Notification Service
====================

.. list-table::
   :header-rows: 1

   * - Technical name
     - Dependencies
   * - ``notifications``
     - None

Overview
--------

Like the name suggests, the ``notifications`` service allows the rest of the
interface to display notifications (to inform the user of some interesting
relevant facts).

API
---

The ``notifications`` service provides two methods:


* 
  ``create(message: string, options?: Options): number``. This method generates a
  new notification, and returns an ``id`` value.

  Here is a list of the various options:


  * ``title (string)`` : if given, this string will be used as a title
  * ``sticky (boolean)`` : if true, this flag states that the notification should only close
    with an action of the user (not close itself automatically)
  * `type (string)`: can be one of the following: ``danger`` , ``warning`` , ``success`` , ``info``.
    These types will slightly alter the color and the icon that will be used
    to draw the notification
  * ``icon (string)`` : if no type is given, this string describes a css class that
    will be used. It is meant to use a font awesome class. For example, ``fa-cog``
  * ``className (string)`` : describes a css class that will be added to the
    notification. It is useful when one needs to add some special style to a
    notification.
  * ``messageIsHtml (boolean)`` : if true, the message won't be escaped (false by default)

* 
  ``close(id: string)`` : this method will simply close a notification with a specific ``id`` ,
  if it was not already closed.

Example
-------

Here is how one component can simply display a notification:

.. code-block:: js

   class MyComponent extends Component {
       ...
       notifications = useService('notifications');

       ...

       someHandler() {
           this.notifications.create('Look behind you!!!', { sticky: true });
       }
   }

Notes
-----


* whenever the list of notifications is updated, a ``NOTIFICATIONS_CHANGE`` event is
  triggered on the main bus.