A new knowledge base article has been published on our support portal.
In this scenario we need to validate that the user enters exactly four digits for a credit card field or leaves it blank. The validation needs to execute when the user tabs out of the credit card field (i.e. Client-Side) and it also needs to execute on Save (i.e. Server-Side.)
One thing that makes this validation tricky is that the field storing the credit card data was setup as a string field so we can’t rely on the CRM validation for whole numbers.
Below is an example of the message the user would see when tabbing out of the Credit Card 4 Digits field with an invalid last 4 digits.