entity_browser.module

<?php

/**
 * @file
 * Allows to flexibly create, browse and select entities.
 */

use \Drupal\Core\Form\FormStateInterface;
use \Drupal\Core\Render\Element;
use Drupal\Core\Url;

/**
 * Implements hook_theme().
 *
 * Overrides the core html theme to use a custom template for iframes.
 */
function entity_browser_theme() {
  return [
    'html__entity_browser__iframe' => [
      'template' => 'html--entity-browser--iframe',
      'render element' => 'html',
      'preprocess functions' => ['template_preprocess_html']
    ],
    'html__entity_browser__modal' => [
      'template' => 'html--entity-browser--iframe',
      'render element' => 'html',
      'preprocess functions' => ['template_preprocess_html']
    ],
    'page__entity_browser__iframe' => [
      'template' => 'page--entity-browser--iframe',
      'render element' => 'html',
      'preprocess functions' => ['template_preprocess_page']
    ],
    'page__entity_browser__modal' => [
      'template' => 'page--entity-browser--iframe',
      'render element' => 'html',
      'preprocess functions' => ['template_preprocess_page']
    ],
  ];
}

/**
 * Implements hook_form_alter().
 */
function entity_browser_form_alter(&$form, FormStateInterface &$form_state) {
  $entity_browser_dialog_edit = \Drupal::service('request_stack')->getCurrentRequest()->get('_route');
  if ($entity_browser_dialog_edit == 'entity_browser.edit_form') {
    // Let's allow the save button only.
    foreach (Element::children($form['actions']) as $key) {
      $form['actions'][$key]['#access'] = $key == 'submit';
    }
    // Use Ajax.
    $form['actions']['submit']['#ajax'] = [
      'url' => Url::fromRoute('entity_browser.edit_form', ['entity_type' => $form_state->getFormObject()->getEntity()->getEntityTypeId(), 'entity' => $form_state->getFormObject()->getEntity()->id()])
    ];
  }
}

/**
 * Implements hook_preprocess_page__entity_browser__iframe().
 *
 * Tries to figure out where messages block lives and display it separately.
 */
function entity_browser_preprocess_page__entity_browser__iframe(&$variables) {
  $variables['messages'] = '';
  $blocks = \Drupal::entityTypeManager()->getStorage('block')->loadByProperties([
    'theme' => \Drupal::theme()->getActiveTheme()->getName(),
    'plugin' => 'system_messages_block',
  ]);

  if (($messages = current($blocks)) && !empty($variables['page'][$messages->getRegion()][$messages->id()])) {
    $variables['messages'] = $variables['page'][$messages->getRegion()][$messages->id()];
  }
}

/**
 * Implements hook_preprocess_page__entity_browser__modal().
 *
 * Tries to figure out where messages block lives and display it separately.
 */
function entity_browser_preprocess_page__entity_browser__modal(&$variables) {
  entity_browser_preprocess_page__entity_browser__iframe($variables);
}