hedgedoc/src/service-worker.ts
Philip Molares eba59ae622
better linting (#72)
Improve linting and fix linting errors

Signed-off-by: Philip Molares <philip.molares@udo.edu>
Signed-off-by: Tilman Vatteroth <tilman.vatteroth@tu-dortmund.de>
2020-05-27 15:43:28 +02:00

138 lines
4.9 KiB
TypeScript

// This optional code is used to register a service worker.
// register() is not called by default.
// This lets the app load faster on subsequent visits in production, and gives
// it offline capabilities. However, it also means that developers (and users)
// will only see deployed updates on subsequent visits to a page, after all the
// existing tabs open on the page have been closed, since previously cached
// resources are updated in the background.
// To learn more about the benefits of this model and instructions on how to
// opt-in, read https://bit.ly/CRA-PWA
const isLocalhost = Boolean(
window.location.hostname === 'localhost' ||
// [::1] is the IPv6 localhost address.
window.location.hostname === '[::1]' ||
// 127.0.0.0/8 are considered localhost for IPv4.
new RegExp(/^127(?:\.(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)){3}$/).exec(window.location.hostname)
)
type Config = {
onSuccess?: (registration: ServiceWorkerRegistration) => void;
onUpdate?: (registration: ServiceWorkerRegistration) => void;
};
export function register (config?: Config):void {
if (process.env.NODE_ENV === 'production' && 'serviceWorker' in navigator) {
// The URL constructor is available in all browsers that support SW.
const publicUrl = new URL(
process.env.PUBLIC_URL,
window.location.href
)
if (publicUrl.origin !== window.location.origin) {
// Our service worker won't work if PUBLIC_URL is on a different origin
// from what our page is served on. This might happen if a CDN is used to
// serve assets; see https://github.com/facebook/create-react-app/issues/2374
return
}
window.addEventListener('load', () => {
const swUrl = `${process.env.PUBLIC_URL}/service-worker.js`
if (isLocalhost) {
// This is running on localhost. Let's check if a service worker still exists or not.
checkValidServiceWorker(swUrl, config)
} else {
// Is not localhost. Just register service worker
registerValidSW(swUrl, config)
}
})
}
}
function registerValidSW (swUrl: string, config?: Config) {
navigator.serviceWorker
.register(swUrl)
.then(registration => {
registration.onupdatefound = () => {
const installingWorker = registration.installing
if (installingWorker == null) {
return
}
installingWorker.onstatechange = () => {
if (installingWorker.state === 'installed') {
if (navigator.serviceWorker.controller) {
// At this point, the updated precached content has been fetched,
// but the previous service worker will still serve the older
// content until all client tabs are closed.
console.log(
'New content is available and will be used when all ' +
'tabs for this page are closed. See https://bit.ly/CRA-PWA.'
)
// Execute callback
if (config && config.onUpdate) {
config.onUpdate(registration)
}
} else {
// At this point, everything has been precached.
// It's the perfect time to display a
// "Content is cached for offline use." message.
console.log('Content is cached for offline use.')
// Execute callback
if (config && config.onSuccess) {
config.onSuccess(registration)
}
}
}
}
}
})
.catch(error => {
console.error('Error during service worker registration:', error)
})
}
function checkValidServiceWorker (swUrl: string, config?: Config) {
// Check if the service worker can be found. If it can't reload the page.
fetch(swUrl, {
headers: { 'Service-Worker': 'script' }
})
.then(response => {
// Ensure service worker exists, and that we really are getting a JS file.
const contentType = response.headers.get('content-type')
if (
response.status === 404 ||
(contentType != null && contentType.indexOf('javascript') === -1)
) {
// No service worker found. Probably a different app. Reload the page.
navigator.serviceWorker.ready.then(registration => {
return registration.unregister().then(() => {
window.location.reload()
})
}).catch(() => console.log('Service worker not ready'))
} else {
// Service worker found. Proceed as normal.
registerValidSW(swUrl, config)
}
})
.catch(() => {
console.log(
'No internet connection found. App is running in offline mode.'
)
})
}
export function unregister ():void {
if ('serviceWorker' in navigator) {
navigator.serviceWorker.ready
.then(registration => {
return registration.unregister()
})
.catch((error:Error) => {
console.error(error.message)
})
}
}