Button only visible when rating scales are filled in

Flippy

Hello guys,

again I need help with my inline script code.

I have created a form with 4 rating scales on it. When all 4 rating scales are filled in, a 'Next' button has to appear.
When one of these rating scales are not filled in, there should be no possibility to move on to the next page.

How is it possible to check if all 4 rating scales are filled in on an event base(mouse click) and then to make the button visible while the form is presented? It is not an option to reload the whole form because of some randomization I have to do on it.

Thanks for your ideas and input

Flippy

Ok I got it myself
For anyone with the same problem as me, here is my solution:
Execute the form
"while True" loop
if one of the response variables you get from the rating scales are empty execute the form again
else break the loop

Here is the python code for an inline script:

form = widgets.form(self.experiment, cols=[1,1,1,1,1,1], rows=[3,1,3,1,1], margins=(10,10,10,10))
button = widgets.button(form, text='Next')
form.set_widget(button, (4,4), colspan=1)
form._exec()
while True:
    if var.response1 == None or var.response2 == None or var.response3 == None or var.response4 == None:
        form._exec()
    else:
        break