class abstract

The basic implementation of the entity responsible for all presentation logic, providing properties and data for the widget, and keep relations with the business logic. Business logic represented in the form of ElementaryModel.

WidgetModel is a working horse of the Elementary library. It unites the trio of 'widget - widget model - model'. So the inheritors of WidgetModel parameterized by an inheritor of the ElementaryWidget and an inheritor of the ElementaryModel. This mean that this WidgetModel subclass encapsulate all required logic for the concrete ElementaryWidget subclass that mentioned as parameter and only for it. Also this WidgetModel subclass uses exactly the mentioned ElementaryModel subclass as an available contract of business logic.

It is common for inheritors to implement the expanded from IWidgetModel interface that describes special contract for the relevant ElementaryWidget subclass. Moreover using the contract is preferable way because this interface explicitly shows available properties and methods for declarative part (for ElementaryWidget).

Approach to update

It is a rare case when ElementaryWidget completely rebuild. The most common case is a partial rebuild of UI parts. In order to get this, using publishers can be helpful. Declare any publishers which you prefer and update their values in suitable conditions. In the declarative part just use these publishers for describe parts of the UI, which depends on them. Here is a far from complete list of options for use as publishers: Stream, ChangeNotifier, StateNotifier, EntityStateNotifier.

The part of Elementary Lifecycle

Base class contains all internal mechanisms and process that need to guarantee the conceived behavior for the Elementary library.

initWidgetModel is called only once for lifecycle of the WidgetModel in the really beginning before the first build. It can be used for initiate a starting state of the WidgetModel.

didUpdateWidget called whenever widget instance in the tree has been updated. Common case where rebuild comes from the top. This method is a good place for update state of the WidgetModel based on the new configuration of widget. When this method is called is just a signal for decide what exactly should be updated or rebuilt. The fact of update doesn't mean that build method of the widget will be called. Set new values to publishers for rebuild concrete parts of the UI.

didChangeDependencies called whenever dependencies which WidgetModel subscribed with BuildContext change. When this method is called is just a signal for decide what exactly should be updated or rebuilt. The fact of the call doesn't mean that build method of the widget will be called. Set new values to publishers for rebuild concrete parts of the UI.

deactivate called when the WidgetModel with Elementary removed from the tree.

activate called when WidgetModel with Elementary are reinserted into the tree after having been removed via deactivate.

dispose called when WidgetModel is going to be permanently destroyed.

reassemble called whenever the application is reassembled during debugging, for example during the hot reload.

onErrorHandle called when the ElementaryModel handle error with the ElementaryModel.handleError method. Can be useful for general handling errors such as showing snack-bars.

Implemented types

IWidgetModel

Mixed in types

Diagnosticable

Implementers

MockWidgetModelMixin

Constructors

WidgetModel(M _model): Creates an instance of the WidgetModel.

Properties

context → BuildContext: The location in the tree where this widget builds.
no setter
hashCode → int: The hash code for this object.
no setterinherited
isMounted → bool: Whether WidgetModel and Elementary are currently mounted in the tree.
no setter
model → M: Instance of ElementaryModel for this WidgetModel.
no setter
runtimeType → Type: A representation of the runtime type of the object.
no setterinherited
widget → W: Widget that uses this WidgetModel for building part of the user interface.
no setter

Methods

activate() → void: Called when this WidgetModel and Elementary are reinserted into the tree after having been removed via deactivate.
deactivate() → void: Called when this WidgetModel and Elementary are removed from the tree.
debugFillProperties(DiagnosticPropertiesBuilder properties) → void: Add additional properties associated with the node.
inherited
didChangeDependencies() → void: Called when a dependency (by Build Context) of this Widget Model changes.
didUpdateWidget(W oldWidget) → void: Called whenever the widget configuration is changed.
dispose() → void: Called when Elementary with this WidgetModel is removed from the tree permanently. Should be used for preparation to be garbage collected.
initWidgetModel() → void: Called while the first build for initialization of this WidgetModel.
noSuchMethod(Invocation invocation) → dynamic: Invoked when a nonexistent method or property is accessed.
inherited
onErrorHandle(Object error) → void: Called whenever ElementaryModel.handleError is called.
reassemble() → void: Called whenever the application is reassembled during debugging, for example during hot reload. Most cases therefore do not need to do anything in the reassemble method.
setupTestElement(BuildContext? testElement) → void: Method for associate another element to this WidgetModel. MUST be used only for testing purposes.
setupTestWidget(W? testWidget) → void: Method for associate another instance of the widget to this WidgetModel. MUST be used only for testing purposes.
toDiagnosticsNode({String? name, DiagnosticsTreeStyle? style}) → DiagnosticsNode: Returns a debug representation of the object that is used by debugging tools and by DiagnosticsNode.toStringDeep.
inherited
toString({DiagnosticLevel minLevel = DiagnosticLevel.info}) → String: A string representation of this object.
inherited
toStringShort() → String: A brief description of this object, usually just the runtimeType and the hashCode.
inherited

Operators

operator ==(Object other) → bool: The equality operator.
inherited