redux-rsync

RSync: Redux async middleware

RSync is an alternative to redux-saga to handle async actions without generator. It makes handling complicated async flow easier and offers a great readability.

Table of Contents

• Demo
• Installation
• Getting Started
• Documentation
• Contributing
• Support + Feedback
• License

Demo

For a demo, click here.

Installation

yarn add redux-rsync

Getting Started

1. Apply rsync middlware redux/index.js

import rootReducer from './reducer'
import rsync from 'redux-rsync'
import { createStore, applyMiddleware } from 'redux'

export const store = createStore(
  rootReducer,
  applyMiddleware(rsync)
)

2. Decorate actions with async or flow metadata

redux/action.js

import api from '../api'

...
export function requestGetUser (payload) {
  return {
    type: 'REQUEST_GET_USER',
    payload,
    meta: {
      async: {
        effect: () => api.user.show(),
        resolve: { type: 'RESOLVE_REQUEST_GET_USER' },
        reject: { type: 'REJECT_REQUEST_GET_USER' },
        take: 'latest'
      }
    }
  }
}
...

redux/flow.js

import { requestGetUser, requestGetPosts } from './action'
import { loadInitialDataParams } from './prepare'

...
export function loadInitialData (payload) {
  return {
    type: 'LOAD_INITIAL_DATA',
    payload,
    meta: {
      flow: {
        actions: [
          [
            {
              effect: requestGetUser,
              break: ({ response }) => !response.data.args.user
            },
            {
              prepare: loadInitialDataParams.requestGetPosts,
              effect: requestGetPosts
            }
          ]
        ],
        resolve: { type: 'RESOLVE_LOAD_INITIAL_DATA' },
        reject: { type: 'REJECT_LOAD_INITIAL_DATA' },
        take: 'every:serial'
      }
    }
  }
}
...

Documentation

RSync works by decorating actions with async and/or flow metadata

• Async
• Flow

Async

Example

import api from '../api'

...
export function requestGetUser (payload) {
  return {
    type: 'REQUEST_GET_USER',
    payload,
    meta: {
      async: {
        effect: () => api.user.show(),
        resolve: { type: 'RESOLVE_REQUEST_GET_USER' },
        reject: { type: 'REJECT_REQUEST_GET_USER' },
        take: 'latest'
      }
    }
  }
}
...

Properties

Property	Type	Value	Description
effect	function	payload => {}	Async side effect to run
resolve	object	{ type: '<ACTION_NAME>' }	Will be dispatched if the effect execution is successful. Payload and effect result/response will be passed to the reducer automatically
reject	object	{ type: '<ACTION_NAME>' }	Will be dispatched if the effect execution is failed. Payload and error will be passed to the reducer automatically
take	string	every:parallel(default), latest	latest: if an action effect still running when another action with the same type is dispatched, then the previous action will be cancelled every:parallel: take all dispatched actions

Flow

Example

// async.js
import api from '../api'

...
export function requestGetUser (payload) {
  return {
    type: 'REQUEST_GET_USER',
    payload,
    meta: {
      async: {
        effect: () => api.user.show(),
        resolve: { type: 'RESOLVE_REQUEST_GET_USER' },
        reject: { type: 'REJECT_REQUEST_GET_USER' },
        take: 'latest'
      }
    }
  }
}

export function requestGetPosts (payload) {
  return {
    type: 'REQUEST_GET_POSTS',
    payload,
    meta: {
      async: {
        effect: () => api.post.index(),
        resolve: { type: 'RESOLVE_REQUEST_GET_POSTS' },
        reject: { type: 'REJECT_REQUEST_GET_POSTS' },
        take: 'latest'
      }
    }
  }
}
...


// flow.js
import { requestGetUser, requestGetPosts } from './action'
import { loadInitialDataParams } from './prepare'

...
export function loadInitialData (payload) {
  return {
    type: 'LOAD_INITIAL_DATA',
    payload,
    meta: {
      flow: {
        actions: [ // will be executed in order
          {
            effect: requestGetUser,
            break: ({ response }) => !response.data.args.user
          },
          {
            prepare: loadInitialDataParams.requestGetPosts,
            effect: requestGetPosts
          },
          [ // to execute multiple async actions in parallel, wrap them inside another array 
            {
              prepare: loadInitialDataParams.doFoo,
              effect: doFoo
            },
            {
              prepare: loadInitialDataParams.doBar,
              effect: doBar
            },
          ]       
        ],
        resolve: { type: 'RESOLVE_LOAD_INITIAL_DATA' },
        reject: { type: 'REJECT_LOAD_INITIAL_DATA' },
        take: 'every:serial'
      }
    }
  }
}
...

Properties

Property	Type	Value	Description
actions	array[object/array] or	[{ effect: () => {}, ... }, ...}]	Array of actions to run. The action will support these following properties: effect, prepare, break The actions will be executed in order. To run the actions in parallel, Wrapping the actions inside another another array will do it. (see example above) effect: function that will return redux action with meta:async property. (see example above) prepare: function to prepare result/response from previous async action into params for the current action break: function to evaluate the result/response from the action. return true to break the flow or return false to continue
resolve	object	{ type: '<ACTION_NAME>' }	Will be dispatched if the effect execution is successful. Effect result/response will be passed to the reducer automatically.
reject	object	{ type: '<ACTION_NAME>' }	Will be dispatched if the effect execution is failed. Error will be passed to the reducer automatically.
take	string	first(default), every:serial, every:parallel	first: will not accept any flow actions with the same type with the one that currently running unti it's done every:serial: take all dispatched flow actions with the same type, put them in a queue and execute them in serial

Contributing

We appreciate feedback and contribution to this repo! Before you get started, please see the following:

• This repo's contribution guide

Support + Feedback

• Use Issues for code-level support
• Use Mail for usage, questions, specific cases

License

MIT