image_replace.module in Image Replace 8

Provides an image style effect replacing the whole image with another one.

File

image_replace.module

<?php

/**
 * @file
 * Provides an image style effect replacing the whole image with another one.
 */
use Drupal\Component\Utility\Html;
use Drupal\Core\Entity\ContentEntityInterface;
use Drupal\Core\Entity\EntityInterface;
use Drupal\field\Entity\FieldConfig;
use Drupal\field\Entity\FieldStorageConfig;
use Drupal\image\Entity\ImageStyle;
use Drupal\image\ImageStyleInterface;

/**
 * Implements hook_form_FORM_ID_alter() for 'field_config_edit_form'.
 *
 * Add per image-field instance settings for image style replacement.
 */
function image_replace_form_field_config_edit_form_alter(&$form, &$form_state, $form_id) {
  $field = $form_state
    ->getFormObject()
    ->getEntity();
  if ($field
    ->getType() == 'image') {
    $form['third_party_settings']['image_replace'] = [
      '#type' => 'fieldset',
      '#collapsible' => TRUE,
      '#collapsed' => TRUE,
      '#title' => t('Image replace'),
      '#description' => t('Use another image when rendered with certain image styles.'),
      '#weight' => 99,
      '#tree' => TRUE,
      '#element_validate' => [
        'image_replace_form_field_config_edit_form_element_validate',
      ],
    ];
    $image_field_options = array_map(function ($replacement_field) {
      return $replacement_field
        ->label();
    }, _image_replace_image_fields($field
      ->getTargetEntityTypeId(), $field
      ->getTargetBundle()));
    unset($image_field_options[$field
      ->getName()]);
    $image_style_map = $field
      ->getThirdPartySetting('image_replace', 'image_style_map', []);
    foreach (_image_replace_style_options() as $image_style => $label) {
      $default_value = isset($image_style_map[$image_style]['source_field']) ? $image_style_map[$image_style]['source_field'] : NULL;
      $form['third_party_settings']['image_replace']['image_style_map'][$image_style]['source_field'] = [
        '#type' => 'select',
        '#title' => $label,
        '#description' => t('The image field to use as a source when rendered with the %style image style.', [
          '%style' => $label,
        ]),
        '#options' => $image_field_options,
        '#default_value' => $default_value,
        '#empty_value' => FALSE,
      ];
      if ($default_value) {
        $form['third_party_settings']['image_replace']['#collapsed'] = FALSE;
      }
    }
  }
}

/**
 * Form element validation callback.
 *
 * Displays a warning when replacement mapping is changed for fields with
 * existing content.
 */
function image_replace_form_field_config_edit_form_element_validate($element, &$form_state, $form) {
  $field = $form_state
    ->getFormObject()
    ->getEntity();
  $field_storage = FieldStorageConfig::loadByName($field
    ->getTargetEntityTypeId(), $field
    ->getName());
  if ($field_storage
    ->hasData()) {
    $changed = FALSE;
    foreach (array_keys(_image_replace_style_options()) as $image_style) {
      $current_value = $element['image_style_map'][$image_style]['source_field']['#default_value'];
      $new_value = $element['image_style_map'][$image_style]['source_field']['#value'];
      if (!(empty($current_value) && empty($new_value)) && $current_value != $new_value) {
        $changed = TRUE;
        break;
      }
    }
    if ($changed) {
      $messenger = \Drupal::messenger();
      $messenger
        ->addWarning(t('The image replacement settings have been modified. As a result, it is necessary to rebuild the image replacement mapping for existing content. Note: The replacement mapping is updated automatically when saving an entity. Content can be resaved in bulk using the <em>save content</em> of the <a href="@content_url">administrative interface</a>', [
        '@content_url' => '/admin/content',
      ]));
      $messenger
        ->addWarning(t('Also note that images already might be cached in the browser or by any intermediate HTTP cache. On live sites the only way to force browsers to redownload a cached image is to reupload the image with a different name.'));
    }
  }
}

/**
 * Implements hook_field_attach_presave().
 *
 * Insert image mappings into the image replace table when entities are saved.
 */
function image_replace_entity_presave(EntityInterface $entity) {
  if (!$entity instanceof ContentEntityInterface) {
    return;
  }

