rsnext/packages/next/client/page-loader.js
JJ Kasper b274fe39d3
Update method for attaching GS(S)P identifier to page (#10859)
* Update to use separate export instead of attaching to Component to identify GS(S)P pages

* Handle initialProps being undefined
2020-03-05 23:15:10 -05:00

361 lines
11 KiB
JavaScript

import { parse } from 'url'
import mitt from '../next-server/lib/mitt'
import { isDynamicRoute } from './../next-server/lib/router/utils/is-dynamic'
import { getRouteMatcher } from './../next-server/lib/router/utils/route-matcher'
import { getRouteRegex } from './../next-server/lib/router/utils/route-regex'
function hasRel(rel, link) {
try {
link = document.createElement('link')
return link.relList.supports(rel)
} catch {}
}
const relPrefetch =
hasRel('preload') && !hasRel('prefetch')
? // https://caniuse.com/#feat=link-rel-preload
// macOS and iOS (Safari does not support prefetch)
'preload'
: // https://caniuse.com/#feat=link-rel-prefetch
// IE 11, Edge 12+, nearly all evergreen
'prefetch'
const hasNoModule = 'noModule' in document.createElement('script')
/** @param {string} route */
function normalizeRoute(route) {
if (route[0] !== '/') {
throw new Error(`Route name should start with a "/", got "${route}"`)
}
route = route.replace(/\/index$/, '/')
if (route === '/') return route
return route.replace(/\/$/, '')
}
function appendLink(href, rel, as) {
return new Promise((res, rej, link) => {
link = document.createElement('link')
link.crossOrigin = process.crossOrigin
link.href = href
link.rel = rel
if (as) link.as = as
link.onload = res
link.onerror = rej
document.head.appendChild(link)
})
}
export default class PageLoader {
constructor(buildId, assetPrefix) {
this.buildId = buildId
this.assetPrefix = assetPrefix
this.pageCache = {}
this.pageRegisterEvents = mitt()
this.loadingRoutes = {}
if (process.env.__NEXT_GRANULAR_CHUNKS) {
this.promisedBuildManifest = new Promise(resolve => {
if (window.__BUILD_MANIFEST) {
resolve(window.__BUILD_MANIFEST)
} else {
window.__BUILD_MANIFEST_CB = () => {
resolve(window.__BUILD_MANIFEST)
}
}
})
}
/** @type {Promise<Set<string>>} */
this.promisedSsgManifest = new Promise(resolve => {
if (window.__SSG_MANIFEST) {
resolve(window.__SSG_MANIFEST)
} else {
window.__SSG_MANIFEST_CB = () => {
resolve(window.__SSG_MANIFEST)
}
}
})
}
// Returns a promise for the dependencies for a particular route
getDependencies(route) {
return this.promisedBuildManifest.then(
man =>
(man[route] &&
man[route].map(
url => `${this.assetPrefix}/_next/${encodeURI(url)}`
)) ||
[]
)
}
/**
* @param {string} href the route href (file-system path)
* @param {string} asPath the URL as shown in browser (virtual path); used for dynamic routes
*/
getDataHref(href, asPath) {
const getHrefForSlug = (/** @type string */ path) =>
`${this.assetPrefix}/_next/data/${this.buildId}${
path === '/' ? '/index' : path
}.json`
const { pathname: hrefPathname, query } = parse(href, true)
const { pathname: asPathname } = parse(asPath)
const route = normalizeRoute(hrefPathname)
let isDynamic = isDynamicRoute(route),
interpolatedRoute
if (isDynamic) {
const dynamicRegex = getRouteRegex(route)
const dynamicGroups = dynamicRegex.groups
const dynamicMatches =
// Try to match the dynamic route against the asPath
getRouteMatcher(dynamicRegex)(asPathname) ||
// Fall back to reading the values from the href
// TODO: should this take priority; also need to change in the router.
query
interpolatedRoute = route
if (
!Object.keys(dynamicGroups).every(param => {
let value = dynamicMatches[param]
const repeat = dynamicGroups[param].repeat
// support single-level catch-all
// TODO: more robust handling for user-error (passing `/`)
if (repeat && !Array.isArray(value)) value = [value]
return (
param in dynamicMatches &&
// Interpolate group into data URL if present
(interpolatedRoute = interpolatedRoute.replace(
`[${repeat ? '...' : ''}${param}]`,
repeat
? value.map(encodeURIComponent).join('/')
: encodeURIComponent(value)
))
)
})
) {
interpolatedRoute = '' // did not satisfy all requirements
// n.b. We ignore this error because we handle warning for this case in
// development in the `<Link>` component directly.
}
}
return isDynamic
? interpolatedRoute && getHrefForSlug(interpolatedRoute)
: getHrefForSlug(route)
}
/**
* @param {string} href the route href (file-system path)
* @param {string} asPath the URL as shown in browser (virtual path); used for dynamic routes
*/
prefetchData(href, asPath) {
const { pathname: hrefPathname } = parse(href, true)
const route = normalizeRoute(hrefPathname)
return this.promisedSsgManifest.then(
(s, _dataHref) =>
// Check if the route requires a data file
