function BookNavigationBlock::build

File

core/modules/book/src/Plugin/Block/BookNavigationBlock.php, line 123

Class

BookNavigationBlock

Provides a 'Book navigation' block.

Namespace

Code

public function build() {
    $current_bid = 0;
    if ($node = $this->requestStack
        ->getCurrentRequest()
        ->get('node')) {
        $current_bid = empty($node->book['bid']) ? 0 : $node->book['bid'];
    }
    if ($this->configuration['block_mode'] == 'all pages') {
        $book_menus = [];
        $pseudo_tree = [
            0 => [
                'below' => FALSE,
            ],
        ];
        foreach ($this->bookManager
            ->getAllBooks() as $book_id => $book) {
            if ($book['bid'] == $current_bid) {
                // If the current page is a node associated with a book, the menu
                // needs to be retrieved.
                $data = $this->bookManager
                    ->bookTreeAllData($node->book['bid'], $node->book);
                $book_menus[$book_id] = $this->bookManager
                    ->bookTreeOutput($data);
            }
            else {
                // Since we know we will only display a link to the top node, there
                // is no reason to run an additional menu tree query for each book.
                $book['in_active_trail'] = FALSE;
                // Check whether user can access the book link.
                $book_node = $this->nodeStorage
                    ->load($book['nid']);
                $book['access'] = $book_node->access('view');
                $pseudo_tree[0]['link'] = $book;
                $book_menus[$book_id] = $this->bookManager
                    ->bookTreeOutput($pseudo_tree);
            }
            $book_menus[$book_id] += [
                '#book_title' => $book['title'],
            ];
        }
        if ($book_menus) {
            return [
                '#theme' => 'book_all_books_block',
            ] + $book_menus;
        }
    }
    elseif ($current_bid) {
        // Only display this block when the user is browsing a book and do
        // not show unpublished books.
        $nid = \Drupal::entityQuery('node')->condition('nid', $node->book['bid'], '=')
            ->condition('status', NodeInterface::PUBLISHED)
            ->execute();
        // Only show the block if the user has view access for the top-level node.
        if ($nid) {
            $tree = $this->bookManager
                ->bookTreeAllData($node->book['bid'], $node->book);
            // There should only be one element at the top level.
            $data = array_shift($tree);
            $below = $this->bookManager
                ->bookTreeOutput($data['below']);
            if (!empty($below)) {
                return $below;
            }
        }
    }
    return [];
}