RetryWhenStream<T> class

Creates a Stream that will recreate and re-listen to the source Stream when the notifier emits a new value. If the source Stream emits an error or it completes, the Stream terminates.

If the retryWhenFactory emits an error a RetryError will be thrown. The RetryError will contain all of the Errors and StackTraces that caused the failure.

Basic Example

new RetryWhenStream<int>(
  () => new Stream<int>.fromIterable(<int>[1]),
  (dynamic error, StackTrace s) => throw error,
).listen(print); // Prints 1

Periodic Example

new RetryWhenStream<int>(
  () => new Observable<int>
      .periodic(const Duration(seconds: 1), (int i) => i)
      .map((int i) => i == 2 ? throw 'exception' : i),
  (dynamic e, StackTrace s) {
    return new Observable<String>
        .timer('random value', const Duration(milliseconds: 200));
  },
).take(4).listen(print); // Prints 0, 1, 0, 1

Complex Example

bool errorHappened = false;
new RetryWhenStream(
  () => new Observable
      .periodic(const Duration(seconds: 1), (i) => i)
      .map((i) {
        if (i == 3 && !errorHappened) {
          throw 'We can take this. Please restart.';
        } else if (i == 4) {
          throw 'It\'s enough.';
        } else {
          return i;
        }
      }),
  (e, s) {
    errorHappened = true;
    if (e == 'We can take this. Please restart.') {
      return new Observable.just('Ok. Here you go!');
    } else {
      return new Observable.error(e);
    }
  },
).listen(
  print,
  onError: (e, s) => print(e),
); // Prints 0, 1, 2, 0, 1, 2, 3, RetryError

Constructors

RetryWhenStream(Stream<T> streamFactory(), RetryWhenStreamFactory retryWhenFactory)
Constructs a Stream that will recreate and re-listen to the source Stream (created by the provided factory method). The retry will trigger whenever the Stream created by the retryWhen factory emits and event.

Properties

retryWhenFactory RetryWhenStreamFactory
The factory method used to create the Stream which triggers a re-listen
final
streamFactory → Stream<T> Function()
The factory method used at subscription time
final
first → Future<T>
The first element of this stream.
read-only, inherited
hashCode → int
The hash code for this object.
read-only, inherited
isBroadcast → bool
Whether this stream is a broadcast stream.
read-only, inherited
isEmpty → Future<bool>
Whether this stream contains any elements.
read-only, inherited
last → Future<T>
The last element of this stream.
read-only, inherited
length → Future<int>
The number of elements in this stream.
read-only, inherited
runtimeType → Type
A representation of the runtime type of the object.
read-only, inherited
single → Future<T>
The single element of this stream.
read-only, inherited

Methods

listen(void onData(T event), { Function onError, void onDone(), bool cancelOnError }) → StreamSubscription<T>
Adds a subscription to this stream. [...]
any(bool test(T element)) → Future<bool>
Checks whether test accepts any element provided by this stream.
inherited
asBroadcastStream({void onListen(StreamSubscription<T> subscription) void onCancel(StreamSubscription<T> subscription) }) → Stream<T>
Returns a multi-subscription stream that produces the same events as this.
inherited
asyncExpand<E>(Stream<E> convert(T event)) → Stream<E>
Transforms each element into a sequence of asynchronous events.
inherited
asyncMap<E>(FutureOr<E> convert(T event)) → Stream<E>
Creates a new stream with each data event of this stream asynchronously mapped to a new event.
inherited
cast<R>() → Stream<R>
Adapt this stream to be a Stream<R>.
inherited
contains(Object needle) → Future<bool>
Returns whether needle occurs in the elements provided by this stream.
inherited
distinct([bool equals(T previous T next) ]) → Stream<T>
Skips data events if they are equal to the previous data event.
inherited
drain<E>([E futureValue ]) → Future<E>
Discards all data on this stream, but signals when it is done or an error occurred.
inherited
elementAt(int index) → Future<T>
Returns the value of the indexth data event of this stream.
inherited
every(bool test(T element)) → Future<bool>
Checks whether test accepts all elements provided by this stream.
inherited
expand<S>(Iterable<S> convert(T element)) → Stream<S>
Transforms each element of this stream into a sequence of elements.
inherited
firstWhere(bool test(T element), { T orElse() }) → Future<T>
Finds the first element of this stream matching test.
inherited
fold<S>(S initialValue, S combine(S previous, T element)) → Future<S>
Combines a sequence of values by repeatedly applying combine.
inherited
forEach(void action(T element)) → Future
Executes action on each element of this stream.
inherited
handleError(Function onError, { bool test(dynamic error) }) → Stream<T>
Creates a wrapper Stream that intercepts some errors from this stream.
inherited
join([String separator = "" ]) → Future<String>
Combines the string representation of elements into a single string.
inherited
lastWhere(bool test(T element), { T orElse() }) → Future<T>
Finds the last element in this stream matching test.
inherited
map<S>(S convert(T event)) → Stream<S>
Transforms each element of this stream into a new stream event.
inherited
noSuchMethod(Invocation invocation) → dynamic
Invoked when a non-existent method or property is accessed.
inherited
pipe(StreamConsumer<T> streamConsumer) → Future
Pipes the events of this stream into streamConsumer.
inherited
reduce(T combine(T previous T element)) → Future<T>
Combines a sequence of values by repeatedly applying combine.
inherited
singleWhere(bool test(T element), { T orElse() }) → Future<T>
Finds the single element in this stream matching test.
inherited
skip(int count) → Stream<T>
Skips the first count data events from this stream.
inherited
skipWhile(bool test(T element)) → Stream<T>
Skip data events from this stream while they are matched by test.
inherited
take(int count) → Stream<T>
Provides at most the first count data events of this stream.
inherited
takeWhile(bool test(T element)) → Stream<T>
Forwards data events while test is successful.
inherited
timeout(Duration timeLimit, { void onTimeout(EventSink<T> sink) }) → Stream<T>
Creates a new stream with the same events as this stream.
inherited
toList() → Future<List<T>>
Collects all elements of this stream in a List.
inherited
toSet() → Future<Set<T>>
Collects the data of this stream in a Set.
inherited
toString() → String
Returns a string representation of this object.
inherited
transform<S>(StreamTransformer<T, S> streamTransformer) → Stream<S>
Applies streamTransformer to this stream.
inherited
where(bool test(T event)) → Stream<T>
Creates a new stream from this stream that discards some elements.
inherited

Operators

operator ==(dynamic other) → bool
The equality operator.
inherited