s.has(route) &&
// Try to generate data href, noop when falsy
(_dataHref = this.getDataHref(href, asPath)) &&
// noop when data has already been prefetched (dedupe)
!document.querySelector(
`link[rel="${relPrefetch}"][href^="${_dataHref}"]`
) &&
// Inject the `<link rel=prefetch>` tag for above computed `href`.
appendLink(_dataHref, relPrefetch, 'fetch')
)
}
loadPage(route) {
return this.loadPageScript(route)
}
loadPageScript(route) {
route = normalizeRoute(route)
return new Promise((resolve, reject) => {
const fire = ({ error, page, mod }) => {
this.pageRegisterEvents.off(route, fire)
delete this.loadingRoutes[route]
if (error) {
reject(error)
} else {
resolve({ page, mod })
}
}
// If there's a cached version of the page, let's use it.
const cachedPage = this.pageCache[route]
if (cachedPage) {
const { error, page, mod } = cachedPage
error ? reject(error) : resolve({ page, mod })
return
}
// Register a listener to get the page
this.pageRegisterEvents.on(route, fire)
// If the page is loading via SSR, we need to wait for it
// rather downloading it again.
if (document.querySelector(`script[data-next-page="${route}"]`)) {
return
}
if (!this.loadingRoutes[route]) {
this.loadingRoutes[route] = true
if (process.env.__NEXT_GRANULAR_CHUNKS) {
this.getDependencies(route).then(deps => {
deps.forEach(d => {
if (
/\.js$/.test(d) &&
!document.querySelector(`script[src^="${d}"]`)
) {
this.loadScript(d, route, false)
}
if (
/\.css$/.test(d) &&
!document.querySelector(`link[rel=stylesheet][href^="${d}"]`)
) {
appendLink(d, 'stylesheet').catch(() => {
// FIXME: handle failure
// Right now, this is needed to prevent an unhandled rejection.
})
}
})
this.loadRoute(route)
})
} else {
this.loadRoute(route)
}
}
})
}
loadRoute(route) {
route = normalizeRoute(route)
let scriptRoute = route === '/' ? '/index.js' : `${route}.js`
const url = `${this.assetPrefix}/_next/static/${encodeURIComponent(
this.buildId
)}/pages${encodeURI(scriptRoute)}`
this.loadScript(url, route, true)
}
loadScript(url, route, isPage) {
const script = document.createElement('script')
if (process.env.__NEXT_MODERN_BUILD && hasNoModule) {
script.type = 'module'
// Only page bundle scripts need to have .module added to url,
// dependencies already have it added during build manifest creation
if (isPage) url = url.replace(/\.js$/, '.module.js')
}
script.crossOrigin = process.crossOrigin
script.src = url
script.onerror = () => {
const error = new Error(`Error loading script ${url}`)
error.code = 'PAGE_LOAD_ERROR'
this.pageRegisterEvents.emit(route, { error })
}
document.body.appendChild(script)
}
// This method if called by the route code.
registerPage(route, regFn) {
const register = () => {
try {
const mod = regFn()
const pageData = { page: mod.default || mod, mod }
this.pageCache[route] = pageData
this.pageRegisterEvents.emit(route, pageData)
} catch (error) {
this.pageCache[route] = { error }
this.pageRegisterEvents.emit(route, { error })
}
}
if (process.env.NODE_ENV !== 'production') {
// Wait for webpack to become idle if it's not.
// More info: https://github.com/zeit/next.js/pull/1511
if (module.hot && module.hot.status() !== 'idle') {
console.log(
`Waiting for webpack to become "idle" to initialize the page: "${route}"`
)
const check = status => {
if (status === 'idle') {
module.hot.removeStatusHandler(check)
register()
}
}
module.hot.status(check)
return
}
}
register()
}
/**
* @param {string} route
* @param {boolean} [isDependency]
*/
prefetch(route, isDependency) {
// https://github.com/GoogleChromeLabs/quicklink/blob/453a661fa1fa940e2d2e044452398e38c67a98fb/src/index.mjs#L115-L118
// License: Apache 2.0
let cn
if ((cn = navigator.connection)) {
// Don't prefetch if using 2G or if Save-Data is enabled.
if (cn.saveData || /2g/.test(cn.effectiveType)) return Promise.resolve()
}
/** @type {string} */
let url
if (isDependency) {
url = route
} else {
route = normalizeRoute(route)
let scriptRoute = `${route === '/' ? '/index' : route}.js`
if (process.env.__NEXT_MODERN_BUILD && hasNoModule) {
scriptRoute = scriptRoute.replace(/\.js$/, '.module.js')
}
url = `${this.assetPrefix}/_next/static/${encodeURIComponent(
this.buildId
)}/pages${encodeURI(scriptRoute)}`
}
return Promise.all(
document.querySelector(
`link[rel="${relPrefetch}"][href^="${url}"], script[data-next-page="${route}"]`
)
? []
: [
appendLink(
url,
relPrefetch,
url.match(/\.css$/) ? 'style' : 'script'
),
process.env.__NEXT_GRANULAR_CHUNKS &&
!isDependency &&
this.getDependencies(route).then(urls =>
Promise.all(urls.map(url => this.prefetch(url, true)))
),
]
).then(
// do not return any data
() => {},
// swallow prefetch errors
() => {}
)
}
}