What if an app changes their manifest URL?

[alancutter]

The web-app-origin-association file currently identifies other PWAs via their manifest URL:

{
    "web_apps": [
        {
            "manifest": "https://partnerapp.com/manifest.json",
            "details": {
                "paths": [
                    "/public/data/*"
                ]
            }
        }
    ]
}

There is active discussion around speccing an "app ID" with the intention of allowing sites to update their start_url and manifest URLs.
w3c/manifest#586
In this discussion it mentions sites using versioned manifest URLs. This proposed API would be incompatible with that practice.

[dmurph]

Explainer & suggested solution from us is here at this explainer:
https://github.com/philloooo/pwa-unique-id/blob/main/explainer.md

[LuHuangMSFT]

If I understand the current implementation of id correctly, the global id is either the start URL, or the start URL's origin+the specified id from the manifest id field.

This allows a URL analogous to our current use of the manifest URL to uniquely identify a PWA.

The proposed change that would resolve this issue is to replace manifest with unique_id, which is itself a URL. During validation, instead of searching WAOA for the URL where an app's manifest was downloaded, search for the calculated "global id" of the app.

New example:

{
    "web_apps": [
        {
            "unique_id": "https://partnerapp.com/manifest.json",
            "details": {
                "paths": [
                    "/public/data/*"
                ]
            }
        }
    ]
}