dart:async

StreamTransformer<S, T> class

Transforms a Stream.

When a stream's Stream.transform method is invoked with a StreamTransformer, the stream calls the bind method on the provided transformer. The resulting stream is then returned from the Stream.transform method.

Conceptually, a transformer is simply a function from Stream to Stream that is encapsulated into a class.

It is good practice to write transformers that can be used multiple times.

All other transforming methods on Stream, such as Stream.map, Stream.where or Stream.expand can be implemented using Stream.transform. A StreamTransformer is thus very powerful but often also a bit more complicated to use.

Implemented by

• StreamTransformerBase
• WebSocketTransformer

Constructors

StreamTransformer(StreamSubscription<T> onListen(Stream<S> stream, bool cancelOnError))

const

factory

Creates a StreamTransformer based on the given onListen callback. [...]

StreamTransformer.fromHandlers({void handleData(S data, EventSink<T> sink), void handleError(Object error, StackTrace stackTrace, EventSink<T> sink), void handleDone(EventSink<T> sink) })

factory

Creates a StreamTransformer that delegates events to the given functions. [...]

Properties

hashCode → int

read-only, inherited

The hash code for this object. [...]

runtimeType → Type

read-only, inherited

A representation of the runtime type of the object.

Methods

bind(Stream<S> stream) → Stream<T>

Transforms the provided stream. [...]

cast<RS, RT>() → StreamTransformer<RS, RT>

Provides a StreamTrasformer<RS, RT> view of this stream transformer. [...]

noSuchMethod(Invocation invocation) → dynamic

inherited

Invoked when a non-existent method or property is accessed. [...]

toString() → String

inherited

Returns a string representation of this object.

Operators

operator ==(dynamic other) → bool

inherited

The equality operator. [...]

Static Methods

castFrom<SS, ST, TS, TT>(StreamTransformer<SS, ST> source) → StreamTransformer<TS, TT>

Adapts source to be a StreamTransfomer<TS, TT>. [...]