Provider

// Provider把store放到context里，所有的子元素可以直接取到storeimport React from 'react'import PropTypes from 'prop-types'import {bindActionCreators} from './utils.js'export const connect = (mapStateToProps=state=>state,mapDispatchToProps={})=>(WrapComponent)=>{    return class ConnectComponent extends React.Component{        static contextTypes = {            store:PropTypes.object        }        constructor(props, context){            super(props, context)            this.state = {                props:{}            }        }        componentDidMount(){            const {store} = this.context            store.subscribe(()=>this.update())            this.update()        }        update(){            const {store} = this.context            const stateProps = mapStateToProps(store.getState())            const dispatchProps = bindActionCreators(mapDispatchToProps, store.dispatch)            this.setState({                props:{                    ...this.state.props,                    ...stateProps,                    ...dispatchProps                    }            })        }        render(){            return 
            }    }}export class Provider extends React.Component{    static childContextTypes = {        store: PropTypes.object    }    getChildContext(){        return {store:this.store}    }    constructor(props, context){        super(props, context)        this.store = props.store    }    render(){        return this.props.children    }}

utils.js

export function createStore(reducer, enhancer){    if (enhancer) {        return enhancer(createStore)(reducer)    }    let currentState = {}    let currentListeners = []    function getState(){        return currentState    }    function subscribe(listener){        currentListeners.push(listener)    }    function dispatch(action){        currentState = reducer(currentState, action)        currentListeners.forEach(v=>v())        return action    }    dispatch({type:'@IMOOC/WONIU-REDUX'})    return { getState, subscribe, dispatch}}// 自定义applyMiddleware函数export function applyMiddleware(...middlewares){    return createStore=>(...args)=>{        const store = createStore(...args)        let dispatch = store.dispatch        const midApi = {            getState:store.getState,            dispatch:(...args)=>dispatch(...args)        }        const middlewareChain = middlewares.map(middleware=>middleware(midApi))        dispatch = compose(...middlewareChain)(store.dispatch)        return {            ...store,            dispatch        }    }}// 自定义compose函数export function compose(...funcs){    if (funcs.length==0) {        return arg=>arg    }    if (funcs.length==1) {        return funcs[0]    }    return funcs.reduce((ret,item)=> (...args)=>ret(item(...args)))}function bindActionCreator(creator, dispatch){    return (...args) => dispatch(creator(...args))}export function bindActionCreators(creators,dispatch){    return Object.keys(creators).reduce((ret,item)=>{        ret[item] = bindActionCreator(creators[item],dispatch)        return ret    },{})}