MemberPress: Require Coupon Code for Specific Free Memberships

// CHANGE this array - should be a comma separated list of Membership ID's to apply the signup codes to

$GLOBALS['free_memberships_require_coupon'] = array(123);

function make_coupon_mandatory_free_membership($errors) {

	if(!isset($_POST['mepr_coupon_code']) || trim($_POST['mepr_coupon_code']) == '' && in_array($_POST['mepr_product_id'], $GLOBALS['free_memberships_require_coupon'])) {

		$errors[] = 'A valid coupon code is required to sign up for this membership.';

	}

	return $errors;

}

add_filter('mepr-validate-signup', 'make_coupon_mandatory_free_membership');

// Needed to show hidden coupon field on free memberships

function show_coupon_field_free_membership() {

	$is_free_membership = false;

	foreach($GLOBALS['free_memberships_require_coupon'] as $membership_id) {

		if(is_single($membership_id)) {

			$is_free_membership = true;

		}

	}

	if($is_free_membership):

		?>

		<script type="text/javascript">

			(function($) {

				$(document).ready(function() {

					// Not needed for free memberships as coupon field is hidden and no link to enable it

					// Uncomment for non-free memberships though

					// $('.mepr-signup-form .have-coupon-link').trigger('click');

					$('input[name="mepr_coupon_code"]').attr("type", "text");

					$('input[name="mepr_coupon_code"]').before('<label>Coupon Code (Required)*</label>');

				});

			})(jQuery);

		</script>

		<?php

	endif;

}

add_action('wp_footer', 'show_coupon_field_free_membership');