Registries
==========

Overview
--------

The Odoo web client provides many registries, which allow developers to extend
the web client in a safe and structured way.

Here is a list of all registries:

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

   * - Name
     - Description
   * - ``actions``
     - definition of all available client actions
   * - ``Components``
     - components (class) that will be instantiated at root of web client
   * - ``errorDialogs``
     - dialogs (class) that will be instantiated by the crash manager to handle errors
   * - ``services``
     - definition of all services that will be deployed
   * - `systray <../systray.md#adding-a-systray-item>`_
     - components (class) that will be display in the systray menu (a part of the navbar)
   * - ``views``
     - definition of all available views
   * - `userMenu <user_menu.md>`_
     - definition of all user menu items


Usage
-----

A registry is an owl `EventBus <https://github.com/odoo/owl/blob/master/doc/reference/event_bus.md#-event-bus->`_ with some additional methods (below ``T`` is the type of values to be found in the registry):


* ``add: (key: string, value: T, force: boolean = false) => Registry<T>`` : add an entry ``(key, value)`` to the registry. By default, add
  a key already used results in an error. This can be prevented by using the parameter ``force`` , leading to the replacement of the old entry.
  The ``add`` method returns the registry itself to allow chaining.
* ``get: (key: string) => T`` : returns a value from the registry. An error is thrown in case the key cannot be found in the registry.
* ``contains: (key: string) => boolean`` : allow to check the presence of a key in the registry.
* ``getAll: () => T[]`` : returns the registry values.
* ``getEntries: () => [string, T][]`` : returns the registry entries.
* ``remove: (key: string)`` : remove an entry from the registry.

Each time an item is added (deleted) via ``add`` (resp. ``delete`` ), an event "UPDATE" is triggered with a payload of type

.. code-block:: ts

   interface Payload {
       operation: "add" | "delete";
       key: string;
       value: T;
   }