路由管理

  • 前端应用中重要的机制-页面根据 URL 的变化进行切换
  • Uniform Resource Locator
  • 页面+状态(定位)
  • 根据状态渲染不同的组件

核心逻辑简单实现

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// 基于hash实现
const MyRouter = ({ children }) => {
const routes = _.keyBy(
children.map((c) => c.props),
"path",
);
const [hash] = useHash();
const Page = routes[hash.replace("#", "")]?.component;
return Page ? <Page /> : "Not found.";
};


const Route = () => null;
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<div className="sample-pages">
<div className="sider">
<a href="#page1">Page 1</a>
<a href="#page2">Page 2</a>
<a href="#page3">Page 3</a>
<a href="#page4">Page 4</a>
</div>
<div className="exp-15-page-container">
<MyRouter>
<Route path="page1" component={Page1} />
<Route path="page2" component={Page2} />
<Route path="page3" component={Page3} />
<Route path="page4" component={Page4} />
</MyRouter>
</div>
</>



源码探究

具体配置执行了什么

base

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base
类型: string

默认值: "/"

应用的基路径。例如,如果整个单页应用服务在 /app/ 下,然后 base 就应该设为 "/app/"
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//   options: RouterOptions | options.base
export interface RouterOptions {
routes?: RouteConfig[]
mode?: RouterMode
fallback?: boolean
base?: string
linkActiveClass?: string
linkExactActiveClass?: string
parseQuery?: (query: string) => Object
stringifyQuery?: (query: Object) => string
scrollBehavior?: (
to: Route,
from: Route,
savedPosition: Position | void
) => PositionResult | Promise<PositionResult> | undefined | null
}
export default class VueRouter {
static install: () => void
static version: string
static isNavigationFailure: Function
static NavigationFailureType: any
static START_LOCATION: Route

app: any
apps: Array<any>
ready: boolean
readyCbs: Array<Function>
options: RouterOptions
mode: string
history: HashHistory | HTML5History | AbstractHistory
matcher: Matcher
fallback: boolean
beforeHooks: Array<?NavigationGuard>
resolveHooks: Array<?NavigationGuard>
afterHooks: Array<?AfterNavigationHook>

constructor (options: RouterOptions = {}) {
this.app = null
this.apps = []
this.options = options
this.beforeHooks = []
this.resolveHooks = []
this.afterHooks = []
this.matcher = createMatcher(options.routes || [], this)

let mode = options.mode || 'hash'
this.fallback =
mode === 'history' && !supportsPushState && options.fallback !== false
if (this.fallback) {
mode = 'hash'
}
if (!inBrowser) {
mode = 'abstract'
}
this.mode = mode

switch (mode) {
case 'history':
this.history = new HTML5History(this, options.base)
break
case 'hash':
this.history = new HashHistory(this, options.base, this.fallback)
break
case 'abstract':
this.history = new AbstractHistory(this, options.base)
break
default:
if (process.env.NODE_ENV !== 'production') {
assert(false, `invalid mode: ${mode}`)
}
}
}

match (raw: RawLocation, current?: Route, redirectedFrom?: Location): Route {
return this.matcher.match(raw, current, redirectedFrom)
}

get currentRoute (): ?Route {
return this.history && this.history.current
}

init (app: any /* Vue component instance */) {
process.env.NODE_ENV !== 'production' &&
assert(
install.installed,
`not installed. Make sure to call \`Vue.use(VueRouter)\` ` +
`before creating root instance.`
)

this.apps.push(app)

// set up app destroyed handler
// https://github.com/vuejs/vue-router/issues/2639
app.$once('hook:destroyed', () => {
// clean out app from this.apps array once destroyed
const index = this.apps.indexOf(app)
if (index > -1) this.apps.splice(index, 1)
// ensure we still have a main app or null if no apps
// we do not release the router so it can be reused
if (this.app === app) this.app = this.apps[0] || null

if (!this.app) this.history.teardown()
})

// main app previously initialized
// return as we don't need to set up new history listener
if (this.app) {
return
}

this.app = app

const history = this.history

if (history instanceof HTML5History || history instanceof HashHistory) {
const handleInitialScroll = routeOrError => {
const from = history.current
const expectScroll = this.options.scrollBehavior
const supportsScroll = supportsPushState && expectScroll

if (supportsScroll && 'fullPath' in routeOrError) {
handleScroll(this, routeOrError, from, false)
}
}
const setupListeners = routeOrError => {
history.setupListeners()
handleInitialScroll(routeOrError)
}
history.transitionTo(
history.getCurrentLocation(),
setupListeners,
setupListeners
)
}

history.listen(route => {
this.apps.forEach(app => {
app._route = route
})
})
}

beforeEach (fn: Function): Function {
return registerHook(this.beforeHooks, fn)
}

beforeResolve (fn: Function): Function {
return registerHook(this.resolveHooks, fn)
}

afterEach (fn: Function): Function {
return registerHook(this.afterHooks, fn)
}

onReady (cb: Function, errorCb?: Function) {
this.history.onReady(cb, errorCb)
}

onError (errorCb: Function) {
this.history.onError(errorCb)
}

push (location: RawLocation, onComplete?: Function, onAbort?: Function) {
// $flow-disable-line
if (!onComplete && !onAbort && typeof Promise !== 'undefined') {
return new Promise((resolve, reject) => {
this.history.push(location, resolve, reject)
})
} else {
this.history.push(location, onComplete, onAbort)
}
}

replace (location: RawLocation, onComplete?: Function, onAbort?: Function) {
// $flow-disable-line
if (!onComplete && !onAbort && typeof Promise !== 'undefined') {
return new Promise((resolve, reject) => {
this.history.replace(location, resolve, reject)
})
} else {
this.history.replace(location, onComplete, onAbort)
}
}

go (n: number) {
this.history.go(n)
}

back () {
this.go(-1)
}

forward () {
this.go(1)
}

getMatchedComponents (to?: RawLocation | Route): Array<any> {
const route: any = to
? to.matched
? to
: this.resolve(to).route
: this.currentRoute
if (!route) {
return []
}
return [].concat.apply(
[],
route.matched.map(m => {
return Object.keys(m.components).map(key => {
return m.components[key]
})
})
)
}

resolve (
to: RawLocation,
current?: Route,
append?: boolean
): {
location: Location,
route: Route,
href: string,
// for backwards compat
normalizedTo: Location,
resolved: Route
} {
current = current || this.history.current
const location = normalizeLocation(to, current, append, this)
const route = this.match(location, current)
const fullPath = route.redirectedFrom || route.fullPath
const base = this.history.base
const href = createHref(base, fullPath, this.mode)
return {
location,
route,
href,
// for backwards compat
normalizedTo: location,
resolved: route
}
}

getRoutes () {
return this.matcher.getRoutes()
}

addRoute (parentOrRoute: string | RouteConfig, route?: RouteConfig) {
this.matcher.addRoute(parentOrRoute, route)
if (this.history.current !== START) {
this.history.transitionTo(this.history.getCurrentLocation())
}
}

addRoutes (routes: Array<RouteConfig>) {
if (process.env.NODE_ENV !== 'production') {
warn(false, 'router.addRoutes() is deprecated and has been removed in Vue Router 4. Use router.addRoute() instead.')
}
this.matcher.addRoutes(routes)
if (this.history.current !== START) {
this.history.transitionTo(this.history.getCurrentLocation())
}
}
}

其他

react router

应用场景

嵌套路由

URL 中保存页面状态

权限控制