[Tip] Custom valuelists and check/radios fields

This one really set my brain to work (I know I know... what brain?)

This is the case: I created a check field and attached a custom valuelist. Running the application and checking a box worked like I expected it to. The unfortunate thing though was that I couldn't uncheck either of the checkboxes anymore. I could check more, I could one (or the other) but could simply not uncheck all...

I knew from creating a 'normal' valuelist that I could check 'allow empty fields'. In the case of that 'normal' valuelist this creates an empty entry and would make it possible to archieve what I wanted. But not with a custom valuelist. It simply won't add an empty entry and thus doesn't solve the problem.

Here is what to do: when you create the array that you need for your custom valuelist you have to start that array with an empty value AND check the box 'allow empty values'. These two together will do the trick. Bare in mind. You have to do both and the empty entry has to be the first value in the array!

Off course the same goes for radios.