How to check to see if a collection contains an added email?

How to check to see if a collection contains an added email?

In my app, users can register an account with their email and password. After that they are redirected to the terms of service and finally a place to create their profile. Once new users create an account they get a reward for being a new user. The reward being credits.

In the app you can either watch ads for free credits or purchase them, the only other way being if you are a new user in which you would get 25 free credits.

An issue that might arise is that the user could delete their account, re-register, and then get the same more credits for free.

(If the user uses up their free credits, they could just delete their account, re-register, and get even more free credits which are only meant for new users.)

To prevent users from getting the free credits, I have added their email to a collection called, “Free Credits (New Users Only)”. The users who have their email added to the collection can still sign up however, the only difference is they will not get the free credits.

Here are some of the issues I am facing:

  • In the image below I was able to add an email by creating a new item in the collection “Free Credits (New Users Only)” however, before that happens, I am trying to check if collection already contains the email. Where it says “Empty” it will only let me choose from a drop down option, not the user’s email so it ends up still adding the email anyways. (I have tested this with relationships between the collection and the user as well all with no luck.

  • The last image is not letting me pick the user email.
    image

For the “Will be visible if…”
I chose All data within the collection, "free credits (new user only)
and I chose “Does not contain”. For the last part that says “Empty” I would like to put
“Logged In User > Email” and have it not give the credits since the user’s email is already in the collection of those who had already gotten the free credits.

Is this at all possible?

Welcome to the community @Tadachii

Use a count instead.

Sometimes visible if All free credits count with a custom filter where email is equal to logged-in user email is not equal to 0. This will not allow the free credits to be applied to the user if the user has already received the free credits.

Add a 2nd button with the opposite filter: Sometimes visible if All free credits count with a custom filter where email is equal to logged-in user email is equal to 0. This will give free credits to the user if they do not exist.