Gravity Forms shuffle fields on current page only

gf_page_fields_shuffle.php

<?php 

/**
 * Gravity Forms Shuffle fields on current page.
 * To impliment add this to your functions.php file
 * adding the form id will isolate the filter e.g. add_filter( 'gform_pre_render_5', 'randomize_field_order');
 */


add_filter( 'gform_pre_render', 'randomize_field_order'); 

function randomize_field_order ( $form ) {

  $current_page = GFFormDisplay::get_current_page( $form['id'] );
  $fields = $form[fields];

	function filter_by_key($array, $member, $value, $member2, $value2) {
	   $filtered = array();
	   foreach($array as $k => $v) {
	      if($v->$member == $value && $v->$member2 != $value2)
	       	 array_push($filtered, $k);
	   }
	   return $filtered;
	}

	$pageFields = filter_by_key($form['fields'],'pageNumber',$current_page,'type','page');

	function swap(&$a, &$b) { list($a, $b) = array($b, $a); }
	for($i = 0; $i < count($pageFields); $i++) {
	   $j = rand(1, count($pageFields)) - 1;
	   swap($fields[$pageFields[$i]], $fields[$pageFields[$j]]);
	}

	$form[fields] = $fields;

	return $form;
}

?>

Thanks for this.

Just to let you know, I had to put quotation marks between "fields", on lines 15 and 34:

$form['fields'] = $fields;

Cheers