flat_comments.module

<?php

/**
 * @file
 * Contains flat_comments.module.
 */
use Drupal\comment\CommentInterface;
use Drupal\Core\Form\FormStateInterface;
use Drupal\Core\Routing\RouteMatchInterface;

/**
 * Implements hook_help().
 */
function flat_comments_help($route_name, RouteMatchInterface $route_match) {
  $output = '';
  switch ($route_name) {
    // Main module help for the flat_comments module.
    case 'help.page.flat_comments':
      $output = '';
      $output .= '<h3>' . t('About') . '</h3>';
      $output .= '<p>' . t('Make all comments replies to the main post, regardless of the reply link used.') . '</p>';
      $output;

    default:
  }
  return $output;
}

/**
 * Implements hook_form_alter().
 */
function flat_comments_form_field_config_edit_form_alter(
  &$form,
  FormStateInterface $form_state,
  $form_id) {
  /** @var Drupal\field\Entity\FieldConfig $field */
  $field = $form_state->getFormObject()->getEntity();

  // This only applies for comment fields.
  if ($field->getType() != 'comment') {
    return;
  }
  $form['actions']['submit']['#submit'][] = 'flat_comments_save';

  // Add note about flat_comments to comment display description.
  $form['settings']['default_mode']['#description'] .= t(' <strong>flat_comments enabled:</strong> Leave this box unchecked to force replies to be to the main post instead of other comments.');

  // Add option to remove reply link from comments.
  $form['settings']['remove_reply_link'] = [
    '#type' => 'checkbox',
    '#title' => t('Do not show a reply link on comments'),
    '#default_value' => $field->getThirdPartySetting('flat_comments', 'remove_reply_link', FALSE),
  ];
}

function flat_comments_save(array &$form, FormStateInterface $form_state) {
  /** @var Drupal\field\Entity\FieldConfig $field */
  $field = $form_state->getFormObject()->getEntity();
  $values = $form_state->getValues();

  $field->setThirdPartySetting('flat_comments', 'remove_reply_link', $values['settings']['remove_reply_link']);
  $field->save();
}

/**
 * Implementation of hook_comment_presave().
 */
function flat_comments_comment_presave(CommentInterface $comment) {
  $entity = \Drupal::entityManager()
    ->getStorage($comment->getCommentedEntityTypeId())
    ->load($comment->getCommentedEntityId());

  $field_definition = \Drupal::entityManager()
    ->getFieldDefinitions($entity->getEntityTypeId(), $entity->bundle());
  $field_definition = $field_definition[$comment->getFieldName()];

  // Only affect new comments and comments set to be displayed flat.
  if (!$comment->id() && $field_definition->getSetting('default_mode') === 0) {
    // Set parent id to NULL to prevent threads.
    $comment->get('pid')->setValue(NULL);
  }
}

/**
 * Implements hook_comments_links_alter().
 */
function flat_comments_comment_links_alter(
  array &$links,
  CommentInterface $entity,
  array &$context) {

  // If there is not a "reply" link, no need to continue.
  if (!isset($links['comment']['#links']['comment-reply'])) {
    return;
  }

  $comment = $entity;
  $entity = \Drupal::entityManager()
    ->getStorage($comment->getCommentedEntityTypeId())
    ->load($comment->getCommentedEntityId());

  $field_definition = \Drupal::entityManager()
    ->getFieldDefinitions($entity->getEntityTypeId(), $entity->bundle());
  $field_definition = $field_definition[$comment->getFieldName()];

  if($field_definition->getThirdPartySetting('flat_comments', 'remove_reply_link', FALSE)) {
    unset($links['comment']['#links']['comment-reply']);
  }
}