ReadableByteStreamController extension type

The ReadableByteStreamController interface of the Streams API represents a controller for a readable byte stream. It allows control of the state and internal queue of a ReadableStream with an underlying byte source, and enables efficient zero-copy transfer of data from the underlying source to a consumer when the stream's internal queue is empty.

An instance of this controller type is created if an underlyingSource object with the property type="bytes" is passed as an argument to the ReadableStream() constructor. The underlyingSource object may also define start() and pull() callback functions. These are called with the controller as a parameter, in order to set up the underlying source, and request data when needed.

The underlying source uses the controller to supply data to the stream via its byobRequest property or enqueue() method. byobRequest is a ReadableStreamBYOBRequest object that represents a pending request from a consumer to make a zero-copy transfer of data direct to a consumer. byobRequest must be used to copy data if it exists (do not use enqueue() in this case)! If the underlying source needs to pass data to the stream and byobRequest is null then the source can call enqueue() to add the data to the stream's internal queues.

Note that the byobRequest is only created in "BYOB mode" when there is a request from a reader and the stream's internal queue is empty. "BYOB mode" is enabled when using a ReadableStreamBYOBReader (typically constructed by calling ReadableStream.getReader with the argument { mode: 'byob' }). It is also enabled when using a default reader and autoAllocateChunkSize is specified in the ReadableController() constructor.

An underlying byte source can also use the controller to close() the stream when all the data has been sent and report errors from the underlying source using error(). The controller's desiredSize property is used to apply "backpressure", informing the underlying source of the size of the internal queue (small values indicate that the queue is filling up, hinting to the underlying source that it is be desirable to pause or throttle the inflow).

Note that even though the controller is primarily used by the underlying byte source, there is no reason it cannot be stored used by other parts of the system to signal the stream.

API documentation sourced from MDN Web Docs.

on
Implemented types
Available extensions

Properties

asString → String

Available on JSAny, provided by the JSAnyExtension extension

no setter
asString → String?

Available on JSAny?, provided by the JSAnyNullableExtension extension

no setter
byobRequest → ReadableStreamBYOBRequest?
The byobRequest read-only property of the ReadableByteStreamController interface returns the current BYOB request, or null if there are no pending requests.
no setter
desiredSize → double?
The desiredSize read-only property of the ReadableByteStreamController interface returns the number of bytes required to fill the stream's internal queue to its "desired size".
no setter
entries → Iterable<MapEntry<String, dynamic>>

Available on JSObject, provided by the JSObjectExtension extension

no setter
hashCode → int
The hash code for this object.
no setterinherited
isDefinedAndNotNull → bool

Available on JSAny?, provided by the NullableUndefineableJSAnyExtension extension

no setter
isElement → bool

Available on JSObject?, provided by the JSObjectWebExtension extension

no setter
isHTMLElement → bool

Available on JSObject?, provided by the JSObjectWebExtension extension

no setter
isNode → bool

Available on JSObject?, provided by the JSObjectWebExtension extension

no setter
isNull → bool

Available on JSAny?, provided by the NullableUndefineableJSAnyExtension extension

Whether this value corresponds to JavaScript null.
no setter
isTruthy → JSBoolean

Available on JSAny?, provided by the JSAnyOperatorExtension extension

The result of !!this in JavaScript.
no setter
isUndefined → bool

Available on JSAny?, provided by the NullableUndefineableJSAnyExtension extension

Whether this value corresponds to JavaScript undefined.
no setter
isUndefinedOrNull → bool

Available on JSAny?, provided by the NullableUndefineableJSAnyExtension extension

no setter
keys → Iterable<String>

Available on JSObject, provided by the JSObjectExtension extension

no setter
not → JSBoolean

Available on JSAny?, provided by the JSAnyOperatorExtension extension

The result of !this in JavaScript.
no setter
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited

Methods

add(JSAny? any) → JSAny

Available on JSAny?, provided by the JSAnyOperatorExtension extension

The result of this + any in JavaScript.
and(JSAny? any) → JSAny?

Available on JSAny?, provided by the JSAnyOperatorExtension extension

The result of this && any in JavaScript.
as<T extends JSObject>() → T?

Available on JSObject, provided by the JSObjectExtension extension

callMethod<R extends JSAny?>(JSAny method, [JSAny? arg1, JSAny? arg2, JSAny? arg3, JSAny? arg4]) → R

Available on JSObject, provided by the JSObjectUnsafeUtilExtension extension

Calls method on this JSObject with up to four arguments.
callMethodVarArgs<R extends JSAny?>(JSAny method, [List<JSAny?>? arguments]) → R

Available on JSObject, provided by the JSObjectUnsafeUtilExtension extension

Calls method on this JSObject with a variable number of arguments.
close() → void
The close() method of the ReadableByteStreamController interface closes the associated stream.
dartify() → Object?

