rsnext/packages/next-server/lib/router/router.ts
2019-04-04 15:35:20 -05:00

490 lines
16 KiB
TypeScript

/* global __NEXT_DATA__ */
// tslint:disable:no-console
import { ComponentType } from 'react';
import { parse } from 'url';
import mitt, {MittEmitter} from '../mitt';
import { formatWithValidation, getURL, loadGetInitialProps } from '../utils';
function toRoute(path: string): string {
return path.replace(/\/$/, '') || '/'
}
export interface IRouterInterface {
route: string
pathname: string
query: string
asPath: string
}
type RouteInfo = {
Component: ComponentType,
props?: any,
err?: Error
error?: any,
}
type Subscription = (data: {App?: ComponentType} & RouteInfo) => void
type BeforePopStateCallback = (state: any) => boolean
type Context = any
export default class Router implements IRouterInterface {
route: string
pathname: string
query: string
asPath: string
components: {[pathname: string]: RouteInfo}
subscriptions: Set<Subscription>
componentLoadCancel: (() => void) | null
pageLoader: any
_bps: BeforePopStateCallback | undefined
static events: MittEmitter = mitt()
constructor(pathname: string, query: any, as: string, { initialProps, pageLoader, App, Component, err }: {initialProps: any, pageLoader: any, Component: ComponentType, App: ComponentType, err?: Error}) {
// represents the current component key
this.route = toRoute(pathname)
// set up the component cache (by route keys)
this.components = {}
// We should not keep the cache, if there's an error
// Otherwise, this cause issues when when going back and
// come again to the errored page.
if (pathname !== '/_error') {
this.components[this.route] = { Component, props: initialProps, err }
}
this.components['/_app'] = { Component: App }
// Backwards compat for Router.router.events
// TODO: Should be remove the following major version as it was never documented
// @ts-ignore backwards compatibility
this.events = Router.events
this.pageLoader = pageLoader
this.pathname = pathname
this.query = query
this.asPath = as
this.subscriptions = new Set()
this.componentLoadCancel = null
if (typeof window !== 'undefined') {
// in order for `e.state` to work on the `onpopstate` event
// we have to register the initial route upon initialization
this.changeState('replaceState', formatWithValidation({ pathname, query }), as)
window.addEventListener('popstate', this.onPopState)
}
}
static _rewriteUrlForNextExport(url: string): string {
const [pathname, hash] = url.split('#')
// tslint:disable-next-line
let [path, qs] = pathname.split('?')
path = path.replace(/\/$/, '')
// Append a trailing slash if this path does not have an extension
if (!/\.[^/]+\/?$/.test(path)) path += `/`
if (qs) path += '?' + qs
if (hash) path += '#' + hash
return path
}
onPopState = (e: PopStateEvent): void => {
if (!e.state) {
// We get state as undefined for two reasons.
// 1. With older safari (< 8) and older chrome (< 34)
// 2. When the URL changed with #
//
// In the both cases, we don't need to proceed and change the route.
// (as it's already changed)
// But we can simply replace the state with the new changes.
// Actually, for (1) we don't need to nothing. But it's hard to detect that event.
// So, doing the following for (1) does no harm.
const { pathname, query } = this
this.changeState('replaceState', formatWithValidation({ pathname, query }), getURL())
return
}
// If the downstream application returns falsy, return.
// They will then be responsible for handling the event.
if (this._bps && !this._bps(e.state)) {
return
}
const { url, as, options } = e.state
if (process.env.NODE_ENV !== 'production') {
if (typeof url === 'undefined' || typeof as === 'undefined') {
console.warn('`popstate` event triggered but `event.state` did not have `url` or `as` https://err.sh/zeit/next.js/popstate-state-empty')
}
}
this.replace(url, as, options)
};
update(route: string, Component: ComponentType) {
const data = this.components[route]
if (!data) {
throw new Error(`Cannot update unavailable route: ${route}`)
}
const newData = { ...data, Component }
this.components[route] = newData
// pages/_app.js updated
if (route === '/_app') {
this.notify(this.components[this.route])
return
}
if (route === this.route) {
this.notify(newData)
}
}
reload(route: string): Promise<void> {
return new Promise((resolve, reject) => {
delete this.components[route]
this.pageLoader.clearCache(route)
if (route !== this.route) {
return resolve()
}
const { pathname, query } = this
const url = window.location.href
// This makes sure we only use pathname + query + hash, to mirror `asPath` coming from the server.
