# Wizard

A wizard is a finite state machine.

There is also a more practical introduction into wizards.

class trytond.wizard.Wizard(session_id)

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

Class attributes are:

Wizard.__name__

  The unique name to reference the wizard throughout the platform.

Wizard.start_state

  The name of the starting state.

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 client side action keywords.

Wizard.__rpc__

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

Wizard.states

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

trytond.wizard.model

  The `Model` class on which the wizard is executed.

trytond.wizard.record

  The `Model` instance on which the wizard is executed.

trytond.wizard.records

  The list of `Model` instances on which the wizard is executed.

Class methods are:

classmethod Wizard.__setup__()

  Setup the class before adding into the `Pool`.

classmethod Wizard.__post_setup__()

  Setup the class after added into the `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 trytond.wizard.State

  The base for any wizard state.

Instance attributes are:

State.name

  The name of the state.

## StateView

class trytond.wizard.StateView(model_name, view, buttons)

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

  The form is defined by the `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 `on_change()` and `on_change_with()` for the default values.

Instance attributes are:

StateView.model_name

  The name of the `ModelView`.

StateView.view

  The XML id of the form view.

StateView.buttons

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

Instance methods are:

StateView.get_view(wizard, state_name)

  Return the view definition like `fields_view_get()`.

  `wizard` is a `Wizard` instance.

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

StateView.get_defaults(wizard, state_name, fields)

  Return default values for the fields.

  `wizard` is a `Wizard` instance.

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

  `fields` is the list of field names.

StateView.get_values(wizard, state_name, fields)

  Return values for the fields.

  `wizard` is a `Wizard` instance.

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

  `fields` is the list of field names.

StateView.get_buttons(wizard, state_name)

  Return button definitions of the wizard.

  `wizard` is a `Wizard` instance.

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

## StateTransition

class trytond.wizard.StateTransition

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

## StateAction

class trytond.wizard.StateAction(action_id)

  A `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:

StateAction.action_id

  The XML id of the `ir.action`.

Instance methods are:

StateAction.get_action()

  Return the `ir.action` definition.

## StateReport

class trytond.wizard.StateReport(report_name)

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

## Button

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

  Define of a wizard button.

Instance attributes are:

Button.string

  The label display on the button.

Button.state

  The next state to reach if button is clicked.

Button.icon

  The name of the icon to display on the button.

Button.default

  A boolean to set it as default on the form.

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.