Gravatar cache for nette

GravatarPresenter.php

<?php

class GravatarPresenter extends \Nette\Application\UI\Presenter
{

	public function actionDefault($email, $size = 80)
	{
		$this->sendResponse(new GravatarResponse($email, $size));
	}
}

GravatarResponse.php

<?php

use Nette\Image;
use Nette\Object;
use Nette\Application\IResponse;
use Nette\Environment;
use Nette\Http\IRequest as HttpRequest;
use Nette\Http\IResponse as HttpResponse;
use Nette\InvalidArgumentException;



/**
 * Gravatar image response
 *
 * @author Mikulas Dite, Martin Sadovy
 */
class GravatarResponse extends Object implements IResponse
{

	/** @var string uri */
	const URI = 'http://www.gravatar.com/avatar/';

	/** @var int */
	const EXPIRATION = 172800; // two days



        /** @var string|Nette\Image */
        private $image;

        /** @var string */
        private $type;



        /**
         * @param string email
         * @param int size 1-512
         * @param string path
         */
        public function __construct($email, $size = 80, $defaultImage = NULL)
        {
		if ((int) $size < 1 || (int) $size > 512) {
			throw new \InvalidArgumentException('Unsupported size `' . $size . '`, Gravatar API expects `1 - 512`.');
		}


		$arguments = array(
			's' => (int) $size, // size
			'd' => '404', // e404 if not found
			'r' => 'g', // inclusive rating
		);

		$hash = md5(strtolower(trim($email)));

		$file = TEMP_DIR . '/cache/gravatar/' . $hash . '_' . $size . '.jpeg';
		if (!file_exists($file) || filemtime($file) < time() - self::EXPIRATION) {

			if (!file_exists(TEMP_DIR . '/cache/gravatar')) {
				mkdir(TEMP_DIR . '/cache/gravatar');
			}

			$query = http_build_query($arguments);
			$img = @file_get_contents(self::URI . $hash . '?' . $query);

			if ($img != NULL) {
				file_put_contents($file, $img);
			} else {
				file_put_contents($defaultImage, $img);
			}
		}

		$this->image = Image::fromFile($file);
                $this->type = Image::JPEG;
        }



        /**
         * Returns the path to a file or Nette\Image instance.
         * @return string|Nette\Image
         */
        final public function getImage()
        {
                return $this->image;
        }



        /**
         * Returns the type of a image.
         * @return string
         */
        final public function getType()
        {
                return $this->type;
        }



        /**
         * Sends response to output.
         * @return void
         */
        public function send (HttpRequest $httpRequest, HttpResponse $httpResponse)
        {
                echo $this->image->send($this->type, 85);
                // ideálně nastavit content type pomocí $httpResponse->setContentType();
                /** @see http://api.nette.org/2.0/Nette.Web.IHttpResponse.html#_setContentType */
        }
}

Usage in template:
<img src="{plink Gravatar:, 'john@doe.com', 32}">

or with using the default size of 80:
<img src="{plink Gravatar:, 'john@doe.com'}">