Class to create a GA email tracking pixel

emailTrack.php

<?php

/**
 * @file Class to create a Google Analytics email tracking pixel.
 *       It will be used to integrate our html email generator "Fabricador"
 */

class EmailTrack {
    
    public $GAtrackingID = 'UA-7467053-1'; // Replace by your Google Analytics Tracking ID
    public $supporterID = '{user_data~supporter_id}'; // Engaging Networks tag to insert user ID. Shoud be a tag that's unique for every user. You can't use information that allows others to identify the user. (No phone, email, full name, id number...)
    
    public $medium = 'email'; // Utm medium
    
    public $category = 'email'; // Analytics event category
    public $action = 'open'; // Analytics event action
    
    /**
     * Creates a new email pixel with all defaults
     * @private
     * @param string $subject Subject of the email
     * @param string $source  Utm source that identifies the segment you are emailing too
     * @param string $campaign Utm campaign that identifies the main campaign of the email
     */
    function __construct( $subject = 'EmptySubject', $source = 'DefaultSource', $campaign = 'DefaultCampaign') {
        $this->subject = $subject;
        $this->source = $source;
        $this->campaign = $campaign;
    }
    
    /**
     * Calculates the path from some object proprieties
     * @return string Path string
     */
    private function getPath() {
        return '%2F' . urlencode($this->source) . '%2F' . urlencode($this->campaign) .'%2F' . urlencode($this->subject);
    }
    
    /**
     * Returns a pageview URL pixel
     * @return string URL of the pixel
     */
    public function getPageviewUrl () {
        $urlPixel = 'https://www.google-analytics.com/collect?v=1'
        . '&tid=' . $this->GAtrackingID
        . '&t=pageview'
        . '&dp=' . $this->getPath()
        . '&dt=' . urlencode($this->subject)
        . '&cn=' . urlencode($this->campaign)
        . '&cs=' . urlencode($this->source)
        . '&cm=' . urlencode($this->medium)
        . '&cc=' . urlencode($this->subject)
        . '&cid=' . $this->supporterID; 
        return $urlPixel;
    }
    
    /**
     * Returns an event URL pixel
     * @return string URL of the pixel
     */
    public function getEventUrl () {
        $urlPixel = 'https://www.google-analytics.com/collect?v=1'
        . '&tid=' . $this->GAtrackingID
        . '&t=event'
        . '&ec=' . urlencode($this->category)
        . '&ea=' . urlencode($this->action)
        . '&cn=' . urlencode($this->campaign)
        . '&cs=' . urlencode($this->source)
        . '&cm=' . urlencode($this->medium)
        . '&cc=' . urlencode($this->subject)
        . '&cid=' . $this->supporterID;
        return $urlPixel;
    }
    
    /**
     * Transforms an url segment in an image tag
     * @param  string $urlPixel URL of the pixel
     * @return string Html image tag to put in the email
     */
    public static function getImageTag ($urlPixel) {
        return '<img src="' . $urlPixel . '" />';
    }
    
    /**
     * Transforms an url segment in an image tag, to display the html
     * @param  string $urlPixel URL of the pixel
     * @return string Html image tag to put in the email
     */
    public static function getHtmlImageTag ($urlPixel) {
        return '&lt;img src="' . $urlPixel . '" /&gt;';
    }

}

?>

test.php

<?php
require_once('emailTrack.php');

// INSTANTIATE PAGEVIEW TACKER
// Email subject, traffic source (utm), campaign (utm)
// For the Spanish office traffic source can be newsletter-socios or newsletter-leads
$myPageviewTracker = new EmailTrack('Add email subject here', 'newsletter-socios', 'Campaign'); 

// Get a URL with the pageview type
$urlPixelPageview = $myPageviewTracker->getPageviewUrl();

// Get a visible html tag with the URL
$imageTag = EmailTrack::getHtmlImageTag($urlPixelPageview);


// INSTANTIATE EVENT TACKER
// Email subject, traffic source (utm), campaign (utm)
// For the Spanish office traffic source can be newsletter-socios or newsletter-leads
$myEventTracker = new EmailTrack('Add email subject here', 'newsletter-socios', 'Campaign'); 

// Get a URL with the pageview type
$urlPixelEvent = $myEventTracker->getEventUrl();

// Get a visible html tag with the URL
$imageTagOther = EmailTrack::getHtmlImageTag($urlPixelEvent);

echo("<html>\n\n<head><meta charset='utf-8' /></head>\n\n<body>\n\n");

// DISPLAY PAGEVIEW TRACKER
echo("<pre>\n\n");
echo("URL of the pageview pixel: \n");
print_r($urlPixelPageview);
echo ("\n\n");
echo("Html tag with the pageview pixel: \n");
print_r($imageTag);
echo ("\n\n");
echo("</pre>");

// DISPLAY EVENT TRACKER
echo("<pre>\n\n");
echo("URL of the event pixel: \n");
print_r($urlPixelEvent);
echo ("\n\n");
echo("Html tag with the event pixel: \n");
print_r($imageTagOther);
echo ("\n\n");
echo("</pre>");

echo("\n\n</body>\n</html>");

?>