  // Collect involved image fields and target mapping from image instance
  // settings.
  $involved_fields = [];
  $target_map = [];
  foreach (_image_replace_image_fields($entity
    ->getEntityTypeId(), $entity
    ->bundle()) as $target_field => $field) {
    if ($field && ($source_map = $field
      ->getThirdPartySetting('image_replace', 'image_style_map', []))) {
      $involved_fields[$target_field] = $target_field;
      foreach ($source_map as $target_style => $record) {
        $source_field = $record['source_field'];
        $target_map[$target_field][$target_style] = $source_field;
        $involved_fields[$source_field] = $source_field;
      }
    }
  }

  // Extract all uris from all involved image fields.
  $uri_map = [];
  foreach ($involved_fields as $field_name) {
    $uri_map[$field_name] = [];
    if (!empty($entity->{$field_name})) {
      foreach ($entity->{$field_name} as $image) {
        $uri_map[$field_name][] = $image->entity
          ->getFileUri();
      }
    }
  }

  // Synchronize image replacement entries.
  $storage_service = \Drupal::service('image_replace.storage');
  foreach ($target_map as $target_field => $source_map) {
    foreach ($source_map as $target_style => $source_field) {
      foreach ($uri_map[$target_field] as $delta => $target_uri) {
        $storage_service
          ->remove($target_style, $target_uri);
        if (isset($uri_map[$source_field][$delta])) {
          $storage_service
            ->add($target_style, $target_uri, $uri_map[$source_field][$delta]);
        }
      }
    }
  }

  // Flush derived images.
  foreach ($uri_map as $uris) {
    foreach ($uris as $uri) {
      image_path_flush($uri);
    }
  }
}

/**
 * Implements hook_ENTITY_TYPE_presave().
 *
 * Save image style name into replace effect settings in order to make the style
 * name available from within image_replace_effect callback.
 */
function image_replace_image_style_presave(ImageStyleInterface $image_style) {
  $effects = $image_style
    ->get('effects');
  foreach ($image_style
    ->get('effects') as $key => $effect) {
    if ($effect['id'] == 'image_replace') {
      $effects[$key]['data']['image_style'] = $image_style
        ->getName();
    }
  }
  $image_style
    ->set('effects', $effects);
}

/**
 * Collect info for all image field instances on a given entity_type/bundle.
 *
 * @param string $entity_type
 *   The entity type, e.g. node, for which the info shall be returned.
 * @param string $bundle
 *   The bundle name for which to return instances.
 *
 * @return array
 *   An associative array of instance arrays keyed by the field name.
 */
function _image_replace_image_fields($entity_type, $bundle) {
  $image_fields = [];
  $field_definitions = \Drupal::service('entity_field.manager')
    ->getFieldDefinitions($entity_type, $bundle);
  foreach ($field_definitions as $field_name => $field_definition) {
    if ($field_definition
      ->getType() == 'image') {
      $field_config = FieldConfig::loadByName($entity_type, $bundle, $field_name);
      if (isset($field_config)) {
        $image_fields[$field_name] = $field_config;
      }
    }
  }
  return $image_fields;
}

/**
 * Return a list of image replace enabled style => label map.
 *
 * @return array
 *   A key-value list where keys are style names and values are style labels of
 *   image styles having a replace effect configured.
 */
function _image_replace_style_options() {
  $styles = ImageStyle::loadMultiple();
  $result = [];
  foreach ($styles as $style_name => $style) {
    foreach ($style
      ->getEffects() as $effect) {
      if ($effect
        ->getPluginId() == 'image_replace') {
        $result[$style_name] = Html::escape($style
          ->get('label'));
      }
    }
  }
  return $result;
}

Functions

Name	Description
image_replace_entity_presave	Implements hook_field_attach_presave().
image_replace_form_field_config_edit_form_alter	Implements hook_form_FORM_ID_alter() for 'field_config_edit_form'.
image_replace_form_field_config_edit_form_element_validate	Form element validation callback.
image_replace_image_style_presave	Implements hook_ENTITY_TYPE_presave().
_image_replace_image_fields	Collect info for all image field instances on a given entity_type/bundle.
_image_replace_style_options	Return a list of image replace enabled style => label map.