5 * Controls the visual building blocks a page is constructed with.
8 use Drupal\Component\Utility\Html;
9 use Drupal\Core\Routing\RouteMatchInterface;
11 use Drupal\language\ConfigurableLanguageInterface;
12 use Drupal\system\Entity\Menu;
13 use Drupal\block\Entity\Block;
16 * Implements hook_help().
18 function block_help($route_name, RouteMatchInterface $route_match) {
19 switch ($route_name) {
20 case 'help.page.block':
21 $block_content = \Drupal::moduleHandler()->moduleExists('block_content') ? \Drupal::url('help.page', ['name' => 'block_content']) : '#';
23 $output .= '<h3>' . t('About') . '</h3>';
24 $output .= '<p>' . t('The Block module allows you to place blocks in regions of your installed themes, and configure block settings. For more information, see the <a href=":blocks-documentation">online documentation for the Block module</a>.', [':blocks-documentation' => 'https://www.drupal.org/documentation/modules/block/']) . '</p>';
25 $output .= '<h3>' . t('Uses') . '</h3>';
27 $output .= '<dt>' . t('Placing and moving blocks') . '</dt>';
28 $output .= '<dd>' . t('You can place a new block in a region by selecting <em>Place block</em> on the <a href=":blocks">Block layout page</a>. Once a block is placed, it can be moved to a different region by drag-and-drop or by using the <em>Region</em> drop-down list, and then clicking <em>Save blocks</em>.', [':blocks' => \Drupal::url('block.admin_display')]) . '</dd>';
29 $output .= '<dt>' . t('Toggling between different themes') . '</dt>';
30 $output .= '<dd>' . t('Blocks are placed and configured specifically for each theme. The Block layout page opens with the default theme, but you can toggle to other installed themes.') . '</dd>';
31 $output .= '<dt>' . t('Demonstrating block regions for a theme') . '</dt>';
32 $output .= '<dd>' . t('You can see where the regions are for the current theme by clicking the <em>Demonstrate block regions</em> link on the <a href=":blocks">Block layout page</a>. Regions are specific to each theme.', [':blocks' => \Drupal::url('block.admin_display')]) . '</dd>';
33 $output .= '<dt>' . t('Configuring block settings') . '</dt>';
34 $output .= '<dd>' . t('To change the settings of an individual block click on the <em>Configure</em> link on the <a href=":blocks">Block layout page</a>. The available options vary depending on the module that provides the block. For all blocks you can change the block title and toggle whether to display it.', [':blocks' => Drupal::url('block.admin_display')]) . '</dd>';
35 $output .= '<dt>' . t('Controlling visibility') . '</dt>';
36 $output .= '<dd>' . t('You can control the visibility of a block by restricting it to specific pages, content types, and/or roles by setting the appropriate options under <em>Visibility settings</em> of the block configuration.') . '</dd>';
37 $output .= '<dt>' . t('Adding custom blocks') . '</dt>';
38 $output .= '<dd>' . t('You can add custom blocks, if the <em>Custom Block</em> module is installed. For more information, see the <a href=":blockcontent-help">Custom Block help page</a>.', [':blockcontent-help' => $block_content]) . '</dd>';
42 if ($route_name == 'block.admin_display' || $route_name == 'block.admin_display_theme') {
43 $demo_theme = $route_match->getParameter('theme') ?: \Drupal::config('system.theme')->get('default');
44 $themes = \Drupal::service('theme_handler')->listInfo();
45 $output = '<p>' . t('Block placement is specific to each theme on your site. Changes will not be saved until you click <em>Save blocks</em> at the bottom of the page.') . '</p>';
46 $output .= '<p>' . \Drupal::l(t('Demonstrate block regions (@theme)', ['@theme' => $themes[$demo_theme]->info['name']]), new Url('block.admin_demo', ['theme' => $demo_theme])) . '</p>';
52 * Implements hook_theme().
54 function block_theme() {
57 'render element' => 'elements',
63 * Implements hook_page_top().
