root/trunk/Phergie/Plugin/Convert.php

<?php

/**
 * Performs and responds with messages containing the results of conversions
 * between different units.
 */
class Phergie_Plugin_Convert extends Phergie_Plugin_Abstract_Command
{
    /**
     * Returns whether or not the plugin's dependencies are met.
     *
     * @param Phergie_Driver_Abstract $client Client instance
     * @param array $plugins List of short names for plugins that the
     *                       bootstrap file intends to instantiate
     * @see Phergie_Plugin_Abstract_Base::checkDependencies()
     * @return bool TRUE if dependencies are met, FALSE otherwise
     */
    public static function checkDependencies(Phergie_Driver_Abstract $client, array $plugins)
    {
        if (!extension_loaded('Dom')) {
            return 'Dom php extension is required';
        }

        return true;
    }

    /**
     * Performs a unit conversion and returns the result in a message.
     *
     * @param string $convert Conversion to perform
     * @return void
     */
    public function onDoConvert($convert)
    {
        $target = $this->event->getNick();

        $context = stream_context_create(array(
            'http' => array(
                'timeout' => 5,
                'user_agent' => 'Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9b3) Gecko/2008020514 Firefox/3.0b3'
            )
        ));

        $url = 'http://www.google.com/search?q=' . urlencode($convert) . '&btnG=Google+Search&aq=f';
        $contents = @file_get_contents($url, null, $context);
        if (empty($contents)) {
            $this->debug('Empty response');
            return;
        }

        $doc = new DomDocument();
        @$doc->loadHTML($contents);
        $xpath = new DomXPath($doc);
        $result = $xpath->query('//h2/font/b');
        if ($result->length) {
            $children = $result->item(0)->childNodes;
            $text = str_replace(array(chr(195), chr(151)), array('x', ''), $children->item(0)->nodeValue);
            if ($children->length >= 3) {
                $text .= '^' . $children->item(1)->nodeValue . $children->item(2)->nodeValue;
            }
            $this->doPrivmsg($this->event->getSource(), $target . ': ' . $text);
        } else {
            $this->doNotice($target, 'Computation error, nothing was returned');
        }
    }
}