bibcite_footnotes/bibcite_footnotes.module

<?php

/**
 * @file
 * Contains bibcite_footnotes.module.
 */

use Drupal\Core\Form\FormStateInterface;
use Drupal\Core\Routing\RouteMatchInterface;
use Drupal\Core\Url;
use Drupal\Core\Link;
use Drupal\bibcite_footnotes\CitationTools;

/**_bibcite_foot
 * Implements hook_help().
 */
function bibcite_footnotes_help($route_name, RouteMatchInterface $route_match) {
  switch ($route_name) {
    // Main module help for the bibcite_footnotes module.
    case 'help.page.bibcite_footnotes':
      $output = '';
      $output .= '<h3>' . t('About') . '</h3>';
      $output .= '<p>' . t('Inline footnote links for BibCite References') . '</p>';
      return $output;

    default:
  }
}

/**
 * Implementation of hook_preprocess_footnote_list().
 *
 * Gatehrs all notes and prints out Notes and References as separate lists.
 *
 * @param $variables Theme variables.
 *
 * @throws \Drupal\Component\Plugin\Exception\InvalidPluginDefinitionException
 * @throws \Drupal\Component\Plugin\Exception\PluginNotFoundException
 */
function bibcite_footnotes_preprocess_footnote_list(&$variables) {
  $config = \Drupal::config('filter.format.rich_text_references');//filters.filter_reference_footnotes.settings');
  $footnotes = $variables['footnotes'];

  $notes = [
    '#theme' => 'item_list',
    '#list_type' => 'ul',
    '#title' => $config->get('filters.filter_reference_footnotes.settings.notes_section_label'),
    '#attributes' => ['class' => 'footnotes'],
    '#wrapper_attributes' => ['class' => 'container'],
  ];

  $references= [
    '#theme' => 'item_list',
    '#list_type' => 'ul',
    '#title' => $config->get('filters.filter_reference_footnotes.settings.references_section_label'),
    '#attributes' => ['class' => 'footnotes'],
    '#wrapper_attributes' => ['class' => 'container'],

  ];
  $references['#attached']['library'][] = 'bibcite_footnotes/reference_footnote';
  $dont_show_backlink_text = $config->get('filters.filter_reference_footnotes.settings.reference_dont_show_backlink_text');
  $sort_references_by = $config->get('filters.filter_reference_footnotes.settings.reference_sort_by');
  $citation_tools = new CitationTools();
  foreach ($footnotes as $fn) {
    $item = [
      '#id' => $fn['fn_id'],
      '#wrapper_attributes' => [
        'class' => ['footnote'],
      ],
    ];
    $build = [];
    $reference_entity_id = $fn['reference'];

    $footnote_link_text = ($dont_show_backlink_text && $reference_entity_id) ? '^' : $fn['value'];
    if (!is_array($fn['ref_id'])) {
      $url = Url::fromUserInput('#' . $fn['ref_id'], ['attributes' => ['id' => $fn['fn_id'], 'class' => 'footnote-link']]);
      $link = Link::fromTextAndUrl(($footnote_link_text), $url)->toRenderable();
      $build['footnote-link'] = $link;
    }
    else {
      // Output footnote that has more than one reference to it in the body.
      // The only difference is to insert backlinks to all references.
      // Helper: we need to enumerate a, b, c...
      $abc = str_split("abcdefghijklmnopqrstuvwxyz");
      $i = 0;

      $url = Url::fromUserInput('#' . $fn['ref_id'][0], ['attributes' => ['id' => $fn['fn_id'], 'class' => 'footnote-link']]);
      $build['footnote-link'] = Link::fromTextAndUrl($footnote_link_text, $url)->toRenderable();

      foreach ($fn['ref_id'] as $ref) {
        $url = Url::fromUserInput( '#' . $ref, ['attributes' => ['id' => $fn['fn_id'], 'class' => 'footnote-multi']]);
        $build[] = Link::fromTextAndUrl($abc[$i], $url)->toRenderable();

        $i++;
      }
    }

    if (!empty($fn['text'])) {
      // Handle the case where an endnote contains text and a reference.
      // It will appear in both lists. But the link text for the endnote should
      // always be the title of the note. So make a copy of the biuld arrray
      // and change the link text.
      $note_build = $build + ['#type' => 'markup', '#markup' => ' <span class="endnote-text">' . $fn['text'] . '</span>'];
      $note_build['footnote-link'] = Link::fromTextAndUrl($fn['value'], $url)->toRenderable();
      if (!empty($reference_entity_id)) {
        $citation_build = $citation_tools->getRenderableReference($reference_entity_id);
        $note_build[] = $citation_build;
      }
      $note_item = [] + $item;
      $note_item['#markup'] = render($note_build);

      $notes['#items'][] = $note_item;
    }

    if (!empty($reference_entity_id)) {
      $citation_build = $citation_tools->getRenderableReference($reference_entity_id);

      $build[] = $citation_build;
      $render = render($build);
      $item['#markup'] = $render;
      $item['sort'] = trim(strip_tags(render($citation_build)));
      $references['#items'][] = $item;

    }

  }

  $variables['notes'] = $notes;

  if ($sort_references_by == 'alphabetical') {
    usort($references['#items'], '_bibcite_footnotes_reference_array_cmp');
  }
  $variables['references'] = $references;
}

function _bibcite_footnotes_reference_array_cmp($a, $b) {
  $a1 = (!empty($a['sort']) ? strtolower($a['sort']) : '');
  $b1 = (!empty($b['sort']) ? strtolower($b['sort']) : '');
  return strcmp($a1, $b1);
}

function bibcite_footnotes_preprocess_footnote_link(&$variables) {
//  $variables['fn']['fn']['#type'] = 'markeup';
//  $variables['fn']['fn']['#markup'] = '<h2>Hello!</h2>';
  $fn = $variables['fn']['fn'];
  // TODO: Make a more formal way to denote inline citations.

  $class = 'see-footnote';
  // Generate the hover text
  $citation_tools = new CitationTools();
  $citation_entity_id = $fn['reference'];
  $citation_data = $citation_tools->getRenderableReference($citation_entity_id);

  // Citation contains a page reference, so construct parenthetical footnote.
  if (!empty($fn['page'])) {
    $fn['value'] = "({$fn['value']}, {$fn['page']})";
    $citation_data['#data']['page'] = $fn['page'];
    $class .= '-inline';
  }

  $title = trim(strip_tags(render($citation_data)));
  $url = Url::fromUserInput('#' . $fn['fn_id'], ['attributes' => ['id' => $fn['ref_id'], 'class' => $class, 'title' => $title]]);
  

  $link = Link::fromTextAndUrl($fn['value'], $url)->toRenderable();
  $variables['fn']['fn'][] = $link;
}

function bibcite_footnotes_theme_registry_alter(&$theme_registry) {
  unset($theme_registry['footnote_list']['function']);
  $theme_registry['footnote_list']['path'] = drupal_get_path('module', 'bibcite_footnotes') . '/templates';
  $theme_registry['footnote_list']['template'] = 'footnote-list';
  $theme_registry['footnote_list']['variables']['notes'] = [];
  $theme_registry['footnote_list']['variables']['references'] = [];
  $theme_registry['footnote_list']['variables']['footnotes'] = [];

  unset($theme_registry['footnote_link']['function']);
  $theme_registry['footnote_link']['path'] = drupal_get_path('module', 'bibcite_footnotes') . '/templates';
  $theme_registry['footnote_link']['template'] = 'footnote-link';
}