65 function block_page_top(array &$page_top) {
66 if (\Drupal::routeMatch()->getRouteName() === 'block.admin_demo') {
67 $theme = \Drupal::theme()->getActiveTheme()->getName();
68 $page_top['backlink'] = [
70 '#title' => t('Exit block region demonstration'),
71 '#options' => ['attributes' => ['class' => ['block-demo-backlink']]],
74 if (\Drupal::config('system.theme')->get('default') == $theme) {
75 $page_top['backlink']['#url'] = Url::fromRoute('block.admin_display');
78 $page_top['backlink']['#url'] = Url::fromRoute('block.admin_display_theme', ['theme' => $theme]);
84 * Initializes blocks for installed themes.
87 * An array of theme names.
89 function block_themes_installed($theme_list) {
90 foreach ($theme_list as $theme) {
91 // Don't initialize themes that are not displayed in the UI.
92 if (\Drupal::service('theme_handler')->hasUi($theme)) {
93 block_theme_initialize($theme);
99 * Assigns an initial, default set of blocks for a theme.
101 * This function is called the first time a new theme is installed. The new
102 * theme gets a copy of the default theme's blocks, with the difference that if
103 * a particular region isn't available in the new theme, the block is assigned
104 * to the new theme's default region.
107 * The name of a theme.
109 function block_theme_initialize($theme) {
110 // Initialize theme's blocks if none already registered.
111 $has_blocks = \Drupal::entityTypeManager()->getStorage('block')->loadByProperties(['theme' => $theme]);
113 $default_theme = \Drupal::config('system.theme')->get('default');
114 // Apply only to new theme's visible regions.
115 $regions = system_region_list($theme, REGIONS_VISIBLE);
116 $default_theme_blocks = \Drupal::entityTypeManager()->getStorage('block')->loadByProperties(['theme' => $default_theme]);
117 foreach ($default_theme_blocks as $default_theme_block_id => $default_theme_block) {
118 if (strpos($default_theme_block_id, $default_theme . '_') === 0) {
119 $id = str_replace($default_theme, $theme, $default_theme_block_id);
122 $id = $theme . '_' . $default_theme_block_id;
124 $block = $default_theme_block->createDuplicateBlock($id, $theme);
125 // If the region isn't supported by the theme, assign the block to the
126 // theme's default region.
127 if (!isset($regions[$block->getRegion()])) {
128 $block->setRegion(system_default_region($theme));
136 * Implements hook_rebuild().
138 function block_rebuild() {
139 foreach (\Drupal::service('theme_handler')->listInfo() as $theme => $data) {
141 $regions = system_region_list($theme);
142 /** @var \Drupal\block\BlockInterface[] $blocks */
143 $blocks = \Drupal::entityTypeManager()->getStorage('block')->loadByProperties(['theme' => $theme]);
144 foreach ($blocks as $block_id => $block) {
145 // Disable blocks in invalid regions.
146 if (!isset($regions[$block->getRegion()])) {
147 if ($block->status()) {
149 ->addWarning(t('The block %info was assigned to the invalid region %region and has been disabled.', [
150 '%info' => $block_id,
151 '%region' => $block->getRegion(),
155 ->setRegion(system_default_region($theme))
165 * Implements hook_theme_suggestions_HOOK().
167 function block_theme_suggestions_block(array $variables) {
170 $suggestions[] = 'block__' . $variables['elements']['#configuration']['provider'];
171 // Hyphens (-) and underscores (_) play a special role in theme suggestions.
172 // Theme suggestions should only contain underscores, because within
173 // drupal_find_theme_templates(), underscores are converted to hyphens to
174 // match template file names, and then converted back to underscores to match
175 // pre-processing and other function names. So if your theme suggestion
176 // contains a hyphen, it will end up as an underscore after this conversion,
177 // and your function names won't be recognized. So, we need to convert
178 // hyphens to underscores in block deltas for the theme suggestions.
