unique_field_ajax.module

<?php

/**
 * @file
 * Unique value for cck fields check module.
 */

use Drupal\Component\Utility\NestedArray;
use Drupal\Core\Entity\ContentEntityType;
use Drupal\Core\Entity\EntityInterface;
use Drupal\Core\Field\BaseFieldDefinition;
use Drupal\Core\Field\Entity\BaseFieldOverride;
use Drupal\Core\Form\FormStateInterface;
use Drupal\Core\Render\Element;
use Drupal\Core\Routing\RouteMatchInterface;
use Drupal\field\Entity\FieldConfig;
use Drupal\Core\Cache\CacheableMetadata;

/**
 * Implements hook_help().
 */
function unique_field_ajax_help($route_name, RouteMatchInterface $route_match) {
  switch ($route_name) {
    // Main module help for the unique_field_ajax module.
    case 'help.page.unique_field_ajax':
      $output = '<h3>' . t('About') . '</h3>';
      $output .= '<p>' . t('The Unique Field module allows administrators to require that content supplied for specified fields is unique.') . '</p>';
      return $output;

    default:
  }
}

/**
 * Implements hook_form_BASE_FORM_ID_alter().
 */
function unique_field_ajax_form_field_config_edit_form_alter(&$form, FormStateInterface $form_state, $form_id) {
  $field = $form_state->getFormObject()->getEntity();
  $unique_field_ajax_types = [
    'string',
    'list_string',
    'text',
    'email',
    'entity_reference',
    'path',
    'uri',
    'link',
  ];
  if (!$field->getFieldStorageDefinition()->isMultiple()) {
    if (in_array($field->getType(), $unique_field_ajax_types)) {
      $form['third_party_settings']['unique_field_ajax'] = array(
        '#type' => 'details',
        '#group' => 'additional_settings',
        '#title' => t('Unique title settings'),
        '#open' => TRUE,
        '#tree' => TRUE,
      );
      $fields = _unique_field_ajax_form_fields($field, 'third_party_settings[unique_field_ajax]');
      if(!empty($fields)) {
        foreach ($fields as $name => $details) {
          $form['third_party_settings']['unique_field_ajax'][$name] = $details;
        }
      }
    }
  }
}

/**
 * Alter forms to add unique title checkbox
 *   - node type add/edit.
 *
 * @param [type] $form
 * @param FormStateInterface $form_state
 * @param [type] $form_id
 *
 * @return void
 */
function unique_field_ajax_form_alter(&$form, FormStateInterface $form_state, $form_id) {
  if (_unique_field_ajax_is_config_form($form_id)) {
    $entity = $form_state->getFormObject()->getEntity();
    $form['unique_field_ajax'] = array(
      '#type' => 'details',
      '#group' => 'additional_settings',
      '#title' => t('Unique title settings'),
      '#open' => TRUE,
      '#tree' => TRUE,
    );
    $fields = _unique_field_ajax_form_fields($entity, 'unique_field_ajax');
    if(!empty($fields)) {
      foreach ($fields as $name => $details) {
        $form['unique_field_ajax'][$name] = $details;
      }
    }
    $form['#entity_builders'][] = '_unique_field_ajax_entity_form_builder';
  }
}

/**
 * Save the third party settings
 *
 * @param $entity_type
 * @param EntityInterface  $entity
 * @param $form
 * @param  \Drupal\Core\Form\FormStateInterface  $form_state
 */
function _unique_field_ajax_entity_form_builder($entity_type, EntityInterface $entity, &$form, FormStateInterface $form_state) {
  $fields = ['unique','per_lang','use_ajax','message'];
  foreach ($fields as $field){
    $value = $form_state->getValue(['unique_field_ajax', $field]);
    if ($value) {
      $entity->setThirdPartySetting('unique_field_ajax', $field, $value);
    }else{
      $entity->unsetThirdPartySetting('unique_field_ajax', $field);
    }
  }
}

/**
 * Attaching data to unique fields.
 *
 * @param $element
 * @param \Drupal\Core\Form\FormStateInterface $form_state
 * @param $context
 */
function unique_field_ajax_field_widget_form_alter(&$element, FormStateInterface $form_state, $context) {
  $field_definition = $context['items']->getFieldDefinition();
  $name = $field_definition->getFieldStorageDefinition()->getName();
  $label = $field_definition->getLabel();

