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 piece of code that integrates them into Modoboa. Usually, the *__init__.py* file will contain a complete description of the plugin: * Admin and user parameters * Observed 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 ====================== To create a new plugin, just start a new django application like this (into modoboa's directory):: $ python manage.py startapp Then, you need to register this application using the provided API. Just copy/paste the following example into the *__init__.py* file of the future extension:: from modoboa.extensions import ModoExtension, exts_pool class MyExtension(ModoExtension): name = "myext" label = "My Extension" version = "0.1" description = "A description" url = "myext_root_location" # optional, name is used if not defined def init(self): """This method is called when the extension is activated. """ pass def load(self): """This method is called when Modoboa loads available and activated plugins. Declare parameters and register events here. """ pass def destroy(self): """This function is called when a plugin is disabled from the interface. Unregister parameters and events here. """ pass exts_pool.register_extension(MyExtension) Once done, simply add your plugin's module name to the ``INSTALLED_APPS`` variable located inside *settings.py*. Optionaly, run ``python manage.py syncdb`` if your plugin provides custom tables and ``python manage.py collectstatic`` to update static files. 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 def callback(*args): pass events.register('event', callback) You can also use the custom decorator ``events.observe``:: @events.observe('event') def callback(*args): pass ``event`` is the event's name you want to listen to, ``callback`` is the function that will be called each time this event is raised. Each event impose to callbacks a specific prototype to respect. See below for a detailled list. To stop listening to as specific event, you must use the ``unregister`` function:: events.unregister('event', callback) The parameters are the same than those used with ``register``. Read further to get a complete list and description of all available events. UserLogin --------- Raised when a user logs in. *Callback prototype*:: def callback(request, username, password): pass UserLogout ---------- Raised when a user logs out. *Callback prototype*:: def callback(request): pass .. _usermenudisplay: UserMenuDisplay --------------- Raised when a user menu is about to be displayed. *Callback prototype*:: def callback(target, user): pass The ``target`` argument 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 the 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. *Callback prototype*:: def callback(target, user): pass The ``target`` argument 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. GetStaticContent ---------------- Let extensions add static content (ie. CSS or javascript) to default pages. It is pretty useful for functionalities that don't need a template but need javascript stuff. *Callback prototype*:: def callback(user): pass * ``user`` is a ``User`` instance corresponding to the currently logged in user Callbacks listening to this event must return a list of string. CanCreate --------- Raised just before a user tries to create a new object. *Callback prototype*:: def callback(user): pass * ``user`` is a ``User`` instance Return ``True`` or ``False`` to indicate if this user can respectively create or not create a new ``Domain`` object. CreateDomain ------------ Raised when a new domain is created. *Callback prototype*:: def callback(user, domain): pass * ``user`` corresponds to the ``User`` object creating the domain (its owner) * ``domain`` is a ``Domain`` instance DeleteDomain ------------ Raised when an existing domain is about to be deleted. *Callback prototype*:: def callback(domain): pass * ``domain`` is a ``Domain`` instance DomainAliasCreated ------------------ Raised when a new domain alias is created. *Callback prototype*:: def callback(user, domain_alias): pass * ``user`` is the new domain alias owner (``User`` instance) * ``domain_alias`` is the new domain alias (``DomainAlias`` instance) DomainAliasDeleted ------------------ Raised when an existing domain alias is about to be deleted. *Callback prototype*:: def callback(domain_alias): pass * ``domain_alias`` is a ``DomainAlias`` instance CreateMailbox ------------- Raised when a new mailbox is created. *Callback prototype*:: def callback(user, mailbox): pass * ``user`` is the new mailbox's owner (``User`` instance) * ``mailbox`` is the new mailbox (``Mailbox`` instance) DeleteMailbox ------------- Raised when an existing mailbox is about to be deleted. *Callback prototype*:: def callback(mailbox): pass * ``mailbox`` is a ``Mailbox`` instance ModifyMailbox ------------- Raised when an existing mailbox is modified. *Callback prototype*:: def callback(newmailbox, oldmailbox): pass * ``newmailbox`` is a ``Mailbox`` instance containing the new values * ``oldmailbox`` is a ``Mailbox`` instance containing the old values MailboxAliasCreated ------------------- Raised when a