If the category exists it is not added

[ThinhDinh]

How do I create a custom form?

I’m just dropping this here so I have something to refer people to when they ask. This is a simple concept app (copyable), that demonstrates the following techniques: Building custom forms for adding and editing list items (as an alternative to the native forms provided by Glide) Preventing duplicate new entries using User Specific Columns and Relations Enforcing mandatory input items The use of visibility conditions and user specific booleans to control user flow There is nothing particula…

Firstly you should have a custom form, follow @Darren_Murphy 's instructions in that thread.

Assuming you store your category name in a “Category Input” variable:

• Create a relation from “Category Input” to the list of existing categories.
• Show an error message when relation is not empty (meaning that’s a duplicate).
• Only allow adding when “Category Input” is not empty and relation is empty.