Post Payment Gravity Forms

functions.php

/**
 * Update puppy reservation status after payment is received.
 *
 * @link https://docs.gravityforms.com/gform_after_submission/
 *
 */
add_action( 'gform_post_payment_completed', 'wd_gform_submission_updates', 10, 2 );
function wd_gform_submission_updates( $entry, $payment_id ) {

	// Get form title of form that was submitted.
	$form = GFAPI::get_form( $entry['form_id'] );
	$form_title = $form['title'];

	// Update puppy reserved status when deposit is paid.
	if( $form_title == 'Puppy Payments' ) {

		// Get form data.
		$puppy_id        = (int) rgar( $entry, '9' );
		$user_first_name = rgar( $entry, '2' );
		$user_last_name  = rgar( $entry, '3' );
		$user_name       = $user_first_name . ' ' . $user_last_name;

		// Update availability and reserved for fields.
		if ( ! empty( $puppy_id ) ) {
			update_field( 'availability', 'reserved', $puppy_id );
			update_field( 'reserved_for', $user_name, $puppy_id );

			// Flush out page cache to show proper status (WP Rocket).
			if ( function_exists( 'rocket_clean_post' ) ) {
				rocket_clean_post( $puppy_id );
			}
		}
	}
}