Drop.dowm menu: values available based on values already selected

[Pascal_Vallet]

I have designed a simple table for the dismissal in our school.
On one tab I have “Today dismissal”
On the second tab I have 25 inputs : each line has a homeroom name and an image attached to the homeroom. The second tab is also attached to the first one.
I have then from tab one created a form where we can select the homeroom with a drop down menu.
I have also a view that shows ONLY the new entries based on a simple criteria: the date (today). I am then sharing this view so the security guard a the school gate can see from his iPad set up to refresh every 5 seconds the homerooms ready for dismissal and call the parents in.

What i would like to do:
If i sleeve homeroom x today, homeroom x is not available anymore from the drop down menu just for today. So i can see in my drop down when all the 25 classes have already been selected.
The following day, because it’s day+1, all the 25 homerooms are still available in the drop down menu.

How can I do this?

[Justin_Barrett]

If I’m reading your description correctly, the view shared with security only shows the newly-linked records from the second table. If that’s correct, it sounds like what you need is a view that’s the opposite of the one that you’re sharing with security, only displaying the homerooms that are not linked.

With that view created, you can set the form to only allow records to be selected from that new view. Read more about this here:

Airtable Support

Limiting linked record selection to a view

You may have seen the option to "Limit record selection to a view" in the field customization window of a linked record field. This article will walk you through the ins and outs of this feature. ...

That would give you a shrinking list to choose from as you select more homerooms.

FWIW, you don’t need a form to do this. You can set this up directly in a grid view. Submitting and refreshing the form feels like overkill for a situation like this.

[Pascal_Vallet]

Thanks I will look into it.

[Pascal_Vallet]

The reason why I need a form is because I want my teachers to be the one when walking out to select their homeroom but i don’t want to give access to the air table database directly.

[Justin_Barrett]

Thanks for the clarification. In that case, the form behavior will work. When the teacher submits the form, their homeroom will appear on the list for security, and won’t appear on the list when other teachers open the same form.

Note that if a teacher leaves the form open for a while before using it, the list that they see will still include homerooms for teachers who have already submitted. The form view isn’t a live look at the data, so that view-based filter will only be based on submissions that took place up to the time that the form was opened, but not after that. In that light, I suggest pointing this out to the teachers, and encouraging them to wait to open the form until they’re ready to submit for dismissal.