从 flutter 中的电话号码获取用户 ID

Question

in the app, which logs the user in only through phone authentication. now the question is can I get the user id from his phone number(not the user id of the current user though). I have the access to other users phone number in the app, and I want to get their id for further use. is it possible in flutter with firebase at the backend?

Answer 1

Looking up the UID for a user based on either phone number or email address is considered a sensitive operation. For this reason such operations are only available in the Admin SDKs, which are designed to be used in trusted environments, such as your development machine, a server you control, or Cloud Functions. For more on these, see the bottom two code samples in looking up user data in the documentation.

If you want to perform such operations from your client-side code, your two main options are:

1. Store the required mapping in a cloud-hosted database, such Firebase's Realtime Database or Firestore, as Huthaifa also answered .

2. Create your own custom API on a server or Cloud Functions where you lookup the user through the Admin SDK. Your client-side application code can then call this custom API.

In both of these cases you are in full control of what data you share, and how you secure access.

Answer 2

Sure you can, there are multiple approaches for this, if you post your structure for the user model, or how you are storing them in firebase.

You can run a simple Firebase query like this example: FirebaseFirestore.instance.collection('users').where('phoneNumber', isEqualTo: thePhonenumberOftheuserYouwant2GetUIDfor).get()

You can also store the available\accessible contacts for every user in their user document, and when your user logs in, it'll fetch all their allowed user numbers.

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