[SOLVED] PWA: How to have dynamic "start

PWA: How to have dynamic "start_url" in manifest.json

I am creating a PWA and stumbled upon a problem with the "start_url" in the manifest.json file. The website which I am trying to turn into a PWA depends on query params and "start_url":"/" doesn't pick up the query params.

I tried deleting the start_url from manifest.json and that seems to allow the app to be added to home screen (on iOS) but I guess on android the install prompt won't appear without the start_url?

Anyone has experienced a similar issue?

Solution

You can create a dynamic manifest just like this: https://stackoverflow.com/a/57856162/8716572

And then you can do something like "start_url": "your-url?query=" + queryValue.

<link rel="manifest" id="my-manifest-placeholder">

var myDynamicManifest = {
  "name": "App name",
  "short_name": "short",
  "start_url": "your-url?query=" + queryValue
  "background_color": "#000000",
  "theme_color": "#0f4a73",
  "icons": [{
    "src": "icon.png",
    "sizes": "512x5126",
    "type": "image/png"
  }]
}

const stringManifest = JSON.stringify(myDynamicManifest);
const blob = new Blob([stringManifest], {type: 'application/json'});
const manifestURL = URL.createObjectURL(blob);
document.querySelector('#my-manifest-placeholder').setAttribute('href', manifestURL);

var link = document.createElement('Link');
link.rel = "manifest";
link.setAttribute('href', 'data:application/json;charset=8' + stringManifest)