IsolateBlocConsumer<B extends IsolateBlocBase<Object?, S> , S> constructor
- Key? key,
- required BlocWidgetBuilder<
S> builder, - required BlocWidgetListener<
S> listener, - IsolateBlocWrapper? bloc,
- BlocBuilderCondition<
S> ? buildWhen, - IsolateBlocListenerCondition<
S> ? listenWhen,
IsolateBlocConsumer exposes a builder and listener in order react to new
states.
IsolateBlocConsumer is analogous to a nested IsolateBlocListener
and IsolateBlocBuilder
but reduces the amount of boilerplate needed.
IsolateBlocConsumer should only be used when it is necessary to both rebuild UI
and execute other reactions to state changes in the bloc.
IsolateBlocConsumer takes a required BlocWidgetBuilder
and BlocWidgetListener
and an optional bloc,
BlocBuilderCondition
, and BlocListenerCondition
.
If the bloc parameter is omitted, IsolateBlocConsumer will automatically
perform a lookup using IsolateBlocProvider
and the current BuildContext
.
IsolateBlocConsumer<BlocA, BlocAState>(
listener: (context, state) {
// do stuff here based on BlocA's state
},
builder: (context, state) {
// return widget here based on BlocA's state
}
)
An optional listenWhen and buildWhen can be implemented for more
granular control over when listener and builder are called.
The listenWhen and buildWhen will be invoked on each bloc state
change.
They each take the previous state
and current state
and must return
a bool which determines whether or not the builder and/or listener
function will be invoked.
The previous state
will be initialized to the state
of the bloc when
the IsolateBlocConsumer is initialized.
listenWhen and buildWhen are optional and if they aren't implemented,
they will default to true
.
IsolateBlocConsumer<BlocA, BlocAState>(
listenWhen: (previous, current) {
// return true/false to determine whether or not
// to invoke listener with state
},
listener: (context, state) {
// do stuff here based on BlocA's state
},
buildWhen: (previous, current) {
// return true/false to determine whether or not
// to rebuild the widget with state
},
builder: (context, state) {
// return widget here based on BlocA's state
}
)
Implementation
const IsolateBlocConsumer({
Key? key,
required this.builder,
required this.listener,
this.bloc,
this.buildWhen,
this.listenWhen,
}) : super(key: key);