new mailbox alias is created. *Callback prototype*:: def callback(user, mailbox_alias): pass * ``user`` is the new domain alias owner (``User`` instance) * ``mailbox_alias`` is the new mailbox alias (``Alias`` instance) MailboxAliasDeleted ------------------- Raised when an existing mailbox alias is about to be deleted. *Callback prototype*:: def callback(mailbox_alias): pass * ``mailbox_alias`` is an ``Alias`` instance AccountCreated -------------- Raised when a new account is created. *Callback prototype*:: def callback(account): pass * ``account`` is the newly created account (``User`` instance) AccountModified --------------- Raised when an existing account is modified. *Callback prototype*:: def callback(oldaccount, newaccount): pass * ``oldaccount`` is the account before it is modified * ``newaccount`` is the account after the modification AccountDeleted -------------- Raised when an existing account is deleted. *Callback prototype*:: def callback(account): pass * ``oldaccount`` is the account that is going to be deleted ExtraAccountForm ---------------- Let extensions add new forms to the global account edition form (the one with tabs). *Callback prototype*:: def callback(user, account): pass * ``user`` is a ``User`` instance corresponding to the currently logged in user * ``account`` is the account beeing modified (``User`` instance) Callbacks listening to the event must return a list of dictionnaries, each one must contain at least three keys:: {"id" : "", "title" : "", "cls" : TheFormClassName} CheckExtraAccountForm --------------------- When an account is being modified, this event lets extensions check if this account is concerned by a specific form. *Callback prototype*:: def callback(account, form): pass * ``account`` is the ``User`` instance beeing modified * ``form`` is a dictionnary (same content as for ``ExtraAccountForm``) Callbacks listening to this event must return a list containing one Boolean. FillAccountInstances -------------------- When an account is beeing modified, this event is raised to fill extra forms. *Callback prototype*:: def callback(user, account, instances): pass * ``user`` is a ``User`` instance corresponding to the currently logged in user * ``account`` is the ``User`` instance beeing modified * ``instances`` is a dictionnary where the callback will add information needed to fill a specific form .. _getextraroles: GetExtraRoles ------------- Let extensions define new administrative roles. *Callback prototype*:: def callback(user): pass * ``user`` is a ``User`` instance corresponding to the currently logged in user Callbacks listening to this event must return a list of 2uple (two strings) which respect the following format: ``(value, label)``. ExtEnabled ---------- Raised just after an extension has been activated. *Callback prototype*:: def callback(extension): pass * ``extension`` is an ``Extension`` instance ExtDisabled ----------- Raised just after an extension has been disabled. *Callback prototype*:: def callback(extension): pass * ``extension`` is an ``Extension`` instance GetAnnouncement --------------- Some places in the interface let plugins add their own announcement (ie. message). *Callback prototype*:: def callback(target): pass * ``target`` is a string indicating the place where the announcement will appear: * ``loginpage`` : corresponds to the login page Callbacks listening to this event must return a list of string. TopNotifications ---------------- Let extensions add custom content into the top bar. *Callback prototype*:: def callback(user): pass * ``user`` is a ``User`` instance corresponding to the currently logged in user Callbacks listening to this event must return a list of string. ExtraAdminContent ----------------- Let extensions add extra content into the admin panel. *Callback prototype*:: def callback(user, target, currentpage): pass * ``user`` is a ``User`` instance corresponding to the currently logged in user * ``target`` is a string indicating the place where the content will be displayed. Possible values are : ``leftcol`` * ``currentpage`` is a string indicating which page (or section) is displayed. Possible values are : ``domains``, ``identities`` Callbacks listening to this event must return a list of string. PasswordChange -------------- Raised just before a *password change* action. *Callback prototype*:: def callback(user): pass * ``user`` is a ``User`` instance Callbacks listening to this event must return a list containing either ``True`` or ``False``. If at least one ``True`` is returned, the *password change* will be cancelled (ie. changing the password for this user is disabled). 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 administrative roles =========================== Modoboa uses Django's internal permission system. Administrative roles are nothing more than groups (``Group`` instances). If an extension needs to add new roles, it needs to follow those steps: #. Create a new ``Group`` instance. It can be done by providing `fixtures `_ or by creating it into the extension ``init`` function #. A a new listener for the :ref:`getextraroles` event that will return the group's name