Workflow type plugins are now responsible for state and transition schema

Previously settings for states were stored in both the Workflow config entity and the schema of the @WorkflowType plugin associated with a Workflow config entity.

Config schema impact

Old schema:

id: editorial
label: 'Editorial workflow'
states:
  archived:
    label: Archived
    weight: 5
type_settings:
  states:
    archived:
      published: false
      default_revision: true

New schema:

id: editorial
label: 'Editorial workflow'
type_settings:
  states:
    archived:
      label: Archived
      weight: 5
      published: false
      default_revision: true

Old way to add a state:

$workflow->addState('test_state', 'Test state');

New way:

$workflow->getTypePlugin()->addState('test_state', 'Test state');

Impact on Workflow(Interface) (entity type)

The full list of methods that have moved from WorkflowInterface to WorkflowTypeInterface is (with no BC layer):

• addState()
• hasState()
• getStates()
• getState()
• setStateLabel()
• setStateWeight()
• deleteState()
• getInitialState()
• addTransition()
• getTransition()
• hasTransition()
• getTransitions()
• getTransitionsForState()
• getTransitionFromStateToState()
• hasTransitionFromStateToState()
• setTransitionLabel()
• setTransitionWeight()
• setTransitionFromStates()
• deleteTransition()

Impact on WorkflowType(Interface) (plugin type)

To accommodate this schema, the plugin forms are now defined in individual form classes referenced in the @WorkflowType annotation. These forms replace the methods that were previously implemented directly on the plugin type. Previously, it was impossible to influence the initial states & transitions of a workflow, but that's no longer a problem since each @WorkflowType plugin now controls schema + storage, so now plugins can just implement ConfigurablePluginInterface::defaultConfiguration().

Therefore the following methods have been removed from WorkflowTypeInterface:

• initializeWorkflow()
• buildStateConfigurationForm()
• buildTransitionConfigurationForm()

(Validate and submit handlers had to be set manually with advanced Form API constructs.)

What's added: WorkflowTypeInterface now extends PluginWithFormsInterface, which is what makes it possible to reference form classes from the @WorkflowType annotation.

The workflows UI currently makes use of three forms: configure, state and transition. The new form classes should implement PluginFormInterface and may extend WorkflowTypeConfigureFormBase,
WorkflowTypeStateFormBase or WorkflowTypeTransitionFormBase respectively.