How to prevent form submission based on submitted values

Created by Phil Kurth, Modified on Mon, 04 Jul 2022 at 02:02 PM by Phil Kurth

If you need to stop a form from being submitted based on the submitted values, you can do so as follows:

// Hook into the before_submission action and call wp_die() if the submission has a value we don't want to be submitted.
add_action( 'af/form/before_submission', function ( $form, $fields, $args ) {
  // Only run on a specific form.
  if ( $form['key'] !== 'YOUR_FORM_KEY_HERE' ) {
    return;
  }

  $message = af_get_field( 'YOUR_FIELD_NAME_HERE' );
  if ( $message === 'some unwanted text' ) {
    af_add_submission_error( 'This is a custom error message' );
  }

}, 10, 3 );

By using the af_add_submission_error() function, you will trigger a notice in the UI above the form letting the user know that there was a problem submitting the form.