block.module

<?php


/**
 * @file
 */
use Drupal\Component\Utility\Html;
use Drupal\Core\Installer\InstallerKernel;

/**
 * Initializes blocks for installed themes.
 *
 * @param $theme_list
 *   An array of theme names.
 *
 * @see block_modules_installed()
 */
function block_themes_installed($theme_list) {
    // Disable this functionality prior to install profile installation because
    // block configuration is often optional or provided by the install profile
    // itself. block_theme_initialize() will be called when the install profile is
    // installed.
    if (InstallerKernel::installationAttempted() && \Drupal::config('core.extension')->get('module.' . \Drupal::installProfile()) === NULL) {
        return;
    }
    foreach ($theme_list as $theme) {
        // Don't initialize themes that are not displayed in the UI.
        if (\Drupal::service('theme_handler')->hasUi($theme)) {
            block_theme_initialize($theme);
        }
    }
}

/**
 * Assigns an initial, default set of blocks for a theme.
 *
 * This function is called the first time a new theme is installed. The new
 * theme gets a copy of the default theme's blocks, with the difference that if
 * a particular region isn't available in the new theme, the block is assigned
 * to the new theme's default region.
 *
 * @param $theme
 *   The name of a theme.
 */
function block_theme_initialize($theme) {
    // Initialize theme's blocks if none already registered.
    $has_blocks = \Drupal::entityTypeManager()->getStorage('block')
        ->loadByProperties([
        'theme' => $theme,
    ]);
    if (!$has_blocks) {
        $default_theme = \Drupal::config('system.theme')->get('default');
        // Apply only to new theme's visible regions.
        $regions = system_region_list($theme, REGIONS_VISIBLE);
        $default_theme_blocks = \Drupal::entityTypeManager()->getStorage('block')
            ->loadByProperties([
            'theme' => $default_theme,
        ]);
        foreach ($default_theme_blocks as $default_theme_block_id => $default_theme_block) {
            if (str_starts_with($default_theme_block_id, $default_theme . '_')) {
                $id = str_replace($default_theme . '_', '', $default_theme_block_id);
            }
            else {
                $id = $default_theme_block_id;
            }
            $id = \Drupal::service('block.repository')->getUniqueMachineName($id, $theme);
            $block = $default_theme_block->createDuplicateBlock($id, $theme);
            // If the region isn't supported by the theme, assign the block to the
            // theme's default region.
            if (!isset($regions[$block->getRegion()])) {
                $block->setRegion(system_default_region($theme));
            }
            $block->save();
        }
    }
}

/**
 * Implements hook_theme_suggestions_HOOK().
 */
function block_theme_suggestions_block(array $variables) {
    $suggestions = [];
    $suggestions[] = 'block__' . $variables['elements']['#configuration']['provider'];
    // Hyphens (-) and underscores (_) play a special role in theme suggestions.
    // Theme suggestions should only contain underscores, because within
    // drupal_find_theme_templates(), underscores are converted to hyphens to
    // match template file names, and then converted back to underscores to match
    // pre-processing and other function names. So if your theme suggestion
    // contains a hyphen, it will end up as an underscore after this conversion,
    // and your function names won't be recognized. So, we need to convert
    // hyphens to underscores in block deltas for the theme suggestions.
    // We can safely explode on : because we know the Block plugin type manager
    // enforces that delimiter for all derivatives.
    $parts = explode(':', $variables['elements']['#plugin_id']);
    $suggestion = 'block';
    while ($part = array_shift($parts)) {
        $suggestions[] = $suggestion .= '__' . strtr($part, '-', '_');
    }
    if (!empty($variables['elements']['#id'])) {
        $suggestions[] = 'block__' . $variables['elements']['#id'];
    }
    return $suggestions;
}

/**
 * Prepares variables for block templates.
 *
 * Default template: block.html.twig.
 *
 * Prepares the values passed to the theme_block function to be passed
 * into a pluggable template engine. Uses block properties to generate a
 * series of template file suggestions. If none are found, the default
 * block.html.twig is used.
 *
 * Most themes use their own copy of block.html.twig. The default is located
 * inside "core/modules/block/templates/block.html.twig". Look in there for the
 * full list of available variables.
 *
 * @param array $variables
 *   An associative array containing:
 *   - elements: An associative array containing the properties of the element.
 *     Properties used: #block, #configuration, #children, #plugin_id.
 */
function template_preprocess_block(&$variables) : void {
    $variables['configuration'] = $variables['elements']['#configuration'];
    $variables['plugin_id'] = $variables['elements']['#plugin_id'];
    $variables['base_plugin_id'] = $variables['elements']['#base_plugin_id'];
    $variables['derivative_plugin_id'] = $variables['elements']['#derivative_plugin_id'];
    $variables['in_preview'] = $variables['elements']['#in_preview'] ?? FALSE;
    $variables['label'] = !empty($variables['configuration']['label_display']) ? $variables['configuration']['label'] : '';
    $variables['content'] = $variables['elements']['content'];
    // A block's label is configuration: it is static. Allow dynamic labels to be
    // set in the render array.
    if (isset($variables['elements']['content']['#title']) && !empty($variables['configuration']['label_display'])) {
        $variables['label'] = $variables['elements']['content']['#title'];
    }
    // Create a valid HTML ID and make sure it is unique.
    if (!empty($variables['elements']['#id'])) {
        $variables['attributes']['id'] = Html::getUniqueId('block-' . $variables['elements']['#id']);
    }
    // Proactively add aria-describedby if possible to improve accessibility.
    if ($variables['label'] && isset($variables['attributes']['role'])) {
        $variables['title_attributes']['id'] = Html::getUniqueId($variables['label']);
        $variables['attributes']['aria-describedby'] = $variables['title_attributes']['id'];
    }
}