Input Mask Problem

Hi, I created a string that needs to be filled for credit card. Because I want that attribute to be filled with numbers, I created an input mask that has 8 digits (such as 99999999). Also, I want users to enter exactly 8 digits, not 2 or 5 or 6 digits. Therefore, I created a validation like length($Pay/Card) != 8. It gives an validation message, otherwise continue. But because I created an input mask, even if users enter 1 or 2 digit, validation perceives it as if 8 digits are filled. Can you help me find the answer?
1 answers

I think isMatch($Pay/Card ,'\d{8}') = true works for you. You can write it in decision and if it is true, validation will continue, otherwise you can return warning message.