template_preprocess_book_navigation(&$variables)
Prepares variables for book navigation templates.
Default template: book-navigation.html.twig.
Parameters
array $variables: An associative array containing the following key:
- book_link: An associative array of book link properties. Properties used: bid, link_title, depth, pid, nid.
File
- core/modules/book/book.module, line 388
- Allows users to create and organize related content in an outline.
Code
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 | function template_preprocess_book_navigation(&$variables) { $book_link = $variables['book_link']; // Provide extra variables for themers. Not needed by default. $variables['book_id'] = $book_link['bid']; $variables['book_title'] = $book_link['link_title']; $variables['book_url'] = \Drupal::url('entity.node.canonical', array('node' => $book_link['bid'])); $variables['current_depth'] = $book_link['depth']; $variables['tree'] = ''; /** @var \Drupal\book\BookOutline $book_outline */ $book_outline = \Drupal::service('book.outline'); if ($book_link['nid']) { $variables['tree'] = $book_outline->childrenLinks($book_link); $build = array(); if ($prev = $book_outline->prevLink($book_link)) { $prev_href = \Drupal::url('entity.node.canonical', array('node' => $prev['nid'])); $build['#attached']['html_head_link'][][] = array( 'rel' => 'prev', 'href' => $prev_href, ); $variables['prev_url'] = $prev_href; $variables['prev_title'] = $prev['title']; } /** @var \Drupal\book\BookManagerInterface $book_manager */ $book_manager = \Drupal::service('book.manager'); if ($book_link['pid'] && $parent = $book_manager->loadBookLink($book_link['pid'])) { $parent_href = \Drupal::url('entity.node.canonical', array('node' => $book_link['pid'])); $build['#attached']['html_head_link'][][] = array( 'rel' => 'up', 'href' => $parent_href, ); $variables['parent_url'] = $parent_href; $variables['parent_title'] = $parent['title']; } if ($next = $book_outline->nextLink($book_link)) { $next_href = \Drupal::url('entity.node.canonical', array('node' => $next['nid'])); $build['#attached']['html_head_link'][][] = array( 'rel' => 'next', 'href' => $next_href, ); $variables['next_url'] = $next_href; $variables['next_title'] = $next['title']; } } if (!empty($build)) { drupal_render($build); } $variables['has_links'] = FALSE; // Link variables to filter for values and set state of the flag variable. $links = array('prev_url', 'prev_title', 'parent_url', 'parent_title', 'next_url', 'next_title'); foreach ($links as $link) { if (isset($variables[$link])) { // Flag when there is a value. $variables['has_links'] = TRUE; } else { // Set empty to prevent notices. $variables[$link] = ''; } }} |
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