.. _ref-wizard:
.. module:: trytond.wizard


Wizard
======

A wizard is a `finite state machine`_.

There is also a more :ref:`practical introduction into wizards
<topics-wizard>`.

.. _`finite state machine`: http://en.wikipedia.org/wiki/Finite-state_machine

.. class:: Wizard(session_id)

   This is the base for any wizard.
   It contains the engine for the finite state machine.
   A wizard must have some :class:`State` instance attributes that the engine
   uses.

Class attributes are:

.. attribute:: Wizard.__name__

   The unique name to reference the wizard throughout the platform.

.. attribute:: Wizard.start_state

   The name of the starting state.

.. attribute:: Wizard.end_state

   The name of the ending state.

   If an instance method with this name exists on the wizard, it is called on
   deletion of the wizard and it may return one of the :ref:`client side action
   keywords <topics-views-client-actions>`.

.. attribute:: Wizard.__rpc__

   Same as :attr:`trytond.model.Model.__rpc__`.

.. attribute:: Wizard.states

   A dictionary with state name as key and :class:`State` as value.

.. attribute:: model

   The :class:`~trytond.model.Model` class on which the wizard is executed.

.. attribute:: record

   The :class:`~trytond.model.Model` instance on which the wizard is executed.

.. attribute:: records

   The list of :class:`~trytond.model.Model` instances on which the wizard is
   executed.

Class methods are:

.. classmethod:: Wizard.__setup__()

   Setup the class before adding into the :class:`~trytond.pool.Pool`.

.. classmethod:: Wizard.__post_setup__()

   Setup the class after added into the :class:`~trytond.pool.Pool`.

.. classmethod:: Wizard.__register__(module_name)

   Register the wizard.

.. classmethod:: Wizard.create()

   Create a session for the wizard and returns a tuple containing the session
   id, the starting and ending state.

.. classmethod:: Wizard.delete(session_id)

   Delete the session.

.. classmethod:: Wizard.execute(session_id, data, state_name)

   Execute the wizard for the state.

   ``session_id`` is a session id.

   ``data`` is a dictionary with the session data to update.

   ``active_id``, ``active_ids``, ``active_model`` and ``action_id`` must be
   set in the context according to the records on which the wizard is run.


State
-----

.. class:: State()

   The base for any wizard state.

Instance attributes are:

.. attribute:: State.name

   The name of the state.


StateView
---------

.. class:: StateView(model_name, view, buttons)

   A :class:`StateView` is a state that will display a form in the client.

   The form is defined by the :class:`~trytond.model.ModelView` with the name
   ``model_name``, the ``XML`` id in ``view`` and the ``buttons``.
   The default values of the view can be set with a method on wizard having the
   same name as the state but starting with ``default_``.
   The values of the view can be also set with a method on wizard having the
   same name as the state but starting with ``value_``.

   .. note::
      The difference between default values and values is that the client calls
      :meth:`~trytond.model.ModelView.on_change` and
      :meth:`~trytond.model.ModelView.on_change_with` for the default values.

Instance attributes are:

.. attribute:: StateView.model_name

   The name of the :class:`~trytond.model.ModelView`.

.. attribute:: StateView.view

   The XML id of the form view.

.. attribute:: StateView.buttons

   The list of :class:`Button` instances to display on the form.

Instance methods are:

.. method:: StateView.get_view(wizard, state_name)

   Return the view definition like
   :meth:`~trytond.model.ModelView.fields_view_get`.

   ``wizard`` is a :class:`Wizard` instance.

   ``state_name`` is the name of the :class:`StateView` instance.

.. method:: StateView.get_defaults(wizard, state_name, fields)

   Return default values for the fields.

   ``wizard`` is a :class:`Wizard` instance.

   ``state_name`` is the name of the :class:`State`.

   ``fields`` is the list of field names.

.. method:: StateView.get_values(wizard, state_name, fields)

   Return values for the fields.

   ``wizard`` is a :class:`Wizard` instance.

   ``state_name`` is the name of the :class:`State`.

   ``fields`` is the list of field names.

.. method:: StateView.get_buttons(wizard, state_name)

   Return button definitions of the wizard.

   ``wizard`` is a :class:`Wizard` instance.

   ``state_name`` is the name of the :class:`StateView` instance.


StateTransition
---------------

.. class:: StateTransition()

   A :class:`StateTransition` brings the wizard to the ``state`` returned by
   the method having the same name as the state but starting with
   ``transition_``.


StateAction
-----------

.. class:: StateAction(action_id)

   A :class:`StateTransition` which let the client launch an ``ir.action``.

   This action definition can be customized with a method on wizard having the
   same name as the state but starting with ``do_``.

Instance attributes are:

.. attribute:: StateAction.action_id

   The XML id of the ``ir.action``.

Instance methods are:

.. method:: StateAction.get_action()

   Return the ``ir.action`` definition.


StateReport
-----------

.. class:: StateReport(report_name)

   A :class:`StateAction` which find the report action by name instead of XML
   id.


Button
------

.. class:: Button(string, state[, icon[, default[, validate]]])

    Define of a wizard button.

Instance attributes are:

.. attribute:: Button.string

   The label display on the button.

.. attribute:: Button.state

   The next state to reach if button is clicked.

.. attribute:: Button.icon

   The name of the icon to display on the button.

.. attribute:: Button.default

   A boolean to set it as default on the form.

.. attribute:: Button.validate

   A boolean or None.

   If ``True``, validation of the form will occur, if ``False`` it won't.
   If the value is ``None`` the validation will occur only if the state of the
   button is not the wizard ending state.
