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)

Properties

controller ↔ StreamController<T>
read / write
retryWhenFactory RetryWhenStreamFactory
final
streamFactory → Stream<T> Function()
final
subscription ↔ StreamSubscription<T>
read / write
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