WkhtmlToPDF abstraction that can run either localy or remotely, or even can be used as a hosted service.

Configuration.php

<?php

/**
 * This file is part of the Kdyby (http://www.kdyby.org)
 *
 * Copyright (c) 2008, 2012 Filip Procházka (filip@prochazka.su)
 *
 * For the full copyright and license information, please view the file license.txt that was distributed with this source code.
 */

namespace Pdf\DI;

use Kdyby;
use Kdyby\Curl\Request;
use Kdyby\Curl\CurlException;
use Nette;
use Nette\Http\Url;
use Nette\Diagnostics\Debugger;
use Pdf\InvalidStateException;



/**
 * @author Filip Procházka <filip@prochazka.su>
 *
 * @property \Nette\Http\Url $codeUrl
 * @property \Nette\Http\Url $pingUrl
 */
class Configuration extends Nette\Object
{

	/**
	 * @var string
	 */
	public $provider;

	/**
	 * @var string
	 */
	public $apiKey;

	/**
	 * @var string
	 */
	public $tempDir;



	/**
	 * @return \Nette\Http\Url
	 */
	public function getCodeUrl()
	{
		return new Url($this->provider . '/code');
	}



	/**
	 * @return \Nette\Http\Url
	 */
	protected function getPingUrl()
	{
		return new Url($this->provider . '/ping');
	}



	/**
	 * @return bool
	 */
	public function testConnection()
	{
		try {
			$request = new Request($this->getPingUrl());
			$request->headers['X-ApiKey'] = $this->apiKey;
			$response = $request->get();

			if ($response->getResponse() !== 'pong') {
				throw new InvalidStateException($response->getResponse(), $response->headers['Status-Code']);
			}

			return TRUE;

		} catch (CurlException $e) {
			Debugger::log($e, 'curl');

			return FALSE;

		} catch (InvalidStateException $e) {
			Debugger::log($e, 'Pdf');

			return FALSE;
		}
	}

}

exceptions.php

<?php

namespace Pdf;

use Kdyby;
use Nette;



/**
 * @author Filip Procházka <filip@prochazka.su>
 */
interface Exception
{

}



/**
 * @author Filip Procházka <filip@prochazka.su>
 */
class IOException extends \RuntimeException implements Exception
{

}



/**
 * @author Filip Procházka <filip@prochazka.su>
 */
class InvalidArgumentException extends \InvalidArgumentException implements Exception
{

}



/**
 * @author Filip Procházka <filip@prochazka.su>
 */
class InvalidStateException extends \RuntimeException implements Exception
{

}

IGenerator.php

<?php

namespace Pdf;

use Kdyby;
use Nette;



/**
 * @author Filip Procházka <filip@prochazka.su>
 */
interface IGenerator
{

	/**
	 * @param string $html
	 * @return Nette\Application\IResponse
	 */
	function render($html);

}

PdfExtension.php

<?php

/**
 * This file is part of the Kdyby (http://www.kdyby.org)
 *
 * Copyright (c) 2008, 2012 Filip Procházka (filip@prochazka.su)
 *
 * For the full copyright and license information, please view the file license.txt that was distributed with this source code.
 */

namespace Pdf\DI;

use Kdyby;
use Nette;
use Nette\Utils\Validators;



/**
 * @author Filip Procházka <filip@prochazka.su>
 */
class PdfExtension extends Nette\Config\CompilerExtension
{

	/**
	 * @var array
	 */
	public $defaults = array(
		'provider' => 'http://pdf.kdyby.org',
		'apiKey' => NULL,
	);



	public function loadConfiguration()
	{
		$builder = $this->getContainerBuilder();
		$config = $this->getConfig($this->defaults);

		$builder->addDefinition($this->prefix('config'))
			->setClass('Pdf\DI\Configuration')
			->addSetup('$tempDir', array($builder->expand('%tempDir%/pdf')))
			->addSetup('$provider', array($config['provider']))
			->addSetup('$apiKey', array($config['apiKey']));

		$generator = $builder->addDefinition($this->prefix('generator'))
			->setClass('Pdf\IGenerator');

		if (!empty($config['apiKey'])) {
			$generator->setFactory('Pdf\RemoteGenerator');

		} else {
			$generator->setFactory('Pdf\WkhtmltopdfGenerator');
		}
	}



	public function beforeCompile()
	{
		$config = $this->getConfig($this->defaults);
		if (!empty($config['apiKey'])) {
			$configuration = new Configuration();
			$configuration->apiKey = $config['apiKey'];
			$configuration->provider = $config['provider'];

			if ($configuration->testConnection() === FALSE) {
				trigger_error("The Pdf generator is badly configured or components are missing. Please check log.", E_USER_WARNING);
			}
		}
	}



	/**
	 * @param \Nette\Config\Configurator $configurator
	 */
	public static function register(Nette\Config\Configurator $configurator)
	{
		$configurator->onCompile[] = function ($config, Nette\Config\Compiler $compiler) {
			$compiler->addExtension('pdfGenerator', new PdfExtension());
		};
	}