  // alter field widgets to enable unique settings
  if ($field_definition instanceof FieldConfig) {
    $is_unique_per_lang = NULL;
    if ((\Drupal::moduleHandler()
        ->moduleExists('language')) && \Drupal::languageManager()
        ->getCurrentLanguage()
        ->getId()
    ) {
      $is_unique_per_lang = $field_definition->getThirdPartySetting('unique_field_ajax', 'per_lang');
    }
    if ($field_definition->getThirdPartySetting('unique_field_ajax', 'unique')) {
      $main_property_name = $field_definition->getFieldStorageDefinition()->getMainPropertyName();
      $element[$main_property_name]['#unique_field_ajax_settings'] = [
        'per_lang' => $is_unique_per_lang,
        'field_definition' => $field_definition,
        'field_name' => $name,
        'field_label' => $label,
        'message' => $field_definition->getThirdPartySetting('unique_field_ajax', 'message')
      ];

      $element[$main_property_name]['#element_validate'][] = 'unique_field_ajax_validate_unique';
      if ($field_definition->getThirdPartySetting('unique_field_ajax', 'use_ajax')) {
        $element['#process'] = ['_unique_field_ajax_process'];
      }
    }
  }

  // alter title to enable unique settings
  if ($field_definition instanceof BaseFieldDefinition || $field_definition instanceof BaseFieldOverride) {
    $entity = NULL;
    if (isset($context['form']) && isset($context['form']['#type']) && $context['form']['#type'] == 'inline_entity_form') {
        $entity = $context['form']['#default_value'];
    } else { $form_object = $form_state->getFormObject();
      if (method_exists($form_object, 'getEntity')) {
        $entity = $form_object->getEntity();
      }
    }
    if (!$entity) {
      return;
    }

    $entity_type = $entity->getEntityType();
    if (!($entity_type instanceof ContentEntityType) || !$entity_type->hasKey('label')) {
      return;
    }

    $entity_label = $entity_type->getKey('label');
    if ($entity_label !== $name) {
      return;
    }

    $bundle_def_id = $entity_type->getBundleEntityType();
    if (!$bundle_def_id) {
      return;
    }

    $bundle_def = \Drupal::service('entity_type.manager')->getStorage($bundle_def_id)->load($entity->bundle());
    if (!$bundle_def->getThirdPartySetting('unique_field_ajax', 'unique')) {
      return;
    }

    $is_unique_per_lang = NULL;
    if ((\Drupal::moduleHandler()
        ->moduleExists('language')) && \Drupal::languageManager()
        ->getCurrentLanguage()
        ->getId()
    ) {
      $is_unique_per_lang = $field_definition->getThirdPartySetting('unique_field_ajax', 'per_lang');
    }
    $use_ajax = $bundle_def->getThirdPartySetting('unique_field_ajax', 'use_ajax');

    $element['value']['#unique_field_ajax_settings'] = [
      'per_lang' => $is_unique_per_lang,
      'field_definition' => $field_definition,
      'field_name' => $name,
      'field_label' => $entity_label,
      'message' => $bundle_def->getThirdPartySetting('unique_field_ajax', 'message')
    ];
    $element['value']['#element_validate'][] = 'unique_field_ajax_validate_unique';
    if ($use_ajax) {
      $element['#process'] = ['_unique_field_ajax_process'];
    }
  }
}

/**
 * @param array $form
 * @param \Drupal\Core\Form\FormStateInterface $form_state
 * @return mixed
 */
function _unique_field_ajax(array &$form, FormStateInterface $form_state) {
  $element = $form_state->getTriggeringElement();
  return NestedArray::getValue($form, $element['#array_parents']);
}

/**
 * Attach ajax to unique field.
 *
 * @param $element
 * @param \Drupal\Core\Form\FormStateInterface $form_state
 * @param $form
 *
 * @return mixed
 */
function _unique_field_ajax_process($element, FormStateInterface &$form_state, &$form) {
  foreach (Element::children($element) as $property) {
    if (isset($element[$property]) && isset($element[$property]['#unique_field_ajax_settings'])) {

