Fusio(n) Reactor

Worflow management based on Elm Architecture

Fusio(n) Reactor is a basic declarative worflow mangement that is inspired by Elm Architecture. It comes with out of the box connectors for Redux, but it is useful in many other contexts, or with other libraries.

If you need complex workflows, use Redux Saga, it is way more powerful.

Concepts

While Redux only handles state changes, this library handles both state changes and declarative side-effects in the same place. By having them colocated, it provides a clear view of the results.

A worflow is a function that will take a state and a context and will return the next state and a description of the side-effects to be performed.

The library comes with some helpers that facilitate that (reference, task, chain, batch. error). It also offers a set of helpers to connect to Redux (enhanceReducer, createMiddleware).

Reference

The reference is just a simple way to create a worflow with no side-effects. Does nothing except wrap the state and context and pass them further. This is the ideal way to only change the state.

type Workflow = (state: State, context: Context) => Change

Task

The task is a way to wrap a promise into a workflow.

type Task = (input: (ctx: Context) => Promise<Context>) => Workflow

Chain

A chain is allowing composition of worflows that will be run in sequence. It also allows the to handle errors on the previous workflows.

type Chain = (onSuccess?: Workflow, onError?: Workflow) => (workflow: Workflow) => Workflow

Batch

A batch is allowing composition of worflows that will be run in parallel. It merges all the worflows into one after every one of them finishes.

type Batch = (worflows: Array<Workflow>) => Workflow

Error

The error wrapper transforms a failed worflow into a successful one. This is probably rarely needed, but in some cases we want to catch the error and continue our worflow.

type Error = (worflow: Workflow) => Workflow

Setup

yarn add fusio

or

npm install --save fusio

Usage

Before you start import the functions from the library

import { reference, task, chain, batch, error, enhanceReducer, createMiddleware } from 'fusio'

Connect to Redux

// Create the store
import { createStore, applyMiddleware } from 'redux'

// Map
const updates = {
  CREATE_PLAYER
}

// Create the saga middleware
const fusioMiddleware = createMiddleware(key => update[key])

// Mount it on the Store
const store = createStore(enhanceReducer(reducer), applyMiddleware(fusioMiddleware))

// Load the dispatch value
store.dispatch({ type: 'CREATE_PLAYER', payload: { name: 'John Doe' } })

License

MIT