Guide: How to Add Headers to HTTP Request (send by Plyr)

[KangHidro]

Maybe you will encountered the case that Video need Auth Token to fetch, so I hope my guide may help you a litle bit! Thanks to @Ashesh3! https://github.com/sampotts/plyr/issues/1312#issuecomment-677267757

1. Create service worker JS file (e.g. sw.js), place it in some where (e.g. src/assets/js/service-worker/). File content is:

let domainInclude = ''; // Recieve from Component
let authToken = ''; // Recieve from Component

self.addEventListener('install', event => {
  const params = new URL(location);
  domainInclude = params.searchParams.get('include');
  authToken = params.searchParams.get('token');
  const installCompleted = Promise.resolve()
    .then(() => {});
  event.waitUntil(installCompleted);
});

self.addEventListener('activate', event => {
  event.waitUntil(
    self.clients.claim(),
    caches.keys().then((cacheNames) => {
        return Promise.all(
            cacheNames.map((cache) => {
                if (cache !== cacheName) {
                    return caches.delete(cache);
                }
            })
        );
    }));
});

// This function is implement from the guide of @Ashesh3
self.addEventListener('fetch', event => {
  if (event.request.url.includes(domainInclude)) {
    event.respondWith(customHeaderRequestFetch(event));
  }
});

function customHeaderRequestFetch(event) {
  const newRequest = new Request(event.request, {
    mode: "cors",
    credentials: "omit",
    //also supports partial content (seeking)
    headers: {
      range:
        event.request.headers.get("range") != undefined
          ? event.request.headers.get("range")
          : "0-",
      Authorization: authToken
    }
  });
  return fetch(newRequest);
}

2. Edit file angular.json: Path: projects > <your-pj-name> > architect > build > options > assets:

"assets": [
   ..........
  {
      "glob": "**/*",
      "input": "src/assets/js/service-worker/",
      "output": "/"
   }
   ..........
]

3. Go to your Component, where you want to start Service Worker:

ngOnInit() {
   if ('serviceWorker' in navigator) { // Make sure browser support Service Worker
      navigator.serviceWorker.register(`/sw.js?include=${encodeURIComponent('<URL_MATCHING>')}&token=${<YOUR_TOKEN>}`, {
        scope: '<SCOPE>'
      })
        .then(registration => registration.unregister());
        // SW unregistered still working till page reload, so don't worry.
        // But if you don't unregister here, Component may get stuck when you reload page,
        // because old SW is fetching video and not done yet.
        // In this case, If you stop playing video a while, page can be reload.
    } else {
      window.alert('Browser not support Service Worker.');
    }
}

Note:

• <URL_MATCHING>: Send to sw.js, using to check matching the endpoint you need to add Headers. E.g. /api/video/: If Request URL include /api/video/ then sw.js will adding Headers to the request. (http://backend.local/api/video/aaaaa)
• <YOUR_TOKEN>: Token send to sw.js for attach to Headers.
• <SCOPE>: Router link where sw.js will working, e.g. /view-video/ (http://localhost:4200/view-video/aaaaa)

P/s: I re-open this issues because Github hide closed issues automatically, so keep this open will make others easy to find :D

[Ashesh3]

Nice guide! I'm glad we were able to solve this problem.

[Suroor-Ahmmad]

@KangHidro I tried to implement this and works fine, but I wonder why it doesn't work in some cases. Sometimes token is not getting attached in the request, even though I can see SW running, I see only this specific request is not fetched by the SW, I have to refresh the page to get it working, and also if I unregister SW, sometimes I get error DOMException: Only the active worker can claim clients.. any help/suggestion will be appreciated (Ps. I have very less idea about service-workers)

[KangHidro]

@Suroor-Ahmmad I'm also new and have no idea about SW,

Sometimes token is not getting attached in the request, even though I can see SW running

You can modify sw.js for check workflow of codes:

self.addEventListener('fetch', event => {
  console.log('Request had addEventListener fetch'); //////////////////////////
  if (event.request.url.includes(domainInclude)) {
    console.log('Request had correct domain'); //////////////////////////
    event.respondWith(customHeaderRequestFetch(event));
  }
});

function customHeaderRequestFetch(event) {
  console.log('Request go into customHeaderRequestFetch'); //////////////////////////
  const newRequest = new Request(event.request, {

If the error frequency is low as acceptable level, I think refresh the page is the most optimal way.

-- If I got the same error with you (and I can fix it), I will let you know :D