      $field_name = $element[$property]['#unique_field_ajax_settings']['field_name'];
      $unique_field_ajax_settings = $element[$property]['#unique_field_ajax_settings'];

      if ($unique_field_ajax_settings) {
        $field_label = $unique_field_ajax_settings['field_label'];
        $wrapper = 'unique-' . $field_name;
        $form['#attached']['library'][] = 'unique_field_ajax/unique_event';
        $settings = ['id' => '#' . $wrapper . ' input'];
        $form['#attached']['drupalSettings']['unique_field_ajax'][] = $settings;
        $element[$property]['#ajax'] = [
          'callback' => '_unique_field_ajax',
          'event' => 'finishedinput',
          'wrapper' => $wrapper,
          'progress' => [
            'type' => 'throbber',
            'message' => t('Verifying @field_label...',
              ['@field_label' => $field_label]),
          ],
        ];

        $element[$property]['#prefix'] = '<div id="' . $wrapper . '">';
        $element[$property]['#suffix'] = '</div>';
        $value = $form_state->getValue($field_name);
        $value = !empty($value) ? $value[0][$property] : NULL;

        if(!isset($value)) {
          return $element;
        }

        $entity = $form_state->getFormObject()->getEntity();
        $entity_type = $entity->getEntityTypeId();
        $langcode = (!empty($form_state->getValues()['langcode'][0][$property])) ?
          $form_state->getValues()['langcode'][0][$property] : '0';
        $valid = unique_field_ajax_is_unique($entity_type, $langcode,
          $field_name,
          $value, $entity->bundle(),
          $element[$property]['#unique_field_ajax_settings']['per_lang'],
          $entity);
        $message = unique_field_ajax_custom_message($entity, $element, $valid, $property, TRUE);

        if ($valid !== TRUE) {
          $element[$property]['#attributes']['class'][] = 'error';
          $element[$property]['#attributes']['aria-invalid'] = 'true';
          $element[$property]['#suffix'] = '<div class="error">' . $message . '</div>' . $element[$property]['#suffix'];
        }

      }
    }
  }
  return ($element);
}

/**
 * Determine if this is a form for title-able entity config.
 *
 * @param  string  $form_id
 *
 * @return bool
 */
function _unique_field_ajax_is_config_form($form_id) {
  $entity_config_forms = array(
    'node_type_edit_form',
    'node_type_add_form',
  );
  return in_array($form_id, $entity_config_forms);
}


function _unique_field_ajax_form_fields($field, $inputLookup = '') {
  $fields['unique'] = array(
    '#type' => 'checkbox',
    '#title' => t("Unique"),
    '#default_value' => $field->getThirdPartySetting('unique_field_ajax', 'unique'),
    '#weight' => -10,
  );

  $fields['per_lang'] = array(
    '#type' => 'checkbox',
    '#title' => t("Per Language"),
    '#description' => t("Do not allow duplicated content per language"),
    '#default_value' => $field->getThirdPartySetting('unique_field_ajax', 'per_lang'),
    '#weight' => -9,
    '#states' => array(
      'visible' => array(
        ':input[name="'.$inputLookup.'[unique]"]' => array('checked' => TRUE)
      ),
    ),
  );

  $fields['use_ajax'] = array(
    '#type' => 'checkbox',
    '#title' => t("Use Ajax"),
    '#description' => t("Use ajax for validation."),
    '#default_value' => $field->getThirdPartySetting('unique_field_ajax', 'use_ajax'),
    '#weight' => -8,
    '#states' => array(
      'visible' => array(
        ':input[name="'.$inputLookup.'[unique]"]' => array('checked' => TRUE)
      ),
    ),
  );

  $description = t("The message when the value is not unique. The following tokens that can be used:");
  $description .= "<br/>" . t("The placeholder <em>%link</em> can be used to display a link to the entity matching the unique value.");
  $description .= "<br/>" . t("The placeholder <em>%label</em> can be used to display the field label.");
  $fields['message'] = array(
    '#type' => 'textarea',
    '#title' => t("Error message"),
    '#description' => $description,
    '#default_value' => $field->getThirdPartySetting('unique_field_ajax', 'message'),
    '#weight' => -7,
    '#states' => array(
      'visible' => array(
        ':input[name="'.$inputLookup.'[unique]"]' => array('checked' => TRUE)
      ),
    ),
  );

  return $fields;
}

/**
 * Creates the default or custom message.
 *
 * @param $entity
 * @param $element
 * @param $valid
 * @param $property
 * @param $isAjax
 *
 * @return \Drupal\Component\Render\MarkupInterface|string
 * @throws \Drupal\Component\Plugin\Exception\InvalidPluginDefinitionException
 * @throws \Drupal\Component\Plugin\Exception\PluginNotFoundException
 * @throws \Drupal\Core\Entity\EntityMalformedException
 */
function unique_field_ajax_custom_message($entity, $element, $valid, $property, $isAjax) {
  $unique_field_ajax_settings = $isAjax ? $element[$property]['#unique_field_ajax_settings'] : $element['#unique_field_ajax_settings'];
  $field_label = $unique_field_ajax_settings['field_label'];
  $message = $unique_field_ajax_settings['message'];
  $hasNid = $valid !== TRUE && $valid !== "0";

