For those of you using WordPress, GravityForms can be a real godsend. GravityForms is a premium plugin that makes it extremely simple to create forms on your website. However, there are a few features that aren’t quite built out the way they probably should be, yet.
One of those features is the ability to stop people from submitting forms with duplicate values. While this feature is extremely useful the way it’s currently implemented when it comes to duplicate entries for people’s names, email addresses, etc., it’s not overly useful when it comes to select elements, radio buttons and checkboxes. As it is currently implemented, all of the options are still available for the user to select when filling out the form, but when they submit the form, they get an error message indicating the option has already been selected.
With the use of some GravityForms filters, though, you can make things slightly more usable.