Issue #3500732 by mysdiir: Action that combines two lists.

Closes #3500732

modules/base/src/Plugin/Action/ListMerge.php

+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\eca_base\Plugin\Action;
+
+use Drupal\Core\Access\AccessResult;
+use Drupal\Core\Form\FormStateInterface;
+use Drupal\Core\Session\AccountInterface;
+use Drupal\eca\Plugin\Action\ListDataOperationBase;
+use Drupal\eca\Plugin\DataType\DataTransferObject;
+
+/**
+ * Action to count items in a list and store resulting number as token.
+ *
+ * @Action(
+ *   id = "eca_list_combine",
+ *   label = @Translation("List: merge"),
+ *   description = @Translation("Merges two lists into a new one."),
+ *   eca_version_introduced = "2.1.6",
+ * )
+ */
+class ListMerge extends ListDataOperationBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  public function defaultConfiguration(): array {
+    return [
+      'merged_list' => '',
+      'list_token_left' => '',
+      'list_token_right' => '',
+    ] + parent::defaultConfiguration();
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function buildConfigurationForm(array $form, FormStateInterface $form_state): array {
+    $form['merged_list'] = [
+      '#type' => 'textfield',
+      '#title' => $this->t('Token name'),
+      '#description' => $this->t('The name of the new token, containing the combined list.'),
+      '#default_value' => $this->configuration['merged_list'],
+      '#weight' => -20,
+      '#required' => TRUE,
+      '#eca_token_reference' => TRUE,
+    ];
+    $form['list_token_left'] = [
+      '#type' => 'textfield',
+      '#title' => $this->t('Token name of first list'),
+      '#description' => $this->t('Token name of the first list that should be combined into a new one.'),
+      '#default_value' => $this->configuration['list_token_left'],
+      '#weight' => -15,
+      '#required' => TRUE,
+      '#eca_token_reference' => TRUE,
+    ];
+    $form['list_token_right'] = [
+      '#type' => 'textfield',
+      '#title' => $this->t('Token name of second list'),
+      '#description' => $this->t('Token name of the second list that should be combined into a new one.'),
+      '#default_value' => $this->configuration['list_token_right'],
+      '#weight' => -10,
+      '#required' => TRUE,
+      '#eca_token_reference' => TRUE,
+    ];
+
+    return $form;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function submitConfigurationForm(array &$form, FormStateInterface $form_state): void {
+    $this->configuration['merged_list'] = $form_state->getValue('merged_list');
+    $this->configuration['list_token_left'] = $form_state->getValue('list_token_left');
+    $this->configuration['list_token_right'] = $form_state->getValue('list_token_right');
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function access($object, ?AccountInterface $account = NULL, $return_as_object = FALSE) {
+    if ($account === NULL) {
+      $account = $this->currentUser;
+    }
+    $list_left_token_raw = $this->tokenService->getTokenData($this->configuration['list_token_left']);
+    $list_right_token_raw = $this->tokenService->getTokenData($this->configuration['list_token_right']);
+
+    if (!is_array($list_left_token_raw) && !($list_left_token_raw instanceof \Traversable)) {
+      $access_result = AccessResult::forbidden('The left token does not provide an iterable list.');
+    }
+    elseif (!is_array($list_right_token_raw) && !($list_right_token_raw instanceof \Traversable)) {
+      $access_result = AccessResult::forbidden('The right token does not provide an iterable list.');
+    }
+    else {
+      $access_result = AccessResult::allowed();
+    }
+
+    return $return_as_object ? $access_result : $access_result->isAllowed();
+  }
+
+  /**
+   * Converts the given value into an array if necessary.
+   *
+   * @param mixed $value
+   *   The value to be converted.
+   *
+   * @return array
+   *   The converted array.
+   */
+  private function normalizeToArray(mixed $value): array {
+    if ($value instanceof DataTransferObject) {
+      return $value->toArray();
+    }
+    if ($value instanceof \Traversable) {
+      return iterator_to_array($value);
+    }
+    return (array) $value;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function execute(): void {
+    $list_left_token_raw = $this->tokenService->getTokenData($this->configuration['list_token_left']);
+    $list_right_token_raw = $this->tokenService->getTokenData($this->configuration['list_token_right']);
+
+    $list_left_token = $this->normalizeToArray($list_left_token_raw);
+    $list_right_token = $this->normalizeToArray($list_right_token_raw);
+
+    $combined_list = array_merge($list_left_token, $list_right_token);
+
+    $this->tokenService->addTokenData($this->configuration['merged_list'], $combined_list);
+  }
+
+}