1{#
2/**
3 * @file
4 * Theme override to navigate books.
5 *
6 * Presented under nodes that are a part of book outlines.
7 *
8 * Available variables:
9 * - tree: The immediate children of the current node rendered as an unordered
10 *   list.
11 * - current_depth: Depth of the current node within the book outline. Provided
12 *   for context.
13 * - prev_url: URL to the previous node.
14 * - prev_title: Title of the previous node.
15 * - parent_url: URL to the parent node.
16 * - parent_title: Title of the parent node. Not printed by default. Provided
17 *   as an option.
18 * - next_url: URL to the next node.
19 * - next_title: Title of the next node.
20 * - has_links: Flags TRUE whenever the previous, parent or next data has a
21 *   value.
22 * - book_id: The book ID of the current outline being viewed. Same as the node
23 *   ID containing the entire outline. Provided for context.
24 * - book_url: The book/node URL of the current outline being viewed. Provided
25 *   as an option. Not used by default.
26 * - book_title: The book/node title of the current outline being viewed.
27 *
28 * @see template_preprocess_book_navigation()
29 */
30#}
31{% if tree or has_links %}
32  <nav role="navigation" aria-labelledby="book-label-{{ book_id }}">
33    {{ tree }}
34    {% if has_links %}
35      <h2>{{ 'Book traversal links for'|t }} {{ book_title }}</h2>
36      <ul>
37      {% if prev_url %}
38        <li>
39          <a href="{{ prev_url }}" rel="prev" title="{{ 'Go to previous page'|t }}"><b>{{ '‹'|t }}</b> {{ prev_title }}</a>
40        </li>
41      {% endif %}
42      {% if parent_url %}
43        <li>
44          <a href="{{ parent_url }}" title="{{ 'Go to parent page'|t }}">{{ 'Up'|t }}</a>
45        </li>
46      {% endif %}
47      {% if next_url %}
48        <li>
49          <a href="{{ next_url }}" rel="next" title="{{ 'Go to next page'|t }}">{{ next_title }} <b>{{ '›'|t }}</b></a>
50        </li>
51      {% endif %}
52    </ul>
53    {% endif %}
54  </nav>
55{% endif %}
56