rt_notifications.module

<?php

/**
 * @file
 * Contains rt_notifications.module.
 */

use Drupal\Core\Form\FormStateInterface;
use Drupal\Core\Entity\EntityInterface;
use Drupal\Core\Cache\CacheBackendInterface;
use Drupal\Core\Cache\Cache;
use Drupal\Core\Block\BlockPluginInterface;

/**
 * Action constants
 */
const RTN_ACTION_NODE_CREATE = 'node_create';
const RTN_ACTION_NODE_UPDATE = 'node_update';
const RTN_ACTION_NODE_DELETE = 'node_delete';

/**
 * Implements hook_requirements().
 */
function rt_notifications_requirements($phase) {
  $requirements = [];

  $websocket_server_config = Drupal::config('rtn.websocket');
  $host = $websocket_server_config->get('host');
  $port = $websocket_server_config->get('port');
  $connection_is_configured = ($host && $port) ? TRUE : FALSE;

  // Check if server connection is set:
  $requirements['Real-Time Notifications'] = [
    'title' => t('Real-Time Notifications server connection'),
    'value' => $connection_is_configured ? "$host:$port" : t('Not configured!'),
  ];
  if (!$connection_is_configured) {
    $requirements['Real-Time Notifications']['severity'] = REQUIREMENT_ERROR;
    $requirements['Real-Time Notifications']['description'] = t('Missing <a href="/admin/config/system/realtime-notifications">server configuration</a>!');
  }

  return $requirements;
}

/**
 * Implements hook_form_FORM_ID_alter().
 */
function rt_notifications_form_user_form_alter(&$form, FormStateInterface $form_state) {
  $form['field_rtn_select_users']['#states'] = [
    'visible' => array(
      ':input[name="field_rtn_user_selection_mode"]' => array('value' => 'uid'),
    ),
  ];

  // Remove own uid and anonymous user from the list.
  $build_info = $form_state->getBuildInfo();
  /** @var Drupal\user\ProfileForm $object */
  $object = $build_info['callback_object'];
  $form_user_id = $object->getEntity()->id();
  $current_uid = \Drupal::currentuser()->id();
  $user_ids = &$form['field_rtn_select_users']['widget']['#options'];

  // If creating a new user or editing someone else's profile.
  if (!$form_user_id || $form_user_id != $current_uid) {
    unset($user_ids[$form_user_id], $user_ids[0]);
  }
  else {
    unset($user_ids[$current_uid], $user_ids[0]);
  }

  $form['field_rtn_user_settings'] = [
    '#type' => 'details',
    '#title' => t('Real-Time Notifications'),
    '#open' => TRUE,
    '#weight' => 20,
  ];

  foreach (['field_rtn_actions', 'field_rtn_select_users', 'field_rtn_user_selection_mode'] as $field) {
    if (isset($form[$field])) {
      $form['field_rtn_user_settings'][$field] = $form[$field];
      unset($form[$field]);
    }
  }
}

/**
 * Get list of subscribers (user IDs).
 *
 * @param $uid
 *  User ID.
 *
 * @param $action
 *  Action machine name.
 *
 * @return array
 */
function rt_notifications_get_subscribers($uid, $action) {
  $cid = "rt_notifications_subscribers:$action:$uid";
  $tags = ['rt_notifications_subscribers'];
  $cache_backend = \Drupal::cache();
  $db = \Drupal::database();

  if ($cache = $cache_backend->get($cid)) {
    $subscribers = $cache->data;
  }
  else {
    // Get all explicitly subscribed users.
    $query = $db->select('user__field_rtn_actions', 'rtna');
    $query->join('user__field_rtn_select_users', 'rtnsu', 'rtna.entity_id = rtnsu.entity_id');
    $uid_subscribers = $query->fields('rtnsu', ['entity_id'])
      ->condition('rtna.field_rtn_actions_value', $action)
      ->condition('rtnsu.field_rtn_select_users_target_id', $uid)
      ->execute()->fetchCol();

    // Get users subscribed to "All".
    $query = $db->select('user__field_rtn_user_selection_mode', 'rtnusm');
    $query->join('user__field_rtn_actions', 'rtna', 'rtnusm.entity_id = rtna.entity_id');

    $all_subscribers = $query->fields('rtnusm', ['entity_id'])
      ->condition('rtnusm.field_rtn_user_selection_mode_value', 'all')
      ->condition('rtna.field_rtn_actions_value', $action)
      ->execute()->fetchCol();

    $subscribers = array_unique(array_merge($uid_subscribers, $all_subscribers));
    sort($subscribers);

    $cache_backend->set($cid, $subscribers, CacheBackendInterface::CACHE_PERMANENT, $tags);
  }

  return $subscribers;
}

/**
 * Implements hook_ENTITY_TYPE_insert()) for users.
 */
function rt_notifications_user_insert(EntityInterface $entity) {
  Cache::invalidateTags(['rt_notifications_subscribers']);
}

/**
 * Implements hook_ENTITY_TYPE_update() for users.
 */
function rt_notifications_user_update(EntityInterface $entity) {
  Cache::invalidateTags(['rt_notifications_subscribers']);
}

/**
 * Implements hook_ENTITY_TYPE_delete()) for users.
 */
function rt_notifications_user_delete(EntityInterface $entity) {
  Cache::invalidateTags(['rt_notifications_subscribers']);
}

/**
 * Implements hook_ENTITY_TYPE_insert().
 */
function rt_notifications_node_insert(EntityInterface $entity) {
  _send_message_to_subscribers($entity, RTN_ACTION_NODE_CREATE);
}

/**
 * Implements hook_ENTITY_TYPE_update().
 */
function rt_notifications_node_update(EntityInterface $entity) {
  _send_message_to_subscribers($entity, RTN_ACTION_NODE_UPDATE);
}

/**
 * Implements hook_ENTITY_TYPE_delete().
 */
function rt_notifications_node_delete(EntityInterface $entity) {
  _send_message_to_subscribers($entity, RTN_ACTION_NODE_DELETE);
}

/**
 * Implements hook_theme().
 */
function rt_notifications_theme($existing, $type, $theme, $path) {
  return [
    'rt_notifications_block' => [
      'variables' => [
        'notifications' => [],
        'count' => 0,
      ],
    ],
  ];
}

/**
 * Implements hook_block_view_BASE_ID_alter().
 */
function rt_notifications_block_view_rt_notifications_block_alter(array &$build, BlockPluginInterface $block) {
  $build['#contextual_links'] = [];
}

/**
 * Helper function for sending message via WebSocket.
 *
 * @param \Drupal\Core\Entity\EntityInterface $entity
 * @param $action
 */
function _send_message_to_subscribers(EntityInterface $entity, $action) {
  $webSocketConnector = \Drupal::service('rtn.websocket_client');
  $webSocketConnector->connect();
  $client = $webSocketConnector->getClient();
  $action_str = str_replace('node_', '', $action) . 'd';

  // Send message to all users which are subscribed on logged-in user and this action.
  if ($client) {
    $entity_title = $entity->get('title')->value;
    $current_user_id = \Drupal::currentUser()->id();
    $current_user_name = \Drupal::currentUser()->getDisplayName();
    $subscribed_users = rt_notifications_get_subscribers($current_user_id, $action);

    $text = "The user %current_user_name has %action_str the node %entity_title";
    $variables = [
      '%current_user_name' => $current_user_name,
      '%action_str' => $action_str,
      '%entity_title' => $entity_title,
    ];

    $webSocketConnector->sendMessage($subscribed_users, $text, $variables);
    $webSocketConnector->disconnect();
  }
}