.. _extending_notification_service:

#############################
Adding a notification service
#############################

Post Status Notifier has a built-in email notification service. But it is easy to implement custom notification services.

After the built-in services have been loaded, PSN triggers the action ``psn_after_load_services`` which you can use to register your custom notification service.

Let's say you put the logic for your custom service in a class file **MyService.php** located in the Example module's subdirectory lib/Service:

.. code:: jinja

    Example
    └ lib
      └ Service
        └ MyService.php

In the module's bootstrap.php you can load your service like this:

.. code::

    <?php
    public function bootstrap()
    {
        // register a method for the load_services action
        add_action('psn_after_load_services', array($this, 'addNotificationService'));
    }

    /**
     * Adds a new notification service
     *
     * @param Psn_Notification_Manager $notificationManager
     */
    public function addNotificationService(Psn_Notification_Manager $notificationManager)
    {
        // include the service class
        require_once $this->getPathinfo()->getRootLib() . 'Service/MyService.php';
        // add the service to the notification service manager
        $notificationManager->addService(new Psn_Module_Example_Service_MyService($this->_pm));
    }

The callback function for the action ``psn_after_load_services`` expects one parameter, an object of type ``Psn_Notification_Manager``. This is PSN's Notification Manager object. Use it to add your service with the method ``addService``.

**************
Service object
**************

A Post Status Notifier service object must implement the interface ``Psn_Notification_Service_Interface`` to be accepted by the Notification Manager's addService method. Following the interface, the notification service object must implement the method ``execute``. It receives **two parameters**, the **notification rule object** which matched the post status transition and the WordPress **post object** of the post which got changed.

.. code::

    <?php
    public function execute(Psn_Model_Rule $rule, $post)
    {
    }

Now it's up to you to implement your custom notification service.