How to generate and place a blob file on a relative path?

Question

While building the "Add to Homescreen" feature on a relative URL, I am generating my manifest.json dynamically and placing it via creating a Blob URL and adding it to the href attribute of the link[rel="manifest"] .

The place where I am stuck is, my generated manifest URL points to something like: https://example.com/jbskdjcs9987r38943nsmd instead what I want is: https://example.com/pwa/jbskdjcs9987r38943nsmd which is nothing but wanting the blob file to be placed on a relative URL.

Below is the example of how I am generating a blob file:

 let myManifest = { "name": "Example PWA", "short_name": "PWA", "description": "Example PWA", "start_url": ".", "display": "standalone", "theme_color": "#3f51b5", "background_color": "#3f51b5", "icons": [ { "src": "images/android-chrome-192x192.png", "sizes": "192x192", "type": "image/png" }, { "src": "images/android-chrome-512x512.png", "sizes": "512x512", "type": "image/png" } ] } const stringManifest = JSON.stringify(myManifest); const blob = new Blob([stringManifest], {type: 'application/json'}); const manifestURL = URL.createObjectURL(blob); console.log(manifestURL); //document.getElementById('my-manifest-placeholder').setAttribute('href', manifestURL);

I thought of doing something like:

 const myURL = new URL('/pwa/','https://example.com'); const manifestURL = myURL.createObjectURL(blob);

But this does not work as createObjectURL is a URL's Static Method.

Any suggestion that would let me generate and place my manifest.json file dynamically on a relative URL would be appreciated.

Thanks in advance.

Answer 1

Regarding the relative URL, I couldn't figure out a way to dynamically place the blob file on a relative URL but worked around using Data URL approach.

Below is an example of the Data URL approach:

const stringManifest = JSON.stringify(myDynamicManifest);
const blob = new Blob([stringManifest], {type: 'application/json'});
// const manifestURL = URL.createObjectURL(blob);
let reader = new FileReader();
reader.readAsDataURL(blob);
reader.onload = function(){
  document.getElementById('my-manifest-placeholder').setAttribute('href', reader.result);
}