react-router-dom@4.3.0 || react-router@4.4.1
react-router 使用方法
配置 router.js
import React, { Component } from 'react';
import { Switch, Route } from 'react-router-dom';
const router = [{
path: '/',
exact: true,
component:importPath({
loader: () => import(/* webpackChunkName:"home" */ "pages/home/index.js"),
}),
},]
const Routers = () => (
<main>
<Switch>
{
router.map(({component,path,exact},index)=>{
return <Route exact={exact} path={path} component={component} key={path} />
})
}
</Switch>
</main>
);
export default Routers;
入口 index.js
import {HashRouter} from 'react-router-dom';
import React from 'react';
import ReactDOM from 'react-dom';
import Routers from './router';
ReactDOM.render (
<HashRouter>
<Routers />
</HashRouter>,
document.getElementById ('App')
);
home.js
import { withRouter } from "react-router-dom";
@withRouter
class Home extends React.Component<PropsType, stateType> {
constructor(props: PropsType) {
super(props);
this.state = {};
}
goPath=()=>{
this.props.history.push('/home')
}
render() {
return (
<div onClick={this.goPath}>home</div>
);
}
export default Home;
react-router 源码解析
下面代码中会移除部分的类型检查和提醒代码，突出重点代码
第一步 Switch react-router
function _possibleConstructorReturn(self, call) {
if (!self) {
throw new ReferenceError("this hasn't been initialised - super() hasn't been called");
}
if(call&&(typeof call === "object" || typeof call === "function") ){
return call
}else {
return self
}
}
var Switch = function (_React$Component) {
function Switch() {
//使用传递进来的组件覆盖本身
return _possibleConstructorReturn(this, _React$Component.apply(this, arguments));
}
Switch.prototype.render = function render() {
var route = this.context.router.route;
var children = this.props.children;
var location = this.props.location || route.location;
var match = void 0,child = void 0;
//检查element是否是react组件，初始match为null,
React.Children.forEach(children, function (element) {
//如果match符合，forEach不会进入该if
if (match == null && React.isValidElement(element)) {
var _element$props = element.props,
pathProp = _element$props.path,
exact = _element$props.exact,
strict = _element$props.strict,
sensitive = _element$props.sensitive,
from = _element$props.from;
var path = pathProp || from;
child = element;
//检查当前配置是否符合,
match = matchPath(location.pathname, { path: path, exact: exact, strict: strict, sensitive: sensitive }, route.match);
}
});
//如果有匹配元素，则返回克隆child
return match ? React.cloneElement(child, { location: location, computedMatch: match }) : null;
};
return Switch;
}(React.Component);
总结：switch根据location.pathname,path,exact,strict,sensitive获取元素并返回element
第二步 Route react-router
var Route = function (_React$Component) {
function Route() {
var _temp, _this, _ret;
//获取参数
for (var _len = arguments.length, args = Array(_len), _key = 0; _key < _len; _key++) {
args[_key] = arguments[_key];
}
//修改this
return _ret = (
_temp = (_this = _possibleConstructorReturn(this, _React$Component.call.apply(_React$Component, [this].concat(args))), _this),
//检查当前元素是否符合match
_this.state = {match: _this.computeMatch(_this.props,_this.context.router)},_temp),
//这里是真正return
_possibleConstructorReturn(_this, _ret);
}
// 设置content
Route.prototype.getChildContext = function getChildContext() {
return {
router: _extends({}, this.context.router, {
route: {
location: this.props.location || this.context.router.route.location,
match: this.state.match
}
})
};
};
// 根据参数检查当前元素是否符合匹配规则
Route.prototype.computeMatch = function computeMatch(_ref, router) {
var computedMatch = _ref.computedMatch,
location = _ref.location,
path = _ref.path,
strict = _ref.strict,
exact = _ref.exact,
sensitive = _ref.sensitive;
if (computedMatch) return computedMatch;
var route = router.route;
var pathname = (location || route.location).pathname;
return matchPath(pathname, { path: path, strict: strict, exact: exact, sensitive: sensitive }, route.match);
};
// 设置match
Route.prototype.componentWillReceiveProps = function componentWillReceiveProps(nextProps, nextContext) {
this.setState({
match: this.computeMatch(nextProps, nextContext.router)
});
};
Route.prototype.render = function render() {
var match = this.state.match;
var _props = this.props,
children = _props.children,
component = _props.component,
render = _props.render;
var _context$router = this.context.router,
