Simple image view helper for Zend Framework

Here’s a simply view helper for the Zend Framework that can be used to display image tags. It checks to see if the image file exists and if not then it’ll use the data url scheme to output a very simple image that, ironically, says ‘NO IMG’ on it. Please note, though, that I’ve only seen Firefox support this scheme, as wonderful as it is!

< ?php

class Zend_View_Helper_Img
{
    public $view;
    protected static $_baseurl = null;
    protected static $_cache = null;

    /**
     * Constructor
     */
    public function __construct()
    {
        if (null === self::$_baseurl) {
            $url = Zend_Controller_Front::getInstance()->getRequest()->getBaseUrl();
            $root = '/' . trim($url, '/');
            if ('/' == $root) {
                $root = '';
            }
            self::$_baseurl = $root . '/';
        }
    }

    /**
     * Output the <img /> tag
     *
     * @param string $path
     * @param array $params
     * @return string
     */
    public function img($path, $params = array())
    {
        $plist = array();
        $paramstr = null;
        $imagepath = self::$_baseurl . ltrim($path, '/');
        if (!isset(self::$_cache[$path])) {
            self::$_cache[$path] = file_exists(realpath($_SERVER['DOCUMENT_ROOT'] . '/' . $imagepath));
        }
        if (!isset($params['alt'])) {
            $params['alt'] = '';
        }
        foreach ($params as $param => $value) {
            $plist[] = $param . '="' . $this->view->escape($value) . '"';
        }
        $paramstr = ' ' . join(' ', $plist);
        return '<img src="' .
                ((self::$_cache[$path])
                    ? self::$_baseurl . ltrim($path, '/')
                    : 'data:image/gif;base64,R0lGODlhFAAUAIAAAAAAAP///yH5BAAAAAAALAAAAAAUABQAAAI5jI+pywv4DJiMyovTi1srHnTQd1BRSaKh6rHT2cTyHJqnVcPcDWZgJ0oBV7sb5jc6KldHUytHi0oLADs=') .
                '"' . $paramstr . ' />';
    }

    /**
     * Set the view object
     *
     * @param Zend_View_Interface $view
     * @return void
     */
    public function setView(Zend_View_Interface $view)
    {
        $this->view = $view;
    }
}

Usage is really easy:

< ?php echo $this->img('/images/logo.png', array('id' => 'logo', 'title' => 'Cool Company')); ?>