Determina 'origin_slug' nos formulários do Gravity Forms

gravity_forms_origin_slug.php

<?php
add_filter( 'gform_pre_render', 'populate_referral_url' );
add_filter( 'gform_pre_validation', 'populate_referral_url' );
add_filter( 'gform_pre_submission_filter', 'populate_referral_url' );
add_filter( 'gform_admin_pre_render', 'populate_referral_url' );

function populate_referral_url( $form ){
	if ( $form['id'] != 2 && $form['id'] != 3) {
		return $form;
    }
	
	// get origin URL
   	$origin_url = $_SERVER['HTTP_REFERER'];
	
	// parse URL
	$origin_slug = parse_url($origin_url);
	
	// get path of URL and remove bars
	$path = trim($origin_slug["path"], '/');
	
	foreach($form["fields"] as &$field)
 		if($field->cssClass == 'origin_slug') {
			$field->defaultValue = $path === '' ? 'home' : $path;
 		}	
	return $form;
}