<?php

/**
 * Page callback: Diy product settings
 */
function diy_dev_settings_form($form, &$form_state) {

  $form['diy_dev'] = array(
    '#type' => 'fieldset',
    '#title' => t('Aktionen'),
    '#collapsible' => TRUE,
    '#collapsed' => FALSE,
  );

  $form['diy_dev']['dev_trigger'] = array(
    '#type' => 'submit',
    '#value' => 'Nodes vom bundle = "product" mit field_source = "affilinet" löschen',
    '#submit' => array('diy_dev_dev_trigger')
  );

  return system_settings_form($form);
}

/**
 * Dev trigger
 */
function diy_dev_dev_trigger() {

  $query = new EntityFieldQuery();
  $query->entityCondition('entity_type', 'node')
    ->entityCondition('bundle', 'product')
    ->fieldCondition('field_source', 'value', 'affilinet', '=')
    ->addMetaData('account', user_load(1));
  $result = $query->execute();

  if(isset($result['node'])) {
    $nids = array_keys($result['node']);
    node_delete_multiple($nids);
  }
}