Adds Redux to Flutter Hooks

This package uses flutter_hooks and async_redux packages to add Redux to flutter_hooks.

You have to add the following dependencies to your pubspec.yaml:

dependencies:
  flutter_hooks: ^0.20.5 # or newer
  async_redux: ^23.0.0 # or newer
  flutter_hooks_async_redux: ^1.0.3 # or newer

And then, all features of Flutter Hooks and Async Redux are available for you.

The hooks provided by this package are described below.

useSelector

useSelector lets you select a part of the state and subscribe to updates.

You should give it a function that gets the sate and returns only the part of the state that the widget needs.

Example:

String username 
   = useSelector<AppState, String>((state) => state.username);

Note: If your state is called AppState, you can define your own useAppState hook, like this:

T useAppState<T>(T Function(AppState state) converter, {bool distinct = true}) =>
    useSelector<AppState, T>(converter, distinct: distinct);

By doing so, you simplify accessing state values. For example:

String username = useAppState((state) => state.username);

useDispatch

useDispatch dispatches the action, applying its reducer, and possibly changing the store state. The action may be sync or async.

var dispatch = useDispatch()
dispatch(new MyAction());

useDispatchAndWait

useDispatchAndWait dispatches the action, applying its reducer, and possibly changing the store state. The action may be sync or async. In both cases, it returns a Future that resolves when the action finishes.

var dispatchAndWait = useDispatchAndWait();
var dispatch = useDispatch();
await dispatchAndWait(DoThisFirstAction());
store.dispatch(DoThisSecondAction());

Note: While the state change from the action's reducer will have been applied when the Future resolves, other independent processes that the action may have started may still be in progress.

Note useDispatchAndWait returns Future<ActionStatus>, which means you can also get the final status of the action after you await it:

var status = await dispatchAndWait(MyAction());

useDispatchSync

Dispatches the action, applying its reducer, and possibly changing the store state. However, if the action is ASYNC, it will throw a StoreException.

var dispatch = useDispatchSync();
useDispatchSync(MyAction());

useIsWaiting

With useIsWaiting you can check if:

  • A specific async ACTION is currently being processed.
  • An async action of a specific TYPE is currently being processed.
  • If any of a few given async actions or action types is currently being processed.

If you wait for an action TYPE, then it returns false when:

  • The ASYNC action of the type is NOT currently being processed.
  • If the type is not really a type that extends ReduxAction.
  • The action of the type is a SYNC action (since those finish immediately).

If you wait for an ACTION, then it returns false when:

  • The ASYNC action is NOT currently being processed.
  • If the action is a SYNC action (since those finish immediately).

Trying to wait for any other type of object will return null and throw a StoreException after the async gap.

Examples:

var dispatch = useDispatch();

// Waiting for an action TYPE:
dispatch(MyAction());
var isWaiting = useIsWaiting(MyAction);
if (isWaiting) { // Show a spinner }

// Waiting for an ACTION:
var action = MyAction();
dispatch(action);
var isWaiting = useIsWaiting(action);
if (isWaiting) { // Show a spinner }

// Waiting for any of the given action TYPES:
dispatch(BuyAction());
var isWaiting = useIsWaiting([BuyAction, SellAction]);
if (isWaiting) { // Show a spinner }

useIsFailed, useExceptionFor, useClearExceptionFor

Usage:

// Returns true if the action failed with an UserException:
var isFailed = useIsFailed(MyAction);
if (isFailed) { // Show an error message. }

// Returns the `UserException` of the action that failed.
var exception = useExceptionFor(MyAction);
Text(exception!.reason ?? '');

// Removes the given action from the list of action types that failed.
var clearExceptionFor = useClearExceptionFor(); 
clearExceptionFor(MyAction);

Note these functions accept a ReduxAction, an action Type, or an Iterable of action types. Any other type of object won't work.

Libraries

flutter_hooks_async_redux