}

RemoteGenerator.php

<?php

/**
 * This file is part of the Kdyby (http://www.kdyby.org)
 *
 * Copyright (c) 2008, 2012 Filip Procházka (filip@prochazka.su)
 *
 * For the full copyright and license information, please view the file license.txt that was distributed with this source code.
 */

namespace Pdf;

use Kdyby;
use Nette;
use Kdyby\Curl\CurlSender;
use Kdyby\Curl\Request;
use Nette\Application\Responses\TextResponse;
use Nette\Diagnostics\Debugger;
use Nette\Utils\Json;



/**
 * @author Filip Procházka <filip@prochazka.su>
 */
class RemoteGenerator extends Nette\Object implements IGenerator
{

	/**
	 * @var \Kdyby\QrEncode\DI\Configuration
	 */
	private $config;

	/**
	 * @var \Kdyby\Curl\CurlSender
	 */
	private $curlSender;



	/**
	 * @param \Kdyby\QrEncode\DI\Configuration $config
	 * @param \Kdyby\Curl\CurlSender $curlSender
	 */
	public function __construct(DI\Configuration $config, CurlSender $curlSender = NULL)
	{
		$this->config = $config;
		$this->curlSender = $curlSender ?: new CurlSender();
	}



	/**
	 * @param string $html
	 * @return \Nette\Application\IResponse|\Nette\Application\Responses\TextResponse
	 * @throws InvalidStateException
	 */
	public function render($html)
	{
		$request = new Request($this->config->getCodeUrl());
		$request->headers['X-ApiKey'] = $this->config->apiKey;
		$request->setTimeout(45);
		$request->setSender($this->curlSender);

		try {
			$response = $request->post(array('body' => (string) $html));
			if ($response->headers['Content-Type'] === 'application/pdf') {
				return new TextResponse($response->getResponse());
			}

			$json = Json::decode($response->getResponse(), Json::FORCE_ARRAY);
			throw new InvalidStateException($json['error']);

		} catch (Kdyby\Curl\Exception $e) {
			throw new InvalidStateException($e->getMessage(), $e->getCode(), $e);
		}
	}

}

WkhtmltopdfGenerator.php

<?php

namespace Pdf;

use DOMDocument;
use Kdyby;
use Nette\Utils\Json;
use Nette\Utils\Strings;
use Nette;
use Wkhtmltopdf\Document;



/**
 * @author Filip Procházka <filip@prochazka.su>
 */
class WkhtmltopdfGenerator extends Nette\Object implements IGenerator
{

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



	/**
	 * @param string $tempDir
	 */
	public function __construct(DI\Configuration $config)
	{
		if (!is_dir($config->tempDir)) {
			umask(0);
			mkdir($config->tempDir, 0777);
		}

		$this->tempDir = $config->tempDir;
	}



	/**
	 * @param string $html
	 * @return \Wkhtmltopdf\Document|\Nette\Application\IResponse
	 */
	public function render($html)
	{
		$pdf = new Document($this->tempDir);
		$pdf->addHtml($html = (string) $html);
		$this->loadOptionsFromBody($pdf, $html);

		return $pdf;
	}



	/**
	 * @param \Wkhtmltopdf\Document|\Wkhtmltopdf\PageMeta $pdf
	 * @param string $html
	 * @throws \Nette\MemberAccessException
	 */
	private function loadOptionsFromBody($pdf, $html)
	{
		$dom = new DomDocument('1.0', 'UTF-8');
		$dom->resolveExternals = FALSE;
		$dom->validateOnParse = FALSE;
		$dom->preserveWhiteSpace = FALSE;
		$dom->strictErrorChecking = FALSE;
		$dom->recover = TRUE;

		@$dom->loadHTML($html);

		$propertyName = function ($name) use ($pdf) {
			foreach (array_keys(get_object_vars($pdf)) as $propertyName) {
				if (strcasecmp($name, $propertyName) == 0) {
					return $propertyName;
				}
			}

			throw new Nette\MemberAccessException("Cannot write to an undeclared property " . get_class($pdf) . "::\$$name.");
		};

		foreach ($dom->getElementsByTagName('body') as $body) {
			/** @var \DOMElement $body */
			foreach ($body->attributes as $attrName => $value) {
				/** @var \DOMAttr $value */
				if (stripos($attrName, 'data-pdf-') !== 0) {
					continue;
				}

				$property = $propertyName(substr($attrName, 9));
				if (in_array(substr($value->value, 0, 1), array('[', '{'))) {
					$pdf->$property = Json::decode($value->value);

				} elseif ($value->value == 'false') {
					$pdf->$property = FALSE;

				} elseif ($value->value == 'true') {
					$pdf->$property = TRUE;

				} else {
					$pdf->$property = $value->value;
				}
			}

			break;
		}
	}


}