This plugin adds silent duplicate detection to the popular Gravity Forms WordPress plugin. The goal is to prevent Gravity Forms from creating multiple entries when an impatient user double-, triple, or full-on secret-combo-move-clicks his/her mouse when submitting a form. No modifications to your forms is necessary, it just works.
How does it work?
The plugin prevents duplicate submissions in two ways: first, a small bit of JavaScript is loaded into the page that disables the submit button(s) on form submit. Second, the plugin creates a cryptographic hash of the form data upon submission. This unique hash is compared to a hash stored in a PHP session (if available) and, if a matching hash is found, the form data is altered to simulate a failing honeypot condition. Like with all failed honeypots, Gravity Forms will skip saving the data or sending any notifications but the form will appear (to the user) to have been submitted successfully.
Plugin development can be tracked on the project’s Github Page: https://github.com/buckii/gravity-forms-duplicate-prevention