Result<T> class sealed

Result is the base class of an enumerable set of subtypes that represent the different states involved in fetching data for a ResultNotifier.

A result can be in one of the following states:

  • Loading: Represents a loading/reloading state, along with the previous data, if any.
  • Data: The result contains some concrete data.
  • Error: Represents an error, along with the previous data, if any.

There is also a special Initial state, which is used as a default state when no other state has been set. This state inherits from Loading and is handled as such in most cases.

Result provides a number of methods for checking (properties of) the current state as well as converting between the different states. It also provides a number of methods for performing actions based on the current state, for instance when. Example:

result.when(
  loading: (data) => const CircularProgressIndicator(),
  error: (error, stackTrace, data) => Text('Error: $error'),
  data: (data) => Text(data),
),
Implementers
Annotations

Properties

data → T?
The last data, if any.
no setter
error → Object?
The last error, if any.
no setter
hasData → bool
Checks if the result contains data, regardless of the result type. Note that this is different from isData.
no setter
hashCode → int
The hash code for this object.
no setteroverride
isCancelled → bool
Checks if the current state is Error and the error is a CancelledException.
no setter
isData → bool
Checks if the result is Data. Note that this is different from if this notifier currently contains data (i.e. hasData).
no setter
isError → bool
Checks if the current state is Error.
no setter
isInitial → bool
Checks if the the result is the Initial loading state.
no setter
isLoading → bool
Checks if the the result is Loading. Note that the initial state (Initial) is also interpreted as a loading state.
no setter
isLoadingData → bool
Checks if the data is currently being loaded, i.e. the current state is Loading but not Initial.
no setter
isReloading → bool
Checks if data is currently being reloaded, i.e. the current state is Loading and hasData.
no setter
lastUpdate → DateTime
The last time the result was updated.
final
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited

Methods

copyWith({T? data, DateTime? lastUpdate}) → Result<T>
Creates a copy of this result with the provided values.
noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
inherited
toCancelled({T? data, DateTime? lastUpdate}) → Result<T>
Attempts to convert the result to cancellation Error.
toData({T? data, T orElse()?, DateTime? lastUpdate}) → Result<T>
Attempts to convert the result to Data.
toError({Object? error, StackTrace? stackTrace, T? data, DateTime? lastUpdate}) → Result<T>
Attempts to convert the result to Error.
toFresh() → Result<T>
Creates a fresh copy of this result, meaning lastUpdate will be set to DateTime.now().
toInitial({T? data, DateTime? lastUpdate}) → Result<T>
Attempts to convert the result to the Initial loading state.
toLoading({T? data, DateTime? lastUpdate}) → Result<T>
Attempts to convert the result to Loading.
toStale() → Result<T>
Creates a stale copy of this result, meaning lastUpdate will be set to zero ms from "epoch".
toString() → String
A string representation of this object.
inherited

Operators

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