PHP Alexa Rank Fetcher Class

The most well known online website popularity measuring stick appears to be Alexa. Alexa provides a wealth of information on a given website, most notably:

• Popularity rank (the most important one)
• Reach
• In-links
• Speed

Alexa provides this information in many useful formats, including XML. Using the XML provided by Alexa, we can gain access to Alexa information within our pages. I've created a PHP class to make fetching Alexa data free, quick, and easy. The class comes in a PHP4 version and a PHP5 version.

The Code - PHP4 Version

/* the alexa rank class */

class alexa

{

/* initial vars */

var $xml;

var $values;

var $alexa_address;

/* the constructor */

function alexa($alexa_address,$domain)

{

$this->alexa_address = $alexa_address;

$this->xml = $this->get_data($domain);

$this->set();

}

/* gets the xml data from Alexa */

function get_data($domain)

{

$url = $this->alexa_address.'http://'.$domain;

$xml = file_get_contents($url);

return $xml;

}

/* set values in the XML that we want */

function set()

{

$this->values['rank'] = (preg_match('/POPULARITY URL="[a-z0-9\\-\\.\\/]{1,}" TEXT="([0-9]{1,12})"/',$this->xml,$regs) ? number_format($regs[1]) : 0);

$this->values['reach'] = (preg_match('/REACH RANK="([0-9]{1,12})"/',$this->xml,$regs) ? number_format($regs[1]) : 0);

$this->values['linksin'] = (preg_match('/LINKSIN NUM="([0-9]{1,12})"/',$this->xml,$regs) ? number_format($regs[1]) : 0);

}

/* returns the requested value */

function get($value)

{

return (isset($this->values[$value]) ? $this->values[$value] : '"'.$value.'" does not exist.');

}

}

The Code - PHP5 Version

/* the alexa rank class */

class alexa

{

/* initial vars */

var $xml;

var $values;

var $alexa_address;

/* the constructor */

function alexa($alexa_address,$domain)

{

$this->alexa_address = $alexa_address;

$this->xml = $this->get_data($domain);

$this->set();

}

/* gets the xml data from Alexa */

function get_data($domain)

{

$url = $this->alexa_address.'http://'.$domain;

$xml = simplexml_load_file($url) or die('Cannot retrieve feed');

return $xml;

}

/* set values in the XML that we want */

function set()

{

$this->values['rank'] = ($this->xml->SD->POPULARITY['TEXT'] ? number_format($this->xml->SD->POPULARITY['TEXT']) : 0);

$this->values['reach'] = ($this->xml->SD->REACH['RANK'] ? number_format($this->xml->SD->REACH['RANK']) : 0);

$this->values['linksin'] = ($this->xml->SD->LINKSIN['NUM'] ? number_format($this->xml->SD->LINKSIN['NUM']) : 0);

}

/* returns the requested value */

function get($value)

{

return (isset($this->values[$value]) ? $this->values[$value] : '"'.$value.'" does not exist.');

}

}

Using cURL

If you'd rather use the cURL library, you can simply modify the get_data() function:

/* gets the XML data from Alexa */

function get_data($domain)

{

$url = $this->alexa_address.'http://'.$domain;

$ch = curl_init();

$timeout = 5;

curl_setopt($ch,CURLOPT_URL,$url);

curl_setopt($ch,CURLOPT_RETURNTRANSFER,1);

curl_setopt($ch,CURLOPT_CONNECTTIMEOUT,$timeout);

$xml = curl_exec($ch);

curl_close($ch);

return $xml;

}

The Usage

Provide two paramenters: the path to the XML file (minus the domain) and the domain.

/* retrieve & display rank */

$alexa_connector = new alexa('http://alexa.com/xml/dad?url=','digg.com'); // domain only!

echo 'Rank :: '.$alexa_connector->get('rank'); 

echo '';

echo 'Reach :: '.$alexa_connector->get('reach'); 

echo '';

echo 'Links In :: '.$alexa_connector->get('linksin'); 

Do you have any suggestions for this class?