edlp_d8/sites/all/modules/figli/edlp_corpus/edlp_corpus.module

<?php
# @Author: Bachir Soussi Chiadmi <bach>
# @Date:   13-12-2017
# @Email:  bachir@figureslibres.io
# @Filename: edlp_corpus.routing.yml
# @Last modified by:   bach
# @Last modified time: 20-12-2017
# @License: GPL-V3


/**
 * Implements hook_theme().
 */
function edlp_corpus_theme($existing, $type, $theme, $path) {
  // @see https://www.drupal.org/docs/8/theming/twig/create-custom-twig-templates-from-custom-module

  return array(
    'blockentrees' => array(
      // 'render element' => '',
      'file' => 'blockentrees.inc',
      'variables' => array(
        'entrees_items' => array(),
      ),
    ),
  );
}


/**
* hook_entity_extra_field_info()
*
*/
function edlp_corpus_entity_extra_field_info(){
  $extra = [];
  $extra['taxonomy_term']['entrees']['display']['index'] = [
    'label' => t('Index'),
    'description' => 'Display index of all documents tagued with the term',
    'weight' => 99,
    // 'visible' => FALSE,
  ];
  return $extra;
}


/**
 * Implements hook_ENTITY_TYPE_view().
 * @see https://www.amazeelabs.com/en/render-menu-tree-custom-code-drupal-8
 */
function edlp_corpus_taxonomy_term_view(array &$build, \Drupal\Core\Entity\EntityInterface $entity, \Drupal\Core\Entity\Display\EntityViewDisplayInterface $display, $view_mode) {
  $index_display_settings = $display->getComponent('index');
  if (!empty($index_display_settings)) {
    // dpm($entity);
    // dpm($entity->id());
    $view_builder = \Drupal::entityTypeManager()->getViewBuilder('node');

    $query = \Drupal::entityQuery('node')
      ->condition('status', 1)
      ->condition('type', 'enregistrement')
      ->condition('field_entrees', $entity->id());

    $documents_nids = $query->execute();
    $documents = entity_load_multiple('node', $documents_nids);

    $documents_list = array (
      '#theme' => 'item_list',
      '#items' => [],
    );
    foreach($documents as $doc){
      $documents_list['#items'][] = $view_builder->view($doc, 'index');
    }

    // And the last step is to actually build the tree.
    $build['index'] = array(
      '#type'=>"container",
      '#attributes'=>array(
        'class'=>'index'
      ),
      'label'=>array(
        '#type' => 'container',
        "#markup"=> t("Index"),
        '#attributes'=>array(
          'class'=>'field__label'
        ),
      ),
      'documents'=> $documents_list
    );
  }
}


/**
 * Implements hook_page_attachments().
 * @param array $attachments
 */
function edlp_corpus_page_attachments(array &$attachments) {

  // css class
  // :root{
  //  --e-col-130:#4B8F7E;
  // }

  // javascript list
  // drupalSettings edlp_corpus{
  //  "e_col_130": "rgb(75, 143, 126)",
  // }


  // get all entries
  $query = \Drupal::entityQuery('taxonomy_term')
    ->condition('vid', 'entrees');

  $tids = $query->execute();
  $terms = entity_load_multiple('taxonomy_term', $tids);

  $js_list = [];
  $css_str = ":root{\n";
  foreach ($terms as $term) {
    $tid = $term->id();
    // get the color value
    $color = $term->get('field_color')->color;
    // build colors list
    $css_str .= "\t".'--e-col-'.$tid.':'.$color.";\n";
    $js_list['e_col_'.$tid] = $color;
  }
  $css_str .= '}';

  // attache css
  // we should find a better way
  // https://www.drupal.org/docs/8/creating-custom-modules/adding-stylesheets-css-and-javascript-js-to-a-drupal-8-module
  $attachments['#attached']['html_head'][] = [
    [
      '#type' => 'html_tag',
      '#tag' => 'style',
      '#value' => $css_str,
    ],
    // A key, to make it possible to recognize this HTML  element when altering.
    'edlp_colors',
  ];

  $attachments['#attached']['drupalSettings']['edlp_corpus']['colors'] = $js_list;

}