  // default message if nothing set.
  if (empty($message)) {
    $message = t('The field "@field_label" has to be unique.', ['@field_label' => $field_label]);
  }

  // if message contains the string %link look up the matching entities.
  if (strpos($message, '%link') !== FALSE ) {
    $replacement = '<em>' . t('Unknown entity') . '</em>';

    if($hasNid) {
      $entity_with_value = \Drupal::entityTypeManager()
        ->getStorage($entity->getEntityTypeId())
        ->load($valid);

      if ($entity_with_value && $entity_with_value->access('view')) {
        $link = $entity_with_value->toLink(NULL, 'canonical', [
          'attributes' => [
            '_target' => 'blank',
          ],
        ]);
        $replacement = $link->toString();
        $link
          ->getUrl()
          ->toString(TRUE)
          ->applyTo($element);
        CacheableMetadata::createFromObject($entity_with_value)
          ->applyTo($element);
      }
    }

    $message = str_replace('%link', $replacement, $message);
  }

  // replace %label with the field label.
  if (strpos($message, '%label') !== FALSE) {
    $message = str_replace('%label', $field_label, $message);
  }

  return \Drupal\Core\Render\Markup::create($message);
}

/**
 * Element Validate callback to validate a field.
 */
function unique_field_ajax_validate_unique($element, FormStateInterface $form_state, array $form) {
  $field_definition = $element['#unique_field_ajax_settings']['field_definition'];
  $property = $field_definition->getFieldStorageDefinition()->getMainPropertyName();

  $entity = $form_state->getFormObject()->getEntity();
  // If !isset langcode set it to 0.
  $langcode = (
    !empty($form_state->getValues()['langcode'][0]['value']) &&
      $form_state->getValues()['langcode'][0]['value']) ?
      $form_state->getValues()['langcode'][0]['value'] : '0';

  $field_name = $element['#unique_field_ajax_settings']['field_name'];
  $value = $form_state->getValue($field_name);
  $entity_type = $entity->getEntityTypeId();
  $per_lang = $element['#unique_field_ajax_settings']['per_lang'];

  // If field is not unique set error.
  $valid = unique_field_ajax_is_unique($entity_type, $langcode, $field_name, $value[0][$property], $entity->bundle(), $per_lang, $entity);
  $message = unique_field_ajax_custom_message($entity, $element, $valid, $property, FALSE);

  if ($valid !== TRUE) {
    $form_state->setErrorByName($field_name, $message);
    $form_state->setRebuild();
  }
}

/**
 * Test if the field value already exist in the database.
 *
 * @param $entity_type
 * @param $langcode
 * @param $field_name
 * @param $field_value
 * @param $bundle
 * @param $is_unique_per_lang
 *
 * @return bool|string
 *   Boolean TRUE if the value is unique. In any other case, the entity ID of
 *   the entity that has the same value.
 */
function unique_field_ajax_is_unique($entity_type, $langcode, $field_name, $field_value, $bundle, $is_unique_per_lang, $entity) {

  $entity_type_definition = Drupal::entityTypeManager()
    ->getDefinition($entity_type);

  $query = Drupal::entityQuery($entity_type)
    ->range(0, 1)
    ->condition($field_name, $field_value, '=');

  if (!$entity->isNew()) {
    $query->condition($entity_type_definition->getKey('id'), $entity->id(), '<>');
  }

  // Test if the entity has a bundle.
  if (!empty($entity_type_definition->getKey('bundle'))) {
    $query->condition($entity_type_definition->getKey('bundle'), $bundle, '=');
  }

  // Test unique per language.
  if ($is_unique_per_lang) {
    $query->condition('langcode', $langcode);
  }

  $entities = $query->execute();

  if (!empty($entities)) {
    return array_shift($entities);
  }

  return TRUE;
}