D8 comments

$:/data/disk/o1/static/z-d8-themes/orange# ls
css/  js/  orange.info.yml  orange.libraries.yml  orange.theme  templates/
$:/data/disk/o1/static/z-d8-themes/orange# cat orange.info.yml
name: orange
type: theme
description: This is a sub theme of Bartik
core: 8.x
# Defines the base theme
base theme: bartik
# Defines libraries group in which we can add css/js.
libraries:
  - orange/global-styling

$:/data/disk/o1/static/z-d8-themes/orange# cat orange.theme
<?php
/**
 * Implements template_preprocess_page.
 */
function orange_preprocess_comment(&$variables) {

  $comment = $variables['comment'];
  $owner = $comment->getOwner();
  $roles = $owner->getRoles();

  // Let's pop the roles array to only
  // get the last (highest) role of all.
  $role = array_pop($roles);

  $variables['attributes']['class'][] = 'author-' . $role;
}

function orange_preprocess_page(&$variables) {
  if ($variables['is_front']) {
    $variables['#attached']['library'][] = 'orange/test';
  }
}
$:/data/disk/o1/static/z-d8-themes/orange# cd templates
$:/data/disk/o1/static/z-d8-themes/orange/templates# ls
comment.html.twig
$:/data/disk/o1/static/z-d8-themes/orange/templates# cat comment.html.twig
{#
/**
 * @file
 * Bartik's theme implementation for comments.
 *
 * Available variables:
 * - author: Comment author. Can be a link or plain text.
 * - content: The content-related items for the comment display. Use
 *   {{ content }} to print them all, or print a subset such as
 *   {{ content.field_example }}. Use the following code to temporarily suppress
 *   the printing of a given child element:
 *   @code
 *   {{ content|without('field_example') }}
 *   @endcode
 * - created: Formatted date and time for when the comment was created.
 *   Preprocess functions can reformat it by calling format_date() with the
 *   desired parameters on the 'comment.created' variable.
 * - changed: Formatted date and time for when the comment was last changed.
 *   Preprocess functions can reformat it by calling format_date() with the
 *   desired parameters on the 'comment.changed' variable.
 * - permalink: Comment permalink.
 * - submitted: Submission information created from author and created
 *   during template_preprocess_comment().
 * - user_picture: The comment author's profile picture.
 * - status: Comment status. Possible values are:
 *   unpublished, published, or preview.
 * - title: Comment title, linked to the comment.
 * - attributes: HTML attributes for the containing element.
 *   The attributes.class may contain one or more of the following classes:
 *   - comment: The current template type; e.g., 'theming hook'.
 *   - by-anonymous: Comment by an unregistered user.
 *   - by-{entity-type}-author: Comment by the author of the parent entity,
 *     eg. by-node-author.
 *   - preview: When previewing a new or edited comment.
 *   The following applies only to viewers who are registered users:
 *   - unpublished: An unpublished comment visible only to administrators.
 * - title_prefix: Additional output populated by modules, intended to be
 *   displayed in front of the main title tag that appears in the template.
 * - title_suffix: Additional output populated by modules, intended to be
 *   displayed after the main title tag that appears in the template.
 * - title_attributes: Same as attributes, except applied to the main title
 *   tag that appears in the template.
 * - content_attributes: List of classes for the styling of the comment content.
 * - threaded: A flag indicating whether the comments are threaded or not.
 *
 * These variables are provided to give context about the parent comment (if
 * any):
 * - comment_parent: Full parent comment entity (if any).
 * - parent_author: Equivalent to author for the parent comment.
 * - parent_created: Equivalent to created for the parent comment.
 * - parent_changed: Equivalent to changed for the parent comment.
 * - parent_title: Equivalent to title for the parent comment.
 * - parent_permalink: Equivalent to permalink for the parent comment.
 * - parent: A text string of parent comment submission information created from
 *   'parent_author' and 'parent_created' during template_preprocess_comment().
 *   This information is presented to help screen readers follow lengthy
 *   discussion threads. You can hide this from sighted users using the class
 *   visually-hidden.
 *
 * These two variables are provided for context:
 * - comment: Full comment object.
 * - entity: Entity the comments are attached to.
 *
 * @see template_preprocess_comment()
 */
#}
{%
  set classes = [
    'comment',
    'js-comment',
    status != 'published' ? 'comment--' ~ status,
    comment.owner.anonymous ? 'by-anonymous',
    author_id and author_id == commented_entity.getOwnerId() ? 'by-' ~ commented_entity.getEntityTypeId() ~ '-author',
    'clearfix',
  ]
%}
<article role="article"{{ attributes.addClass(classes)|without('role') }}>
  {#
    Hide the "new" indicator by default, let a piece of JavaScript ask the
    server which comments are new for the user. Rendering the final "new"
    indicator here would break the render cache.
  #}
  <span class="hidden" data-comment-timestamp="{{ new_indicator_timestamp }}"></span>

  <footer class="comment__meta">
    {{ user_picture }}
    <p class="comment__author">{{ author }}</p>
    <p class="comment__time">{{ created }}</p>
    <p class="comment__permalink">{{ permalink }}</p>
    {#
      Indicate the semantic relationship between parent and child comments
      for accessibility. The list is difficult to navigate in a screen
      reader without this information.
    #}
    {% if parent %}
      <p class="visually-hidden">{{ parent }}</p>
    {% endif %}
  </footer>

  <div{{ content_attributes.addClass('comment__content') }}>
    {% if title %}
      {{ title_prefix }}
      <h3{{ title_attributes }}>{{ title }}</h3>
      {{ title_suffix }}
    {% endif %}
    {{ content }}
  </div>
</article>
$:/data/disk/o1/static/z-d8-themes/orange/templates#