Enhancing Dynamic Twitter Signature Images with PHP

Before we get too involved, let’s take a moment to look at the code that we’ve built so far.

class SignatureImage

{

    private $screen_name;

    private $profile_image;

    private $status_text;

    private $local_avatar;

    public function __construct($name, $bg_image, $adir)

    {

        $this->fetchUserInfo(strtolower($name));

        $this->fetchAvatar($this->profile_image, $adir);

    }

    private function fetchUserInfo($name)

    {

        $url = "http://twitter.com/statuses/user_timeline/{$name}.xml?count=1";

        $xml = $this->curlRequest($url);

        if ($xml === false) {

            // User feed unavailable.

        }

        $statuses = new SimpleXMLElement($xml);

        if (!$statuses || !$statuses->status) {

            // Invalid user channel.

        }

       foreach ($statuses->status as $status) {

            $this->status_text   = (string) $status->text;

            $this->profile_image = (string) $status->user->profile_image_url;

            $this->screen_name   = (string) $status->user->screen_name;

            break;

        }

    }

    private function curlRequest($url)

    {

        if (!extension_loaded('curl')) {

            // PHP extension CURL is not loaded.

        }

        $curl = curl_init($url);

        curl_setopt($curl, CURLOPT_HEADER, false);

        curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);

        $result = curl_exec($curl);

        if (curl_errno($curl) !== 0 || curl_getinfo($curl, CURLINFO_HTTP_CODE) !== 200) {

            $result === false;

        }

        curl_close($curl);

        return $result;

    }

    private function fetchAvatar($url, $adir)

    {

        $fname      = end(explode('/', $url));

        $adir       = preg_match('#^(.*?)/$#i', $url) ? $adir : "{$adir}/";

        $fname      = $adir . $fname;

        if ( !file_exists($fname) ) {

            $img = $this->curlRequest($url);

            $fp = fopen($fname, 'w');

            fwrite($fp, $img);

            fclose($fp);

        }

        $this->local_avatar = $fname;

    }

}

The code we have so far will accept a user name and retrieve the XML status feed using the Twitter API.  Then it parses that information, assigns some class-level variables, and creates a local copy of the user’s Twitter avatar.  Now we need to assemble these pieces into a single “signature” image.  To do that we’ll create a function called renderImage.  So let’s go ahead and complete the class’s constructor with a call to this function.

    public function __construct($name, $bg_image, $adir)

    {

        $this->fetchUserInfo(strtolower($name));

        $this->fetchAvatar($this->profile_image, $adir);

        $this->renderImage();

    }