redux_future's Introduction

redux_future

A Redux Middleware for handling Dart Futures as actions, with support for loading & optimistic payloads.

The futureMiddleware can be attached to the Redux Store upon construction.

Once attached, you can store.dispatch a Future or FutureAction, and the futureMiddleware will intercept it.

If the Future / FutureAction completes successfully, a FutureFulfilledAction will be dispatched with the result of the future.
If the Future / FutureAction fails, a FutureRejectedAction will be dispatched containing the error that was returned.

Examples

main() {
  // First, create a reducer that knows how to handle the Future Actions:
  // `FutureFulfilledAction` and `FutureRejectedAction`.
  String exampleReducer(String state, action) {
    if (action is String) {
      return action;
    } else if (action is FutureFulfilledAction<String>) {
      return action.result;
    } else if (action is FutureRejectedAction<Exception>) {
      return action.error.toString();
    }
  
    return state;
  }
  
  // Next, create a Store that includes `futureMiddleware`. It will
  // intercept all `FutureAction`s that are dispatched.
  final store = new Store(
    exampleReducer,
    middleware: [futureMiddleware],
  );
  
  // Next, dispatch some actions!
  
  // In this example, once the Future completes, a `FutureFulfilledAction`
  // will be dispatched with "Hi" as the result. The `exampleReducer` will
  // take the result of this action and update the state of the Store!
  store.dispatch(new Future.value("Hi"));
  
  // In this example, the initialAction String "Fetching" will be
  // immediately dispatched. After the future completes, the
  // "Search Results" will be dispatched.
  store.dispatch(new FutureAction(
    new Future.value("Search Results"),
    initialAction: "Fetching"));
  
  // In this example, the future will complete with an error. When that
  // happens, a `FutureRejectedAction` will be dispatched to your store,
  // and the state will be updated by the `exampleReducer`.
  store.dispatch(new Future.error("Oh no!"));
}