When<ASYNC_RESULT_TYPE, RESULT_TYPE> class abstract

A utitlity that asynchronously creates a single value.

By using When, the code dependent on the result will be able to read the state of the asynchronous computation synchronously, handle the loading/error/finalize states, and complete when the computation completes.

A common use-case for When is to easily consume states of an asynchronous operation such as reading a file or making an HTTP request.

Implementers

Constructors

When(AsyncResultBuilderCallback<ASYNC_RESULT_TYPE> builder)
When.value(ASYNC_RESULT_TYPE value)

Properties

asyncValue → ASYNC_RESULT_TYPE
no setter
hashCode int
The hash code for this object.
no setterinherited
runtimeType Type
A representation of the runtime type of the object.
no setterinherited
valueBuilder AsyncResultBuilderCallback<ASYNC_RESULT_TYPE>
no setter

Methods

buildAsyncValue() → void
execute({VoidCallback? onLoading, VoidValueCallback? onComplete, VoidErrorCallback? onError, VoidCallback? onFinally}) Future<void>
Asynchronously executes a computation once with listener callbacks in parameters for the asynchronous computation that may fail into something that is safe to read.
noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
inherited
recreate() When<ASYNC_RESULT_TYPE, RESULT_TYPE>
Recreates a when instance from the given async builder.
refresh({VoidCallback? onLoading, VoidValueCallback? onComplete, VoidErrorCallback? onError, VoidCallback? onFinally}) Future<void>
Asynchronously executes a computation with listener callbacks in parameters for the asynchronous computation that may fail into something that is safe to read.
refreshSnapshots(AsyncSnapshotListenerCallback<RESULT_TYPE, AsyncSnapshot<RESULT_TYPE>> listener, [VoidCallback? onFinally]) Future<void>
Asynchronously executes a computation with listener callbacks in parameters for the asynchronous computation that may fail into something that is safe to read.
snapshots(AsyncSnapshotListenerCallback<RESULT_TYPE, AsyncSnapshot<RESULT_TYPE>> listener, [VoidCallback? onFinally]) Future<void>
Asynchronously executes a computation once with snapshots callbacks in parameters for the asynchronous computation that may fail into something that is safe to read.
toString() String
A string representation of this object.
inherited

Operators

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

Static Methods

future<RESULT_TYPE>(AsyncResultBuilderCallback<Future<RESULT_TYPE>> asyncValueBuilder) WhenFuture<RESULT_TYPE>
A utility that uses WhenFuture for executing Futures with snapshots.