當前版本: 3.0.3
類目錄: src/history/base.js
前言:
對於vue-router來說,有三種路由模式history,hash,abstract, abstract是運行在沒有window的環境下的,這三種模式都是繼承於history類,history實現了一些共用的方法,對於一開始看vue-router源碼來說,可以從這裏開始看起。
初始屬性
router: Router; 表示VueRouter實例。實例化History類時的第一個參數
base: string; 表示基路徑。會用normalizeBase進行規範化。實例化History類時的第二個參數。
current: Route; 表示當前路由(route)。
pending: ?Route; 描述阻塞狀態。
cb: (r: Route) => void; 監聽時的回調函數。
ready: boolean; 描述就緒狀態。
readyCbs: Array<Function>; 就緒狀態的回調數組。
readyErrorCbs: Array<Function>; 就緒時產生錯誤的回調數組。
errorCbs: Array<Function>; 錯誤的回調數組
// implemented by sub-classes
<!-- 下面幾個是需要子類實現的方法,這裏就先不說了,之後寫其他類實現的時候分析 -->
+go: (n: number) => void;
+push: (loc: RawLocation) => void;
+replace: (loc: RawLocation) => void;
+ensureURL: (push?: boolean) => void;
+getCurrentLocation: () => string;
對於history類來說,主要是下下面兩個函數的邏輯
transitionTo
這個方法主要是對路由跳轉的封裝, location接收的是HTML5History,HashHistory,AbstractHistory, onComplete是成功的回調,onAbort是失敗的回調
transitionTo (location: RawLocation, onComplete?: Function, onAbort?: Function) {
const route = this.router.match(location, this.current) // 解析成每一個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
這是方法是確認跳轉,route是匹配的路由對象, onComplete是匹配成功的回調, 是匹配失敗的回調
confirmTransition(route: Route, onComplete: Function, onAbort?: Function) {
const current = this.current
const abort = err => { // 異常處理函數
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()
}
<!-- 根據當前路由對象和匹配的路由: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)
<!-- 需要執行的任務隊列 -->
const queue: Array<?NavigationGuard> = [].concat(
// beforeRouteLeave 鉤子函數
extractLeaveGuards(deactivated),
// 全局的beforeHooks勾子
this.router.beforeHooks,
// beforeRouteUpdate 鉤子函數調用
extractUpdateHooks(updated),
// config裏的勾子
activated.map(m => m.beforeEnter),
// async components
resolveAsyncComponents(activated)
)
this.pending = route
<!-- 對於queue數組所執行的迭代器方法 -->
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('/') or next({ path: '/' }) -> 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 鉤子函數調用 -->
const enterGuards = extractEnterGuards(activated, postEnterCbs, isValid)
const queue = enterGuards.concat(this.router.resolveHooks)
<!-- 迭代運行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() })
})
}
})
})
}
結語:
每一次總結,都是對之前讀源碼的再一次深入的瞭解