180 // We can safely explode on : because we know the Block plugin type manager
181 // enforces that delimiter for all derivatives.
182 $parts = explode(':', $variables['elements']['#plugin_id']);
183 $suggestion = 'block';
184 while ($part = array_shift($parts)) {
185 $suggestions[] = $suggestion .= '__' . strtr($part, '-', '_');
188 if (!empty($variables['elements']['#id'])) {
189 $suggestions[] = 'block__' . $variables['elements']['#id'];
196 * Prepares variables for block templates.
198 * Default template: block.html.twig.
200 * Prepares the values passed to the theme_block function to be passed
201 * into a pluggable template engine. Uses block properties to generate a
202 * series of template file suggestions. If none are found, the default
203 * block.html.twig is used.
205 * Most themes use their own copy of block.html.twig. The default is located
206 * inside "core/modules/block/templates/block.html.twig". Look in there for the
207 * full list of available variables.
209 * @param array $variables
210 * An associative array containing:
211 * - elements: An associative array containing the properties of the element.
212 * Properties used: #block, #configuration, #children, #plugin_id.
214 function template_preprocess_block(&$variables) {
215 $variables['configuration'] = $variables['elements']['#configuration'];
216 $variables['plugin_id'] = $variables['elements']['#plugin_id'];
217 $variables['base_plugin_id'] = $variables['elements']['#base_plugin_id'];
218 $variables['derivative_plugin_id'] = $variables['elements']['#derivative_plugin_id'];
219 $variables['label'] = !empty($variables['configuration']['label_display']) ? $variables['configuration']['label'] : '';
220 $variables['content'] = $variables['elements']['content'];
221 // A block's label is configuration: it is static. Allow dynamic labels to be
222 // set in the render array.
223 if (isset($variables['elements']['content']['#title']) && !empty($variables['configuration']['label_display'])) {
224 $variables['label'] = $variables['elements']['content']['#title'];
227 // Create a valid HTML ID and make sure it is unique.
228 if (!empty($variables['elements']['#id'])) {
229 $variables['attributes']['id'] = Html::getUniqueId('block-' . $variables['elements']['#id']);
232 // Proactively add aria-describedby if possible to improve accessibility.
233 if ($variables['label'] && isset($variables['attributes']['role'])) {
234 $variables['title_attributes']['id'] = Html::getUniqueId($variables['label']);
235 $variables['attributes']['aria-describedby'] = $variables['title_attributes']['id'];
241 * Implements hook_ENTITY_TYPE_delete() for user_role entities.
243 * Removes deleted role from blocks that use it.
245 function block_user_role_delete($role) {
246 foreach (Block::loadMultiple() as $block) {
247 /** @var $block \Drupal\block\BlockInterface */
248 $visibility = $block->getVisibility();
249 if (isset($visibility['user_role']['roles'][$role->id()])) {
250 unset($visibility['user_role']['roles'][$role->id()]);
251 $block->setVisibilityConfig('user_role', $visibility['user_role']);
258 * Implements hook_ENTITY_TYPE_delete() for menu entities.
260 function block_menu_delete(Menu $menu) {
261 if (!$menu->isSyncing()) {
262 foreach (Block::loadMultiple() as $block) {
263 if ($block->getPluginId() == 'system_menu_block:' . $menu->id()) {
271 * Implements hook_ENTITY_TYPE_delete() for 'configurable_language'.
273 * Delete the potential block visibility settings of the deleted language.
275 function block_configurable_language_delete(ConfigurableLanguageInterface $language) {
276 // Remove the block visibility settings for the deleted language.
277 foreach (Block::loadMultiple() as $block) {
278 /** @var $block \Drupal\block\BlockInterface */
279 $visibility = $block->getVisibility();
280 if (isset($visibility['language']['langcodes'][$language->id()])) {
281 unset($visibility['language']['langcodes'][$language->id()]);
282 $block->setVisibilityConfig('language', $visibility['language']);