history = _context$router.history,
route = _context$router.route,
staticContext = _context$router.staticContext;
var location = this.props.location || route.location;
var props = { match: match, location: location, history: history, staticContext: staticContext };
//检查route 是否有component组
if (component) return match ? React.createElement(component, props) : null;
// 检查是否包含render 组件
if (render) return match ? render(props) : null;
// withRouter 使用的方式
if (typeof children === "function") return children(props);
if (children && !isEmptyChildren(children)) return React.Children.only(children);
return null;
};
return Route;
}(React.Component);
总结：route 渲染的方式: component render children,代码示例用的是component,route 是检查当前组件是否符合路由匹配规则并执行创建过程
第三步 HashRouter react-router-dom
import Router from './Router'
import {createHistory} from 'history'
var HashRouter = function (_React$Component) {
function HashRouter() {
var _temp, _this, _ret;
//参数转换为数组
for (var _len = arguments.length, args = Array(_len), _key = 0; _key < _len; _key++) {
args[_key] = arguments[_key];
}
return _ret = (
_temp = (_this = _possibleConstructorReturn(this, _React$Component.call.apply(_React$Component, [this].concat(args))), _this),
_this.history = createHistory(_this.props), _temp), //创建history
_possibleConstructorReturn(_this, _ret); //真正返回的东西 返回this
}
HashRouter.prototype.render = function render() {
// 返回一个Router,并且把history，children传递给Router
return React.createElement(Router, { history: this.history, children: this.props.children });
};
return HashRouter;
}(React.Component);
总结 通过 history库里面 createHistory 创建路由系统
第四部 Router react-router
var Router = function (_React$Component) {
function Router() {
var _temp, _this, _ret;
//获取参数，和其他组件一样
for (var _len = arguments.length, args = Array(_len), _key = 0; _key < _len; _key++) {
args[_key] = arguments[_key];
}
return _ret = (_temp = (_this = _possibleConstructorReturn(this, _React$Component.call.apply(_React$Component, [this].concat(args))), _this), _this.state = {
match: _this.computeMatch(_this.props.history.location.pathname) //返回路由对象
}, _temp), _possibleConstructorReturn(_this, _ret); //返回this
}
// 返回context
Router.prototype.getChildContext = function getChildContext() {
return {
router: _extends({}, this.context.router, {
history: this.props.history,
route: {
location: this.props.history.location,
match: this.state.match
}
})
};
};
Router.prototype.computeMatch = function computeMatch(pathname) {
return {
path: "/",
url: "/",
params: {},
isExact: pathname === "/"
};
};
Router.prototype.componentWillMount = function componentWillMount() {
var _this2 = this;
var _props = this.props,
children = _props.children,
history = _props.history;
// 启动监听 当hash 改变是做一次检查，并返回unlisten 取消事件
this.unlisten = history.listen(function () {
_this2.setState({
match: _this2.computeMatch(history.location.pathname)
});
});
};
//销毁前取消监听
Router.prototype.componentWillUnmount = function componentWillUnmount() {
this.unlisten();
};
// children是HashRouter 传递进来的
Router.prototype.render = function render() {
var children = this.props.children;
return children ? React.Children.only(children) : null;
};
return Router;
}(React.Component);
总结 history是一个JavaScript库，可让您在JavaScript运行的任何地方轻松管理会话历史记录。history抽象出各种环境中的差异，并提供最小的API，使您可以管理历史堆栈，导航，确认导航以及在会话之间保持状态。
第五部 withRouter <react-router>
var withRouter = function withRouter(Component) {
var C = function C(props) {
//获取props
var wrappedComponentRef = props.wrappedComponentRef,
remainingProps = _objectWithoutProperties(props, ["wrappedComponentRef"]);
// Route 组件 children方式
return React.createElement(Route, {
children: function children(routeComponentProps) {
// 这里使用的是route 组件 children(props)
//routeComponentProps 实际等于 { match: match, location: location, history: history, staticContext: staticContext };
return React.createElement(Component, _extends({}, remainingProps, routeComponentProps, {
ref: wrappedComponentRef
}));
}
});
};
C.displayName = "withRouter(" + (Component.displayName || Component.name) + ")";
C.WrappedComponent = Component;
// 该类似于object.assign(C,Component),得到的结果是C
return hoistStatics(C, Component);
};
到这里真个流程基本结束了，这只是react-router的一种使用方式的解析,本文的目的是理解react-router的运行机制,如果有什么错误还望指出,谢谢
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持脚本之家。