>I have
  \Domain\Finishers\MyOwnFinisher.php // with the finisher class
  Configuration\Form\Backend.yaml //which should tell my TYPO3 where to look for the finisher
  Configuration\TypoScript\setup.typoscript //telling EXT:form where the Backend.yaml is</p>
  <p>but still I get an exception:
  &quot;The finisher preset identified by “xxx” could not be found, or the implementationClassName was not specified.&quot;</p>
  <p>Is there some file I forgot? Some configuration I must set?</p>
  <p><em>Backend.yaml</em></p>
  <pre><code>prototypes:
    standard:
      finishersDefinition:
        MyOwn:
          implementationClassName: 'mastar\testprivateext\Classes\Domain\Finishers\MyOwnFinisher'
          options:
            table: tx_testprivateext_domain_model_YetAnotherTable
  </code></pre>
  <p><em>setup.typoscript</em></p>
  <pre><code>@import &quot;EXT:testprivateext/Configuration/TypoScript/Setup/*.typoscript&quot;
  
  plugin.tx_form.settings.yamlConfigurations {
    901 = EXT:testprivateext/Configuration/Form/Backend.yaml
  }
  </code></pre>
  <p><em>MyOwnFinisher.php</em></p>
  <pre><code>&lt;?php 
  
  declare(strict_types=1);
  
  namespace mastar\testprivateext\Classes\Domain\Finishers;
   
  use TYPO3\CMS\Core\Database\ConnectionPool;
  use TYPO3\CMS\Core\Utility\GeneralUtility;
  use TYPO3\CMS\Extbase\Domain\Model\FileReference;
  use TYPO3\CMS\Form\Domain\Finishers\Exception\FinisherException;
  use TYPO3\CMS\Form\Domain\Model\FormElements\FormElementInterface;
  use TYPO3\CMS\Form\Domain\Finishers\AbstractFinisher;
  
  class MyOwnFinisher extends AbstractFinisher {
      protected $defaultOptions = [
          'table' =&gt; 'tx_testprivateext_domain_model_YetAnotherTable',
          'pid' =&gt; '34',
          'name' =&gt; '',
          'unterzeile' =&gt; '',
          'strasse' =&gt; '',
          'hausnummer' =&gt; '',
          'plz' =&gt; '',
          'ort' =&gt; '',
          'telefon' =&gt; '',
          'fax' =&gt; '',
          'web' =&gt; '',
      ];
  
      protected $shortFinisherIdentifier = 'MyOwn';
      protected $databaseConnection;
  
      protected function executeInternal() {
          /// Stuff get's done here
      }
  }
  </code></pre>
  <p>Thanks in advance!</p>