I created a collection type which had white spaces in API ID fields. Strapi showed no validation error, but I couldn't save the collection and stuck at that step forever, unless I delete the collection and re-create it.

I think, Strapi should, at least, has a white spaces check for API ID fields.

Thanks,

This will be Great Feature. :-)

Yeah it would be really good to be able to write custom field and entity level validations that are displayed in the UI and returned through API.

Some validation examples:

* I want to make sure that start date is before end date

* I want to make sure that a field is filled out if another checkbox is checked

* I want to make sure that a number is a multiple of 10

* ...