If an item exists on a `many: false` relationship, hide the create button, or rename it to something else

[hypeJunction]

Bug report

Describe the bug

A relationship field with many: false provides an option to Create a new entry, event though one already exists.

[bladey]

Hey @hypeJunction,

In this case, if you click on Create Web Meta it will create another item and set it as the linked item, unlinking the original (if one was set as per your example).

In the examples-staging/basic example we have phone numbers, if I set this to many: false, and create another phone number it's in place, the item remains but only links the user to the latest one we created.

Example:

However I can see the argument that it might not appear that way, and if an item exists on a many: false relationship that we hide the create button, or rename it to something else.