Firebase Extension for URL Shortening: How to put in Firestore path to location of URL?

Question

I want to use a Firebase extension called "URL Shortening" (URL shortening) and one of the questions in the installation guide states: "What is the path to the collection that contains the URLs that you want to shorten?"

How do I put in the path if the URL I want to shorten is located here (in yellow)?

Answer 1

I don't think it is currently possible for Extensions to specify a subcollection, see https://github.com/firebase/extensions/issues/352.

However it seems that a release which supports collectionGroup queries is on its way (see https://github.com/firebase/extensions/pull/354).

Answer 2

Configuration on Firebase Extensions can use wildcard paths for collections.

Setting your collection path config to:

users/{id}/posts

will translate any documents under a posts sub-collection that exists under a users collection document.