Add THREAD_USER_IS_READY event

src/mibew/libs/chat.php

@@ -18,6 +18,8 @@
  */
 
 use Mibew\Asset\Generator\UrlGeneratorInterface as AssetUrlGeneratorInterface;
+use Mibew\EventDispatcher\EventDispatcher;
+use Mibew\EventDispatcher\Events;
 use Mibew\Settings;
 use Mibew\Thread;
 use Mibew\Style\ChatStyle;
@@ -717,5 +719,10 @@ function chat_start_for_user(
         );
     }
 
+    // Let plugins know that user is ready to chat.
+    $dispatcher = EventDispatcher::getInstance();
+    $event_args = array('thread' => $thread);
+    $dispatcher->triggerEvent(Events::THREAD_USER_IS_READY, $event_args);
+
     return $thread;
 }

src/mibew/libs/classes/Mibew/EventDispatcher/Events.php

@@ -414,6 +414,18 @@ final class Events
      */
     const THREAD_GET_MESSAGES_ALTER = 'threadGetMessagesAlter';
 
+    /**
+     * User is ready to chat.
+     *
+     * This event is triggered after the thread is created, the user passed
+     * pre-chat survey and all system messages are sent to him. This event is
+     * not triggered if there are no online operators and the chat cannot be
+     * started. An associative array with the following items is passed to the
+     * event handlers:
+     *  - "thread": an instance of {@link \Mibew\Thread}.
+     */
+    const THREAD_USER_IS_READY = 'threadUserIsReady';
+
     /**
      * Threads list is ready to be sent to client.
      *