Similar questions (eg. this) have already been asked and answered in negative. I'd like to if any alternatives exist.

I am developing an application where users can collaboratively edit a document. I don't want to force every user to login. I would like to allow users with a link to be able to edit a document (similar to what Google Docs allows). I was planning to share a token in the link which when presented would grant write access. I would have stored the tokens in a separate collection and matched them. But as per previous answers this is not possible and a security issue.

I don't consider it a security concern (for my purposes). The token is like a pre-shared key. Whoever presents the key is allowed access. If the owner thinks that the key is compromised, he can revoke the same. Kindly help me with a way to achieve this. I'm also curious to know how other apps like Google docs achieve this.

CodePudding user response：

As Mentioned by @Dharmaraj,
In Firebase security rules, you have 3 pieces of information, namely the path, the data and the token. Except from those three you can't pass additional information in a security rule.

Cloud Functions would be a better fit here, given the flexibility. Additionally, with Cloud Functions you'd not be forced to authenticate users, and still be able to connect to Firestore if needed.