const as = window.location.pathname + window.location.search + window.location.hash
Router.events.emit('routeChangeStart', url)
this.getRouteInfo(route, pathname, query, as).then((routeInfo) => {
const { error } = routeInfo
if (error && error.cancelled) {
return resolve()
}
this.notify(routeInfo)
if (error) {
Router.events.emit('routeChangeError', error, url)
return reject(error)
}
Router.events.emit('routeChangeComplete', url)
})
})
}
back() {
window.history.back()
}
push(url: string, as: string = url, options = {}) {
return this.change('pushState', url, as, options)
}
replace(url: string, as: string = url, options = {}) {
return this.change('replaceState', url, as, options)
}
change(method: string, _url: string, _as: string, options: any): Promise<boolean> {
return new Promise((resolve, reject) => {
// If url and as provided as an object representation,
// we'll format them into the string version here.
const url = typeof _url === 'object' ? formatWithValidation(_url) : _url
let as = typeof _as === 'object' ? formatWithValidation(_as) : _as
// Add the ending slash to the paths. So, we can serve the
// "<page>/index.html" directly for the SSR page.
if (process.env.__NEXT_EXPORT_TRAILING_SLASH) {
// @ts-ignore this is temporarily global (attached to window)
if (__NEXT_DATA__.nextExport) {
as = Router._rewriteUrlForNextExport(as)
}
}
this.abortComponentLoad(as)
// If the url change is only related to a hash change
// We should not proceed. We should only change the state.
if (this.onlyAHashChange(as)) {
Router.events.emit('hashChangeStart', as)
this.changeState(method, url, as)
this.scrollToHash(as)
Router.events.emit('hashChangeComplete', as)
return true
}
const { pathname, query } = parse(url, true)
// If asked to change the current URL we should reload the current page
// (not location.reload() but reload getInitialProps and other Next.js stuffs)
// We also need to set the method = replaceState always
// as this should not go into the history (That's how browsers work)
// We should compare the new asPath to the current asPath, not the url
if (!this.urlIsNew(as)) {
method = 'replaceState'
}
// @ts-ignore pathname is always a string
const route = toRoute(pathname)
const { shallow = false } = options
Router.events.emit('routeChangeStart', as)
// If shallow is true and the route exists in the router cache we reuse the previous result
// @ts-ignore pathname is always a string
this.getRouteInfo(route, pathname, query, as, shallow).then((routeInfo) => {
const { error } = routeInfo
if (error && error.cancelled) {
return resolve(false)
}
Router.events.emit('beforeHistoryChange', as)
this.changeState(method, url, as, options)
const hash = window.location.hash.substring(1)
// @ts-ignore pathname is always defined
this.set(route, pathname, query, as, { ...routeInfo, hash })
if (error) {
Router.events.emit('routeChangeError', error, as)
throw error
}
Router.events.emit('routeChangeComplete', as)
return resolve(true)
}, reject)
})
}
changeState(method: string, url: string, as: string, options = {}): void {
if (process.env.NODE_ENV !== 'production') {
if (typeof window.history === 'undefined') {
console.error(`Warning: window.history is not available.`)
return
}
// @ts-ignore method should always exist on history
if (typeof window.history[method] === 'undefined') {
console.error(`Warning: window.history.${method} is not available`)
return
}
}
if (method !== 'pushState' || getURL() !== as) {
// @ts-ignore method should always exist on history
window.history[method]({ url, as, options }, null, as)
}
}
getRouteInfo(route: string, pathname: string, query: any, as: string, shallow: boolean = false): Promise<RouteInfo> {
const cachedRouteInfo = this.components[route]
// If there is a shallow route transition possible
// If the route is already rendered on the screen.
if (shallow && cachedRouteInfo && this.route === route) {
return Promise.resolve(cachedRouteInfo)
}
return (new Promise((resolve, reject) => {
if (cachedRouteInfo) {
return resolve(cachedRouteInfo)
}
this.fetchComponent(route).then((Component) => resolve({Component}), reject)
}) as Promise<RouteInfo>).then((routeInfo: RouteInfo) => {
const { Component } = routeInfo
if (process.env.NODE_ENV !== 'production') {
const { isValidElementType } = require('react-is')
if (!isValidElementType(Component)) {
throw new Error(`The default export is not a React Component in page: "${pathname}"`)
}
}
return (new Promise((resolve, reject) => {
const ctx = { pathname, query, asPath: as }
this.getInitialProps(Component, ctx).then((props) => {
routeInfo.props = props
this.components[route] = routeInfo
resolve(routeInfo)
}, reject)
}) as Promise<RouteInfo>)
}).catch((err) => {
return (new Promise((resolve) => {
if (err.code === 'PAGE_LOAD_ERROR') {
// If we can't load the page it could be one of following reasons
// 1. Page doesn't exists
// 2. Page does exist in a different zone
// 3. Internal error while loading the page
// So, doing a hard reload is the proper way to deal with this.
window.location.href = as
// Changing the URL doesn't block executing the current code path.
