Add referring site to Gravity Forms

rkv_referr_source

function rkv_referr_source() { ?>

<script type="text/javascript">

// build function for cookie process
function rkv_grab_cookie() {
	
	// check document referrer
	if (document.referrer !== '')
		var rkv_val	= document.referrer;
	else
		var rkv_val	= 'unknown';

	// set cookie variables and clean URL
	var rkv_name	= 'rkv_ref';
	var rkv_str		= rkv_name + '=' + encodeURI(rkv_val);
	
	// check for cookie
    var rkv_chk	= document.cookie.match('(^|;) ?' + rkv_name + '=([^;]*)(;|$)');

	// add the cookie if none exists	
    if (!rkv_chk)
		document.cookie = rkv_str;
}

// call cookie function
rkv_grab_cookie();

</script>

<?php }

add_action('wp_head', 'rkv_referr_source');

rkv_referrer_formdata

function rkv_referrer_formdata($data) {

	// grab cookie if it exists
    $ref_source  = $_COOKIE['rkv_ref'];

   	// add cookie to form
    $data['notification']['message'] .= "\r\nReferrer Source:\r\n".$ref_source;

	// return referrer source and add to form
	return $data;
}

add_filter('gform_pre_submission_filter', 'rkv_referrer_formdata');