FlowState 🌊

Dead simple Redux and redux-observable library built with RxJS streams. This is an easy way to introduce a stream-based unidirectional dataflow into your app.

Highlights

Inspired by Redux and redux-observable
The state is delivered with streams
Reducers are just functions, no switch-case
Isolate side effects that map back to actions

Install

npm install @kahlil/flow-state

Usage

import { createFlowState } from '@kahlil/flow-state';
const flowState = createFlowState();

Dispatch Actions

In your components dispatch actions by passing the action constant and optionally
an action payload. The payload can be any value.

flowState.dispatch({ type: 'SOME_ACTION', payload: { some: 'state' } });

Create A State Stream Based On Reducers

In a file that you could call Store,
create and expose state streams for your components
by passing the respective reducers.

Here is also the place where you can combine state streams if they
depend on one another.

// A collection of reducers.
const itemListReducers = {
  deleteItem: (action, state) => state
    .filter(item => state.filter(item.id !== action.payload.id)),
  addItem: (action, state) => [...state, action.payload],
  // ...
};
itemListState$ = flowState.createState$(itemListReducers, initialState);

In your component you can now subscribe to the component state stream:

itemListState$.subscribe(state => console.log(state));

Trigger Side Effects

You can trigger your side effects similar to redux-observable
by listening to the actions stream, triggering your side effect
and return a new action.

Each side effect is a function and has to be passed to
flowState.runSideEffects.

The action that the result of each side effect maps to

// An imaginary API.
const serverApi = new serverApi();
const action$ = flowState.getAction$();
const sideEffect1 = action$ => action$
  .filter(action => action.type === 'DELETE_ITEM')
  .switchMap(action => serverApi.deleteItem(action.payload))
  .map(response => ({ type: 'RECEIVE_ITEMS', payload: response }))
  .catch(response => ({ type: 'DELETE_ITEM_ERROR', payload: response.error });
const sideEffect1 = action$ => action$
  .filter(action => action.type === 'ADD_ITEM')
  .switchMap(action => serverApi.addItem(action.payload))
  .map(response => ({ type: 'RECEIVE_ITEMS', payload: response }))
  .catch(response => ({ type: 'ADD_ITEM_ERROR', payload: response.error });
flowState.runSideEffects(sideEffect1, sideEffect2);