StreamProvider<T> class Null safety

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.

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:

Inheritance

Constructors

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

Properties

builder TransitionBuilder?
Syntax sugar for obtaining a BuildContext that can read the provider created. [...]
final, inherited
hashCode int
The hash code for this object. [...]
@nonVirtual, 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() → _InheritedProviderElement<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.info}) String
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 ==(Object other) bool
The equality operator. [...]
@nonVirtual, inherited