ObserverWidgetMixin mixin

Observer observes the observables used in the build method and rebuilds the Widget whenever any of them change. There is no need to do any other wiring besides simply referencing the required observables.

Internally, ObserverWidgetMixin uses a Reaction around the build method.

If your build method does not contain any observables, ObserverWidgetMixin will print a warning on the console. This is a debug-time hint to let you know that you are not observing any observables.

Superclass Constraints

• Widget

Mixin Applications

• StatefulObserverWidget
• StatelessObserverWidget

Properties

hashCode → int

The hash code for this object.

no setter, inherited

key → Key?

Controls how one widget replaces another widget in the tree.

final, inherited

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

warnWhenNoObservables → bool?

Whether to warn when there is no observables in the builder function null means true

no setter

Methods

createElement() → Element

Inflates this configuration to a concrete instance.

inherited

createReaction(dynamic onInvalidate(), {dynamic onError(Object, Reaction)?}) → Reaction

A convenience method used for testing.

debugDescribeChildren() → List<DiagnosticsNode>

Returns a list of DiagnosticsNode objects describing this node's children.

inherited

debugFillProperties(DiagnosticPropertiesBuilder properties) → void

Add additional properties associated with the node.

inherited

getContext() → ReactiveContext

The context within which its reaction should be run. It is the mainContext in most cases.

getName() → String

An identifiable name that can be overriden for debugging.

log(String msg) → void

Convenience method to output console messages as debugging output. Logging usually happens when some internal error needs to be surfaced to the user.

noSuchMethod(Invocation invocation) → dynamic

Invoked when a nonexistent method or property is accessed.

inherited

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

toStringDeep({String prefixLineOne = '', String? prefixOtherLines, DiagnosticLevel minLevel = DiagnosticLevel.debug}) → String

Returns a string representation of this node and its descendants.

inherited

toStringShallow({String joiner = ', ', DiagnosticLevel minLevel = DiagnosticLevel.debug}) → String

Returns a one-line detailed description of the object.

inherited

toStringShort() → String

A short, textual description of this widget.

inherited

Operators

operator ==(Object other) → bool

The equality operator.

inherited