Extending Modoboa ***************** Introduction ============ Modoboa offers a plugin API to expand its capabilities. The current implementation provides the following possibilities: * Expand navigation by adding entry points to your plugin inside the GUI * Access and modify administrative objects (domains, mailboxes, etc.) * Register callback actions for specific events Plugins are nothing more than Django applications with an extra file called ``main.py``. This file contains a complete description of the plugin: * Admin and user parameters * Registered events * Custom menu entries The communication between both applications is provided by events. Modoboa offers some kind of hooks to let plugin add custom actions. The following subsections describe plugin architecture and explain how you can create your own plugin. Adding a custom plugin ====================== All Modoboa plugins must be located inside the ``extensions`` directory. To create a new plugin, execute the following steps: * Run ``python manage.py startapp`` to get some basefiles for your plugin, * Move the resulting directory inside the ``extensions`` one, * Create a file called ``main.py`` inside your plugin's directory. The last file you created (ie. ``main.py``) must follow a specific structure in order to be interpreted by Modoboa. The following functions are mandatory:: def init(): """This function is called when Modoboa loads available and activated plugins. Declare parameters and register events here. """ pass def destroy(): """This function is called when a plugin is disabled from the interface. Unregister parameters and events here. """ pass def infos(): """This function is used to populate the plugins list available in the administration panel. It must return a dictionnary containing at least three keys : "name", "version", "description" """ return { "name" : "Example plugin", "version" : "1.0", "description" : "Example description" } def urls(prefix): """This function is used to update the global urls table. It must return a sequence that corresponds to those used inside the main ``urls.py`` file. (ie. a classical Django construction) :param prefix: the global url prefix (the part after the hostname) """ return (r'^%sexample/' % prefix, include('modoboa.extensions.example.urls')) Once you have filled ``main.py``, simply add your plugin's name to the ``INSTALLED_APPS`` variable located inside ``settings.py``. (use the same format as other plugins). Eventually, run ``python manage.py syncdb`` if your plugin provides custom tables. Events ====== Playing with events ------------------- Modoboa provides a simple API to interact with events. It understands two kinds of events: * Those that return a value, * Those that return nothing. Listening to a specific event is achieved as follow:: from modoboa.lib import events events.register(event, callback) ``event`` is the event's name you want to listen to, ``callback`` is the function that will be called when this event is raised. Its prototype must be as follow:: def callback(*args, **kwargs): pass It is very generic, it allows events to provide arguments if needed. You can also stop listening to an event like this:: events.unregister(event, callback) The parameters are the same as those used with ``register``. Read further to get a complete list and description of the available events. UserLogin --------- Raised when a user logs in. This event provides a ``request`` argument that corresponds to the ``Request`` object used inside the associated view function. UserLogout __________ Raised when a user logs out. This event provides a ``request`` argument that corresponds to the ``Request`` object used inside the associated view function. .. _usermenudisplay: UserMenuDisplay --------------- Raised when a user menu is about to be displayed. It provides a ``target`` argument that indicates which menu is being displayed. Possible values are: * ``uprefs_menu`` : corresponds to the menu bar available inside the *User preferences* page * ``top_menu`` : corresponds to the top blue bar All callbacks that listen to this event must return a list of dictionnaries (corresponding to menu entries). Each dictionnary must contain at least the following keys:: {"name" : "a_name_without_spaces", "label" : _("The menu label"), "url" : reverse("your_view"), # can be set to "" "img" : static_url("your_pic")} # can be set to "" AdminMenuDisplay ---------------- Raised when an admin menu is about to be displayed. It provides a ``target`` argument that indicates which menu is being displayed. Possible values are: * ``admin_menu_box`` : corresponds to the menu bar available inside administration pages * ``top_menu`` : corresponds to the *Admin* dropdown menu located inside the top blue bar See :ref:`usermenudisplay` for a description of what callbacks that listen to this event must return. CreateDomain ------------ Raised when a new domain is created. The new domain object is available inside the ``dom`` argument. DeleteDomain ------------ Raised when an existing domain is about to be deleted. The domain object is available inside the ``dom`` argument. CreateMailbox ------------- Raised when a new mailbox is created. The new mailbox object is available inside the ``mbox`` argument. DeleteMailbox ------------- Raised when an existing mailbox is about to be deleted. The mailbox object is available inside the ``mbox`` argument. ModifyMailbox ------------- Raised when an existing mailbox is modified. The old mailbox and the new mailbox objects are respectively available inside the ``oldmbox`` and ``mbox`` arguments. .. _permsgettables: PermsGetTables -------------- Raised when the different permission lists (one per role) are about to be displayed. The current *User* object is available inside the ``user`` argument. Callbacks that listen to this event must return a list of dictionnaries (corresponding to tables). Each dictionnary must contain at least the following elements:: {"id" : "table_id", "title" : _("The title corresponding to this table"), "rel" : "x y", "content" : MyPermClass().get(request)} For ``rel``, replace x and y with the the *Add form* size (the one that appears when you click on the ``Add permission`` button. For ``content``, replace *MyPermClass* with the appropriate name. .. _permsgetclass: PermsGetClass ------------- Raised to retrieve the class (inheriting from ``Permissions``) implementing a specific role. This event is used to add or delete or new instance of this role. The role's name is available inside the ``role`` argument. Callbacks listening to this event must return the class object corresponding to the given ``role`` argument. Parameters ========== A plugin can declare its own parameters. There are two levels available: * 'Administration' parameters : used to configure the plugin, editable inside the *Admin > Settings > Parameters* page, * 'User' parameters : per-user parameters (or preferences), editable inside the *Options > Preferences* page. Playing with parameters ----------------------- To declare a new administration parameter, use the following function:: from modoboa.lib import parameters parameters.register_admin(name, **kwargs) To declare a new user parameter, use the following function:: parameter.register_user(name, **kwargs) Both functions accept extra arguments listed here: * ``type`` : parameter's type, possible values are : ``int``, ``string``, ``list``, ``list_yesno``, * ``deflt`` : default value, * ``help`` : help text, * ``values`` : list of possible values if ``type`` is ``list``. To undeclare parameters (for example when a plugin is disabled is disabled from the interface), use the following function:: parameters.unregister_app(appname) ``appname`` corresponds to your plugin's name, ie. the name of the directory containing the source code. Custom permission levels ======================== Custom permissions roles can be added to Modoboa. If you to want to integrate the default permissions panel (*Admin > Permissions*), each role you add must inherit from the ``Permissions`` (file ``admin/permissions.py``) class and implement all its methods. .. note:: See :ref:`permsgettables` and :ref:`permsgetclass` to learn how to integrate your custom roles.