Set a numeric field as a "one use only"

Hi @CalvoConBarba Oh this is an interesting use case. If you have a few designs, you could use logic jumps to check for that number and tell them if they have entered a design already. However, if it’s a lot, that might be tricky to set up. 

@mathio or @picsoung you wouldn’t happen to have any fancy workarounds for something like this by chance? 

@Liz @CalvoConBarba - if you passed the registration number in as a hidden field into the form, you would bypass the need for a question to enter the number. 

you would/should/could then connect the typeform to a google sheet and use the functions inside the google sheet to look duplicate entries and validate the timestamps .. and eliminate/ignore duplicates. 

just a thought

des

@john.desborough it has to be done on the spot, right as they are typing the number, so they are aware that the number is not correct or that their entry will not be taken into account. Just like when you try to enter a phone number with an extra number on it, or try to input 5 numbers in a number file capped at 4 numbers.

Thank anyway!

Hello @CalvoConBarba  I think you could split this into 2 typeforms:

• first form will collect the registration number
• then redirect to custom page on submit and pass the number as query parameter
• custom page will determine if the number is valid (eg. via Typeform Responses API)
• if it is valid redirect to next typeform with the rest of the questions
• if it is invalid show error message with link back to first typeeform

Would this flow work for you?

Hi @mathio, thanks for your suggestion. Problem is the first step (the one assigning a number to each participant) is not managed via typeform (and won't be), so this possible solution can not be implemented.

Ain’t a way to make a field “one use only”? could be this number field I was talking about, but it could be an email field for instance. 

I can’t find the way to avoid a user use an already used number/email/name/phone/whatever as an answer. And if someone try to enter a used number/email/name/whatever, an error message should be shown to inform the user that it is already been used, and therefore is not “valid”.

Just the way it happens if I try to enter a 5 digit number in a number field capped at 4 digits, or if I try to enter an email without extension or a phone number whit too many/little numbers in it.