Available on JSAny?, provided by the JSAnyUtilityExtension extension

Converts a JavaScript JSON-like value to the Dart equivalent if possible.
delete(JSAny property) → JSBoolean

Available on JSObject, provided by the JSObjectUnsafeUtilExtension extension

Deletes the property with key property from this JSObject.
divide(JSAny? any) → JSAny

Available on JSAny?, provided by the JSAnyOperatorExtension extension

The result of this / any in JavaScript.
enqueue(ArrayBufferView chunk) → void
The enqueue() method of the ReadableByteStreamController interface enqueues a given chunk on the associated readable byte stream (the chunk is copied into the stream's internal queues).
equals(JSAny? any) → JSBoolean

Available on JSAny?, provided by the JSAnyOperatorExtension extension

The result of this == any in JavaScript.
error([JSAny? e]) → void
The error() method of the ReadableByteStreamController interface causes any future interactions with the associated stream to error with the specified reason.
exponentiate(JSAny? any) → JSAny

Available on JSAny?, provided by the JSAnyOperatorExtension extension

The result of this ** any in JavaScript.
get(String key) → Object?

Available on JSObject, provided by the JSObjectExtension extension

getProperty<R extends JSAny?>(JSAny property) → R

Available on JSObject, provided by the JSObjectUnsafeUtilExtension extension

The value of the property key property of this JSObject.
greaterThan(JSAny? any) → JSBoolean

Available on JSAny?, provided by the JSAnyOperatorExtension extension

The result of this > any in JavaScript.
greaterThanOrEqualTo(JSAny? any) → JSBoolean

Available on JSAny?, provided by the JSAnyOperatorExtension extension

The result of this >= any in JavaScript.
has(String property) → bool

Available on JSObject, provided by the JSObjectUnsafeUtilExtension extension

Shorthand helper for hasProperty to check whether this JSObject contains the property key property, but takes and returns a Dart value.
hasProperty(JSAny property) → JSBoolean

Available on JSObject, provided by the JSObjectUnsafeUtilExtension extension

Whether or not this JSObject contains the property key property.
instanceof(JSFunction constructor) → bool

Available on JSAny?, provided by the JSAnyUtilityExtension extension

Whether this JSAny? is an instanceof constructor.
instanceOfString(String constructorName) → bool

Available on JSAny?, provided by the JSAnyUtilityExtension extension

Whether this JSAny? is an instanceof the constructor that is defined by constructorName, which is looked up in the globalContext.
isA<T extends JSAny?>() → bool

Available on JSAny?, provided by the JSAnyUtilityExtension extension

Whether this JSAny? is an instance of the JavaScript type that is declared by T.
lessThan(JSAny? any) → JSBoolean

Available on JSAny?, provided by the JSAnyOperatorExtension extension

The result of this < any in JavaScript.
lessThanOrEqualTo(JSAny? any) → JSBoolean

Available on JSAny?, provided by the JSAnyOperatorExtension extension

The result of this <= any in JavaScript.
modulo(JSAny? any) → JSAny

Available on JSAny?, provided by the JSAnyOperatorExtension extension

The result of this % any in JavaScript.
multiply(JSAny? any) → JSAny

Available on JSAny?, provided by the JSAnyOperatorExtension extension

The result of this * any in JavaScript.
noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
inherited
notEquals(JSAny? any) → JSBoolean

Available on JSAny?, provided by the JSAnyOperatorExtension extension

The result of this != any in JavaScript.
or(JSAny? any) → JSAny?

Available on JSAny?, provided by the JSAnyOperatorExtension extension

The result of this || any in JavaScript.
put(Object key, Object? value) → void

Available on JSObject, provided by the JSObjectExtension extension

setProperty(JSAny property, JSAny? value) → void

Available on JSObject, provided by the JSObjectUnsafeUtilExtension extension

Write the value of property key property of this JSObject.
strictEquals(JSAny? any) → JSBoolean

Available on JSAny?, provided by the JSAnyOperatorExtension extension

The result of this === any in JavaScript.
strictNotEquals(JSAny? any) → JSBoolean

Available on JSAny?, provided by the JSAnyOperatorExtension extension

The result of this !== any in JavaScript.
subtract(JSAny? any) → JSAny

Available on JSAny?, provided by the JSAnyOperatorExtension extension

The result of this - any in JavaScript.
toMap() → Map<String, dynamic>

Available on JSObject, provided by the JSObjectExtension extension

toString() → String
A string representation of this object.
inherited
typeofEquals(String typeString) → bool

Available on JSAny?, provided by the JSAnyUtilityExtension extension

Whether the result of typeof on this JSAny? is typeString.
unsignedRightShift(JSAny? any) → JSNumber

Available on JSAny?, provided by the JSAnyOperatorExtension extension

The result of this >>> any in JavaScript.

Operators

operator ==(Object other) → bool
The equality operator.
inherited
operator [](String property) → JSAny?

Available on JSObject, provided by the JSObjectUnsafeUtilExtension extension

Shorthand helper for getProperty to get the value of the property key property of this JSObject, but takes a Dart value.
operator []=(String property, JSAny? value) → void

Available on JSObject, provided by the JSObjectUnsafeUtilExtension extension

Shorthand helper for setProperty to write the value of the property key property of this JSObject, but takes a Dart value.