dva

React and redux based, lightweight and elm-style framework. (Inspired by choo)

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Table of Contents

• Features
• Demos
• Getting Started
• Creating an App
• Concepts
• API
• FAQ
• Read More
• LICENSE

Features

• based on redux, redux-saga and react-router: stand on the shoulders of giants
• small api: only 5 methods, there's not a lot to learn
• elm cocepts: organize model with reducers, effects and subscriptions
• mobile and react-native support: cross platform
• dynamic model and router: split large app and load on demand
• plugin system: make dva extendable, e.g. use dva-loading to avoid write showLoading and hideLoading hundreds of times
• hmr support with babel-plugin-dva-hmr

Demos

• HackerNews (repo, 详解如何一步步实现)
• Count (jsfiddle)
• Popular Products
• Friend List
• User Dashboard

Getting Started

This is how dva app organized, with only 5 api. View Count Example for more details.

import dva, { connect } from 'dva';

// 1. Create app
const app = dva();

// 2. Add plugins (optionally)
app.use(plugin);

// 3. Register models
app.model(model);

// 4. Connect components and models
const App = connect(mapStateToProps)(Component);

// 5. Config router with Components
app.router(routes);

// 6. Start app
app.start('#root');

You can follow Getting Started to make a Count App step by step.

Creating an App

We recommend to use dva-cli for boilerplating your app.

// Install dva-cli
$ npm install dva-cli -g

// Create app and start
$ dva new myapp
$ cd myapp
$ npm install
$ npm start

But if you like create-react-app, feel free to read Creating dva app with create-react-app.

Concepts

View Concepts for detail explain on Model, State, Action, dispatch, Reducer, Effect, Subscription, Router and Route Components.

API

app = dva(opts)

Initialize a new dva app. Takes an optional object of handlers that is passed to app.use. Besides, you can config history and initialState here.

• opts.history: the history for router, default: hashHistory
• opts.initialState: initialState of the app, default: {}

If you want to use browserHistory instead of hashHistory:

import { browserHistory } from 'dva/router';
const app = dva({
  history: browserHistory,
});

app.use(hooks)

Register an object of hooks on the application.

Support these hooks:

• onError(fn): called when an effect or subscription emit an error
• onAction(array|fn): called when an action is dispatched, used for registering redux middleware, support Array for convenience
• onStateChange(fn): called after a reducer changes the state
• onReducer(fn): used for apply reducer enhancer
• onEffect(fn): used for wrapping effect to add custom behavior, e.g. dva-loading for automatical loading state
• onHmr(fn): used for hot module replacement
• extraReducers(object): used for adding extra reducers, e.g. redux-form needs extra form reducer

app.model(obj)

Create a new model. Takes the following arguments:

• namespace: namespace the model
• state: initial value
• reducers: synchronous operations that modify state. Triggered by actions. Signature of (state, action) => state, same as Redux.
• effects: asynchronous operations that don't modify state directly. Triggered by actions, can call actions. Signature of (action, { put, call, select }),
• subscriptions: asynchronous read-only operations that don't modify state directly. Can call actions. Signature of ({ dispatch, history }).

put(action) in effects, and dispatch(action) in subscriptions

Send a new action to the models. put in effects is the same as dispatch in subscriptions.

e.g.

yield put({
  type: actionType,
  payload: attachedData,
  error: errorIfHave
});

or

dispatch({
  type: actionType,
  payload: attachedData,
  error: errorIfHave
});

When dispatch action inside a model, we don't need to add namespace prefix. And if ouside a model, we should add namespace separated with a /, e.g. namespace/actionType.

call(asyncFunction)

Call async function. Support promise.

e.g.

const result = yield call(api.fetch, { page: 1 });

select(function)

Select data from global state.

e.g.

const count = yield select(state => state.count);

A typical model example:

app.model({
  namespace: 'count',
  state: 0,
  reducers: {
    add(state) { return state + 1; },
    minus(state) { return state - 1; },
  },
  effects: {
    *addDelay(action, { call, put }) {
      yield call(delay, 1000);
      yield put({ type: 'add' });
    },
  },
  subscriptions: {
    // Monitor keyboard input
    keyboard({ dispatch }) {
      return key('ctrl+up', () => { dispatch({ type: 'addDelay'}); });
    },
  },
});

And another complex model example from dva-hackernews.

app.router(({ history }) => routes)

Config router. Takes a function with arguments { history }, and expects router config. It use the same api as react-router, return jsx elements or JavaScript Object for dynamic routing.

e.g.

import { Router, Route } from 'dva/routes';
app.router(({ history } => ({
  <Router history={ history }>
    <Route path="/" component={App} />
  </Router>
});

More on react-router/docs.

app.start(selector?)

Start the application. selector is optional. If no selector arguments, it will return a function that return JSX elements.

Installation

$ npm install dva

FAQ

Why is it called dva?

dva is a hero from overwatch. She is beautiful and cute, and dva is the shortest and available one on npm when creating it.

Which packages was dva built on?

• views: react
• models: redux, react-redux, redux-saga
• router: react-router
• http: whatwg-fetch

Is it production ready?

Sure.

Does it support IE8?

No.

Does it support react-native?

Yes. Try to get started with dva-example-react-native.

Read More

• dva Knowledgemap - All knowledge points needed to create a dva app.
• dva 简介：Why dva and What's dva
• 教程：教你如何一步步完成一个中型应用
• 升级文档：Upgrade to 1.0.0
• 支付宝前端应用架构的发展和选择: 从 roof 到 redux 再到 dva
• React + Redux 最佳实践
• 从 0 开始实现 react 版本的 hackernews (基于 dva)

License

MIT