ConnectionState enum Null safety

The state of connection to an asynchronous computation.

The usual flow of state is as follows:

  1. none, maybe with some initial data.
  2. waiting, indicating that the asynchronous operation has begun, typically with the data being null.
  3. active, with data being non-null, and possible changing over time.
  4. done, with data being non-null.

See also:

  • AsyncSnapshot, which augments a connection state with information received from the asynchronous computation.
Inheritance

Constructors

ConnectionState()
const

Values

none → const ConnectionState

Not currently connected to any asynchronous computation.

For example, a FutureBuilder whose FutureBuilder.future is null.

ConnectionState()
waiting → const ConnectionState

Connected to an asynchronous computation and awaiting interaction.

ConnectionState()
active → const ConnectionState

Connected to an active asynchronous computation.

For example, a Stream that has returned at least one value, but is not yet done.

ConnectionState()
done → const ConnectionState

Connected to a terminated asynchronous computation.

ConnectionState()

Properties

hashCode → int
The hash code for this object.
read-onlyinherited
index → int
A numeric identifier for the enumerated value.
read-onlyinherited
runtimeType → Type
A representation of the runtime type of the object.
read-onlyinherited

Methods

noSuchMethod(Invocation invocation) → dynamic
Invoked when a non-existent method or property is accessed.
inherited
toString() → String
A string representation of this object.
inherited

Operators

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

Constants

values → const List<ConnectionState>
A constant List of the values in this enum, in order of their declaration.
[none, waiting, active, done]