// So, we need to mark it as a cancelled error and stop the routing logic.
err.cancelled = true
// @ts-ignore TODO: fix the control flow here
return resolve({ error: err })
}
if (err.cancelled) {
// @ts-ignore TODO: fix the control flow here
return resolve({ error: err })
}
resolve(this.fetchComponent('/_error').then((Component) => {
const routeInfo: RouteInfo = { Component, err }
const ctx = { err, pathname, query }
return (new Promise((resolve) => {
this.getInitialProps(Component, ctx).then((props) => {
routeInfo.props = props
routeInfo.error = err
resolve(routeInfo)
}, (gipErr) => {
console.error('Error in error page `getInitialProps`: ', gipErr)
routeInfo.error = err
routeInfo.props = {}
resolve(routeInfo)
})
}) as Promise<RouteInfo>)
}))
}) as Promise<RouteInfo>)
})
}
set(route: string, pathname: string, query: any, as: string, data: RouteInfo): void {
this.route = route
this.pathname = pathname
this.query = query
this.asPath = as
this.notify(data)
}
beforePopState(cb: BeforePopStateCallback) {
this._bps = cb
}
onlyAHashChange(as: string): boolean {
if (!this.asPath) return false
const [ oldUrlNoHash, oldHash ] = this.asPath.split('#')
const [ newUrlNoHash, newHash ] = as.split('#')
// Makes sure we scroll to the provided hash if the url/hash are the same
if (newHash && (oldUrlNoHash === newUrlNoHash) && (oldHash === newHash)) {
return true
}
// If the urls are change, there's more than a hash change
if (oldUrlNoHash !== newUrlNoHash) {
return false
}
// If the hash has changed, then it's a hash only change.
// This check is necessary to handle both the enter and
// leave hash === '' cases. The identity case falls through
// and is treated as a next reload.
return oldHash !== newHash
}
scrollToHash(as: string): void {
const [ , hash ] = as.split('#')
// Scroll to top if the hash is just `#` with no value
if (hash === '') {
window.scrollTo(0, 0)
return
}
// First we check if the element by id is found
const idEl = document.getElementById(hash)
if (idEl) {
idEl.scrollIntoView()
return
}
// If there's no element with the id, we check the `name` property
// To mirror browsers
const nameEl = document.getElementsByName(hash)[0]
if (nameEl) {
nameEl.scrollIntoView()
}
}
urlIsNew(asPath: string): boolean {
return this.asPath !== asPath
}
prefetch(url: string): Promise<void> {
return new Promise((resolve, reject) => {
// Prefetch is not supported in development mode because it would trigger on-demand-entries
if (process.env.NODE_ENV !== 'production' || process.env.__NEXT_EXPERIMENTAL_DEBUG) return
const { pathname } = parse(url)
// @ts-ignore pathname is always defined
const route = toRoute(pathname)
this.pageLoader.prefetch(route).then(resolve, reject)
})
}
async fetchComponent(route: string): Promise<ComponentType> {
let cancelled = false
const cancel = this.componentLoadCancel = () => {
cancelled = true
}
const Component = await this.pageLoader.loadPage(route)
if (cancelled) {
const error: any = new Error(`Abort fetching component for route: "${route}"`)
error.cancelled = true
throw error
}
if (cancel === this.componentLoadCancel) {
this.componentLoadCancel = null
}
return Component
}
async getInitialProps(Component: ComponentType, ctx: Context): Promise<any> {
let cancelled = false
const cancel = () => { cancelled = true }
this.componentLoadCancel = cancel
const { Component: App } = this.components['/_app']
const props = await loadGetInitialProps(App, { Component, router: this, ctx })
if (cancel === this.componentLoadCancel) {
this.componentLoadCancel = null
}
if (cancelled) {
const err: any = new Error('Loading initial props cancelled')
err.cancelled = true
throw err
}
return props
}
abortComponentLoad(as: string): void {
if (this.componentLoadCancel) {
Router.events.emit('routeChangeError', new Error('Route Cancelled'), as)
this.componentLoadCancel()
this.componentLoadCancel = null
}
}
notify(data: RouteInfo): void {
const { Component: App } = this.components['/_app']
this.subscriptions.forEach((fn) => fn({ ...data, App }))
}
subscribe(fn: Subscription): () => void {
this.subscriptions.add(fn)
return () => this.subscriptions.delete(fn)
}
}