KeyStream<T> class
abstract
Class to expose a stream of AtKey based on the provided query parameters
KeyStream exposes a stream where each stream element represents data for a single AtKey
Pass the convert
callback function to define how an AtKey and AtValue will converted into elements of the
stream. To filter AtKeys that will be included in this stream, you may apply a custom regex
filter, or pass in
sharedBy
and/or sharedWith
atSigns. By default shouldGetKeys
is enabled, which will initially populate the
stream with available keys that match the regex
, sharedBy
, and sharedWith
filters. You may also override
the atClientManager
if necessary.
In addition to KeyStream, there are collection based versions for Iterable, List, Set, and Map represented by IterableKeyStream, ListKeyStream, SetKeyStream, and MapKeyStream respectively.
KeyStreams can be used with Flutter's StreamBuilders to achieve seamless data flow from the at_client straight to the user interface. For example, to get a stream containing all messages from '@alice' to '@bob' in a list:
ListKeyStream stream = ListKeyStream(
convert: (key, value) => value,
regex: r'\.message',
sharedBy: '@alice',
sharedWith: '@bob'
);
When switching atSigns, all KeyStreams will self-dispose to prevent any complications during the development
process. If you would like to dipose of a KeyStream sooner, you may do so using KeyStream.dipose()
.
If your KeyStream was created as state of a StatefulWidget it is recommended that you dispose of it in the widget:
@override
void dispose() async {
await stream.dispose();
super.dispose();
}
Constructors
Properties
-
controller
→ StreamController<
T?> -
An internal controller used to manage this Stream interface.
finalinherited
- convert → dynamic Function(AtKey key, AtValue value)
-
convert
is a required conversion function for converting AtKey:AtValue pairs from notifications into elements of this Stream or Stream's collection.finalinherited - disposeOnAtsignChange ↔ bool
-
getter/setter pairinherited
-
first
→ Future<
T?> -
The first element of this stream.
no setterinherited
- hashCode → int
-
The hash code for this object.
no setterinherited
- isBroadcast → bool
-
Whether this stream is a broadcast stream.
no setterinherited
-
isEmpty
→ Future<
bool> -
Whether this stream contains any elements.
no setterinherited
- isPaused → bool
-
Whether the
notificationSubscription
is currently paused.no setterinherited -
last
→ Future<
T?> -
The last element of this stream.
no setterinherited
-
length
→ Future<
int> -
The number of elements in this stream.
no setterinherited
-
notificationSubscription
↔ StreamSubscription<
AtNotification> -
A subscription that listens to notifications.
getter/setter pairinherited
-
onError
↔ FutureOr<
void> Function(Object exception) -
Callback function when an error occurs in the keystream.
latefinalinherited
- regex → String?
-
regex
is a regex pattern to filter notifications on.finalinherited - runtimeType → Type
-
A representation of the runtime type of the object.
no setterinherited
-
Use
sharedBy
to filter to only keys that were sent bysharedBy
.finalinherited -
Use
sharedWith
to filter to only keys that were sent tosharedWith
.finalinherited - shouldGetKeys → bool
-
When
shouldGetKeys
istrue
this Stream should be preloaded with keys that matchregex
,sharedBy
, andsharedWith
.finalinherited -
single
→ Future<
T?> -
The single element of this stream.
no setterinherited
Methods
-
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 -
dispose(
) → Future< void> -
Closes the stream and cancels the notification subscription.
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
index
th 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< void> -
Executes
action
on each element of this stream.inherited -
getKeys(
) → Future< void> -
A function that preloads this Stream with keys that match
regex
,sharedBy
, andsharedWith
.inherited -
handleError(
Function onError, {bool test(dynamic error)?}) → Stream< T?> -
Creates a wrapper Stream that intercepts some errors from this stream.
inherited
-
handleNotification(
AtKey key, AtValue value, String? operation) → void -
How to handle notifications received by the internal
notificationSubscription
.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 -
listen(
void onData(T? event)?, {Function? onError, void onDone()?, bool? cancelOnError}) → StreamSubscription< T?> -
Adds a subscription to this stream.
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 nonexistent method or property is accessed.
inherited
-
pause(
[Future< void> ? resumeSignal]) → void -
Requests that the
notificationSubscription
stream pauses events until further notice.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 -
resume(
) → void -
Resumes the
notificationSubscription
after a pause.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 -
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 ==(
Object other) → bool -
The equality operator.
inherited