类目录: src/history/base.js
前言:
对于vue-router来说，有三种路由模式history,hash,abstract, abstract是运行在没有window的环境下的，这三种模式都是继承于history类，history实现了一些共用的方法，对于一开始看vue-router源码来说，可以从这里开始看起。
初始属性
router: Router; 表示VueRouter实例。实例化History类时的第一个参数 base: string; 表示基路径。会用normalizeBase进行规范化。实例化History类时的第二个参数。 current: Route; 表示当前路由(route)。 pending: ?Route; 描述阻塞状态。 cb: (r: Route) => void; 监听时的回调函数。 ready: boolean; 描述就绪状态。 readyCbs: Array<Function>; 就绪状态的回调数组。 readyErrorCbs: Array<Function>; 就绪时产生错误的回调数组。 errorCbs: Array<Function>; 错误的回调数组 // implemented by sub-classes <!-- 下面几个是需要子类实现的方法，这里就先不说了，之后写其他类实现的时候分析 --> +go: (n: number) => void; +push: (loc: RawLocation) => void; +replace: (loc: RawLocation) => void; +ensureURL: (push?: boolean) => void; +getCurrentLocation: () => string;
对于history类来说，主要是下下面两个函数的逻辑
transitionTo
这个方法主要是对路由跳转的封装， location接收的是HTML5History，HashHistory，AbstractHistory， onComplete是成功的回调，onAbort是失败的回调
transitionTo (location: RawLocation, onComplete?: Function, onAbort?: Function) { const route = this.router.match(location, this.current) // 解析成每一个location需要的route this.confirmTransition(route, () => { this.updateRoute(route) onComplete && onComplete(route) this.ensureURL() // fire ready cbs once if (!this.ready) { this.ready = true this.readyCbs.forEach(cb => { cb(route) }) } }, err => { if (onAbort) { onAbort(err) } if (err && !this.ready) { this.ready = true this.readyErrorCbs.forEach(cb => { cb(err) }) } }) }
confirmTransition
这是方法是确认跳转，route是匹配的路由对象， onComplete是匹配成功的回调， 是匹配失败的回调
confirmTransition(route: Route, onComplete: Function, onAbort?: Function) { const current = this.current const abort = err => { // 异常处理函数 if (isError(err)) { if (this.errorCbs.length) { this.errorCbs.forEach(cb => { cb(err) }) } else { warn(false, 'uncaught error during route navigation:') console.error(err) } } onAbort && onAbort(err) } if ( isSameRoute(route, current) && // in the case the route map has been dynamically appended to route.matched.length === current.matched.length ) { this.ensureURL() return abort() } <!-- 根据当前路由对象和匹配的路由：返回更新的路由、激活的路由、停用的路由 --> const { updated, deactivated, activated } = resolveQueue(this.current.matched, route.matched) <!-- 需要执行的任务队列 --> const queue: Array<?NavigationGuard> = [].concat( // beforeRouteLeave 钩子函数 extractLeaveGuards(deactivated), // 全局的beforeHooks勾子 this.router.beforeHooks, // beforeRouteUpdate 钩子函数调用 extractUpdateHooks(updated), // config里的勾子 activated.map(m => m.beforeEnter), // async components resolveAsyncComponents(activated) ) this.pending = route <!-- 对于queue数组所执行的迭代器方法 --> const iterator = (hook: NavigationGuard, next) => { if (this.pending !== route) { return abort() } try { hook(route, current, (to: any) => { if (to === false || isError(to)) { // next(false) -> abort navigation, ensure current URL this.ensureURL(true) abort(to) } else if ( typeof to === 'string' || (typeof to === 'object' && ( typeof to.path === 'string' || typeof to.name === 'string' )) ) { // next('https://www.jb51.net/') or next({ path: 'https://www.jb51.net/' }) -> redirect abort() if (typeof to === 'object' && to.replace) { this.replace(to) } else { this.push(to) } } else { // confirm transition and pass on the value next(to) } }) } catch (e) { abort(e) } } runQueue(queue, iterator, () => { const postEnterCbs = [] const isValid = () => this.current === route <!-- beforeRouteEnter 钩子函数调用 --> const enterGuards = extractEnterGuards(activated, postEnterCbs, isValid) const queue = enterGuards.concat(this.router.resolveHooks) <!-- 迭代运行queue --> runQueue(queue, iterator, () => { if (this.pending !== route) { return abort() } this.pending = null onComplete(route) if (this.router.app) { this.router.app.$nextTick(() => { postEnterCbs.forEach(cb => { cb() }) }) } }) }) }
结语:
每一次总结，都是对之前读源码的再一次深入的了解