form_placeholder.module in Form Placeholder 8

Use field label as placeholder for all elements in chosen form.

File

form_placeholder.module

<?php

/**
 * @file
 * Use field label as placeholder for all elements in chosen form.
 */

/**
 * Implements hook_element_info_alter().
 */
function form_placeholder_element_info_alter(array &$types) {
  foreach (array_keys($types) as $type) {
    $allowed_types = [
      'form',
      'textarea',
      'textfield',
      'tel',
      'email',
      'url',
      'number',
      'password',
      'password_confirm',
    ];
    if (in_array($type, $allowed_types)) {
      $types[$type]['#process'][] = 'form_placeholder_process_element';
    }
  }
}

/**
 * Element process callback.
 *
 * @param array $element
 *   The render array element.
 * @param \Drupal\Core\Form\FormStateInterface $form_state
 *   The FormStateInterface object for this form
 *
 * @return array
 *   The processed element.
 */
function form_placeholder_process_element($element, &$form_state) {
  $form = $form_state
    ->getCompleteForm();
  $form_placeholder = NULL;
  if (isset($element['#form_placeholder'])) {
    $form_placeholder = $element['#form_placeholder'];
  }
  elseif (isset($form['#form_placeholder'])) {
    $form_placeholder = $form['#form_placeholder'];
  }
  if (!is_null($form_placeholder)) {
    $action = $form_placeholder == TRUE ? 'include' : 'exclude';
    if ($element['#type'] == 'form') {
      $element['#attributes']['class'][] = 'form-placeholder-' . $action . '-children';
    }
    else {
      $element['#attributes']['class'][] = 'form-placeholder-' . $action;
    }
  }
  form_placeholder_attach($element);
  return $element;
}

/**
 * Adds placeholder to form element.
 *
 * @param array $element
 *   Form API element.
 */
function form_placeholder_attach(&$element) {
  $config = \Drupal::config('form_placeholder.settings');

  // Adding settings.
  $whitechars = [
    "\r\n",
    "\r",
    "\n",
  ];
  $element['#attached']['drupalSettings']['form_placeholder'] = [
    'include' => str_replace($whitechars, ',', $config
      ->get('included_selectors')),
    'exclude' => str_replace($whitechars, ',', $config
      ->get('excluded_selectors')),
    'required_indicator' => $config
      ->get('required_indicator'),
  ];

  // Adding module JS file.
  $element['#attached']['library'][] = 'form_placeholder/form_placeholder';
}

Functions

Name	Description
form_placeholder_attach	Adds placeholder to form element.
form_placeholder_element_info_alter	Implements hook_element_info_alter().
form_placeholder_process_element	Element process callback.