14 July 2008 | General, PHP, Web Development, Zend Framework | Chris

Back a few weeks ago I came across a very handy Zend Framework Helper for tracking a user’s browsing history(here).  I was needing something very similar for a project I was working on, actually I need it for most projects I work on.  While implementing it I noticed there were some things that I wanted to modify in order to get the true functionality I needed.

The modifications were pretty basic in that the code was tracking ALL requests and there are a few requests that I did not want to track(namely Ajax and page reloads).  By not tracking these requests I feel I get a much more accurate representation of the path the user is following through the application.  The one thing I am still yet to conquer is how to find out if a requests is triggering a 404 page and if so to not track it.  I’m not sure that it is even possible because of when the helper is triggered but I haven’t delved very deep either(just something I want to put in at some point but if you know how let me know in the comments).So without further ado the code:

<?php
Zend_Loader::loadClass('Zend_Controller_Action_Helper_Abstract');
Zend_Loader::loadClass('Zend_Controller_Action_HelperBroker');
Zend_Loader::loadClass('Zend_Session_Namespace');
/**
* This helper tracks the user's browsing history
*
* @copyright 2008 Jani Hartikainen <www.codeutopia.net>
* @author Jani Hartikainen <firstname at codeutopia net>
* @author Chris Antoine <chris@spinweb.net>(Modifications)
*/
class SoulOpinion_Action_Helper_History extends Zend_Controller_Action_Helper_Abstract
{
/**
* @var Zend_Session_Namespace
*/
private $_namespace;

/**
* How many history URLs to track?
*
* @var int
*/
private $_trackAmount = 0;

/**
* Track Ajax Requests?
*
* @var int
*/
private $_ajax = 0;

/**
* Current URL
*
* @var string
*/
private $_currentUrl = null;

/**
* @param int $trackAmount [optional] How many history URLs to track
*/
public function __construct($trackAmount = 5)
{
$this->setTrackAmount($trackAmount);

$this->_initSession();
}

/**
* Initialize the history from session
*/
private function _initSession()
{
$this->_namespace = new Zend_Session_Namespace('Zend_Controller_Action_Helper_History');

// Break out if we don't want to track the request
if ($this->trackableRequest() == false) {
return true;
}

if (!is_array($this->_namespace->history)) {
$this->_namespace->history = array();

if(!empty($_SERVER['HTTP_REFERER'])) {
array_unshift($this->_namespace->history, $_SERVER['HTTP_REFERER']);
}
} else {
array_splice($this->_namespace->history, $this->_trackAmount);
}
}

public function preDispatch()
{
$urlHelper = Zend_Controller_Action_HelperBroker::getStaticHelper('Url');
$this->_currentUrl = $urlHelper->url();

// Break out if we don't want to track the request
if ($this->trackableRequest() == false) {
return true;
}

if (!is_array($this->_namespace->history)) {
$this->_namespace->history = array();
}

array_unshift($this->_namespace->history, $this->_currentUrl);
}

/**
* Set how many history URLs to track
*
* @param int $trackAmount
*/
public function setTrackAmount($trackAmount)
{
$this->_trackAmount = $trackAmount;
}

/**
* Redirects the browser back in history
*
* @param int $amount How many URLs to go back
*/
public function goBack($amount = 1)
{
Zend_Controller_Action_HelperBroker::getStaticHelper('Redirector')
->setPrependBase(false)
->gotoUrl($this->_namespace->history[$amount]);
}

/**
* Returns an URL from history
*
* @param int $amount How many URLs to go back
* @return string
*/
public function getPreviousUrl($amount = 1)
{
return $this->_namespace->history[$amount];
}

/**
* Return all previous URLs
*
* @return array
*/
public function getArray()
{
return $this->_namespace->history;
}

public function getName()
{
return 'History';
}

/**
* Validate that we want to track the request
*
* @return Boolean
*/
private function trackableRequest()
{
// Decide whether or not we should track Ajax Requests
if ($this->_ajax == 0) {
Zend_Loader::loadClass('Zend_Controller_Request_Http');
$request = new Zend_Controller_Request_Http();

if ($request->isXmlHttpRequest()) {
return false;
}
}

// Now we are going to verify the user didn't just reload the page or click the same link.
// No reason to track page reloads.
if ($this->_currentUrl == $this->_namespace->history[0]) {
return false;
}

// Need to come up with a way to check for a 404 error so we don't track bad requests.

return true;
}
}