StreamProvider<T> class

Listens to a Stream and exposes its content to child and descendants.

Its main use-case is to provide to a large number of a widget the content of a Stream, without caring about reacting to events. A typical example would be to expose the battery level, or a Firebase query.

Trying to use Stream to replace ChangeNotifier is outside of the scope of this class.

It is considered an error to pass a stream that can emit errors without providing a catchError method.

initialData determines the value exposed until the Stream emits a value. If omitted, defaults to null.

By default, StreamProvider considers that the Stream listened uses immutable data. As such, it will not rebuild dependents if the previous and the new value are ==. To change this behavior, pass a custom updateShouldNotify.

See also:

  • Stream, which is listened by StreamProvider.
  • StreamController, to create a Stream.
Inheritance

Constructors

StreamProvider({Key key, @required Create<Stream<T>> create, T initialData, ErrorBuilder<T> catchError, UpdateShouldNotify<T> updateShouldNotify, bool lazy, Widget child})
Creates a Stream using create and subscribes to it. [...]
StreamProvider.value({Key key, @required Stream<T> value, T initialData, ErrorBuilder<T> catchError, UpdateShouldNotify<T> updateShouldNotify, bool lazy, Widget child})
Listens to value and expose it to all of StreamProvider descendants.

Properties

hashCode → int
The hash code for this object.
read-only, inherited
key Key
Controls how one widget replaces another widget in the tree.
final, inherited
runtimeType → Type
A representation of the runtime type of the object.
read-only, inherited

Methods

build(BuildContext context) Widget
Describes the part of the user interface represented by this widget. [...]
inherited
buildWithChild(BuildContext context, Widget child) Widget
A build method that receives an extra child parameter. [...]
inherited
createElement() → _InheritedProvderElement<T>
Creates a StatelessElement to manage this widget's location in the tree. [...]
inherited
debugDescribeChildren() → List<DiagnosticsNode>
Returns a list of DiagnosticsNode objects describing this node's children.
@protected, inherited
debugFillProperties(DiagnosticPropertiesBuilder properties) → void
Add additional properties associated with the node. [...]
inherited
noSuchMethod(Invocation invocation) → dynamic
Invoked when a non-existent method or property is accessed.
inherited
toDiagnosticsNode({String name, DiagnosticsTreeStyle style}) DiagnosticsNode
Returns a debug representation of the object that is used by debugging tools and by DiagnosticsNode.toStringDeep.
inherited
toString({DiagnosticLevel minLevel: DiagnosticLevel.debug}) → String
Returns a string representation of this object.
inherited
toStringDeep({String prefixLineOne: '', String prefixOtherLines, DiagnosticLevel minLevel: DiagnosticLevel.debug}) → String
Returns a string representation of this node and its descendants.
inherited
toStringShallow({String joiner: ', ', DiagnosticLevel minLevel: DiagnosticLevel.debug}) → String
Returns a one-line detailed description of the object.
inherited
toStringShort() → String
A short, textual description of this widget.
inherited

Operators

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