@Crell

• Senior Architect, Palantir.net
• Drupal Association Advisor
• Web Services & Context Initiative Owner
• Co-Author,
  Drupal 7 Module Development,
  Packt Publishing
• Architectural Pedant
• Nerf Gunslinger

2% of the Web runs Drupal

Over 1000 Drupal 7 Contributors

Over 20,000 new Drupal 7 sites every month

Conclusion...

Time to kick some ass
in Drupal 8

Drupal is an 11 year old, PHP 4-based extensible Slashdot clone originally written by a Belgian college kid.

Web Services and Context Core Initiative (WSCCI)

The mission...

Drupal needs to evolve, and quickly, from a first-class web CMS into a first-class REST server that includes a first-class web CMS.

Page layout in Drupal 7

Page layout in Drupal 8 (planned)

Why Symfony?

• Just wanted a request/response library
• Symfony2 vs. Zend: Symfony2

  

• Continue implementing
• Oh, wait, you did this already...

  

Drupal 8

(That's the plan, anyway)

The kernel

• We're all in
• HttpFoundation, HttpKernel, Routing, EventDispatcher
• Steer as close to existing components as possible
• Borrow some of the full-stack extensions
  • Extended HttpKernel (forward(), render(), etc.)
  • Auto-loading of controller arguments

Drupal 7 - index.php

/**
 * @file
 * The PHP page that serves all requests on a Drupal installation.
 */

/**
 * Root directory of Drupal installation.
 */
define('DRUPAL_ROOT', getcwd());

require_once DRUPAL_ROOT . '/includes/bootstrap.inc';
drupal_bootstrap(DRUPAL_BOOTSTRAP_FULL);
menu_execute_active_handler();
    

Drupal 8 - index.php

use Drupal\Core\DrupalKernel;
use Symfony\Component\HttpFoundation\Request;

define('DRUPAL_ROOT', getcwd());

// Bootstrap all of Drupal's legacy subsystems.
// @see Drupal\Core\EventSubscriber\PathSubscriber;
// @see Drupal\Core\EventSubscriber\LegacyRequestSubscriber;
require_once DRUPAL_ROOT . '/core/includes/bootstrap.inc';
drupal_bootstrap(DRUPAL_BOOTSTRAP_CODE);

// @todo Figure out how best to handle the Kernel constructor parameters.
$kernel = new DrupalKernel('prod', FALSE);

$request = Request::createFromGlobals();
$response = $kernel->handle($request)->prepare($request)->send();

$kernel->terminate($request, $response);
    

Routing

• A typical Drupal site has ~1000 routes. (That's what happens when you have a powerful UI.)
• New NestedMatcher implementation nearly complete
  • Database-backed, fit-basd algorithm
  • Multi-stage matcher, filter-based
  • Configurable via DIC
  • Will support mimetype-based matching
  • Tentative work on a new stand-alone negotiation library
  • (Likely future extension only; needs help.)
• Will be pushed upstream to Symfony CMF Routing.

Dependency Injection

• Drupal has lots of global dependencies (Procedural code is like that...)
• Start by centralizing the globals...
• "Dependency Injection Container:
  The scariest name for a giant array of objects we could come up with."
• Once they're in the container, easier to refactor

Transitional state

    function drupal_container(ContainerBuilder $reset = NULL) {
      static $container = NULL;
      if (isset($reset)) {
        $container = $reset;
      }
      elseif (!isset($container)) {
        $container = new ContainerBuilder();
      }
      return $container;
    }
    

      $langcode = drupal_container()->get('language_interface')->langcode;
    

EventDispatcher

Hooks

Hooks

Benefits

• Like EventDispatcher, but uses function_exists() for registration
• Used for procedural AOP
• Faster than EventDispatcher
• No need to compile

Limitations

• No class autoloading
• Inherently global dispatcher means hard to unit test
• Only one of each hook per module

Hooks

    function mymodule_node_access($node, $op, $account) {
      if ($op == 'edit'
          && $node->uid == $account->uid
          && $node->created > (REQUEST_TIME - 3600)) {
        return NODE_ACCESS_ALLOW;
      }
      return NODE_ACCESS_IGNORE;
    }
    

        $return = module_invoke_all('node_access', $node, 'update', $account);
      

Hooks in Drupal 8

Prediction (warning, I know better than to gamble):

• Drupal 8 will have both EventDispatcher and Hooks
• EventDispatcher closer to the core, Hooks further out
• Refactor hook engine to not be completely global, for testing
• Drupal 9: Just EventDispatcher? We'll see...

Twig

Templating in Drupal 7

• PHP-as-template-language
• Powerful preprocessing/filtering system.
• Array-based rendering: Defer rendering until the last possible moment

Templating in Drupal 7

Benefits

• Extremely flexible
• No need to compile templates (easier development)
• On-ramp for front-end developers to become PHP developers
• "All template languages eventually evolve to become Turing Complete"

Drawbacks

• Extremely opaque
• That flexibility leads to unpredictability
• Front-end need to become PHP developers

DrupalCon Denver - March 2012

Twig in Drupal 8

Maybe!

Benefits

• More secure
• More front-end developer friendly
• Twig.js (Thank you, Johannes!)
• Not Drupal-proprietary

Drawbacks

• Extremely different model makes transition difficult
• Need to figure out how to secure the compiled templates

We could use a hand!

Replacing NIH with PIE

• Proudly Invented Elsewhere
• YAML Component
• Doctrine Common annotations
• Composer (partially)

Considering...

• Assetic
• Guzzle
• Imagine

Clean up all the things!

• PSR-0
• Gettext
• PhpStorage
• Archiver
• Graph
• Plugin
• Reflection
• And more...

Let's work together

Collaboration

• Symfony2: MIT License
• Drupal: GPL License
• Code only flows one way. :-(
• Work can begin anywhere :-)

Coordination

• Security releases

We're coming upstream

• Symfony2 "flash messages": Too simple for us
• drupal_set_message()
• Make less code in the world!
• Drupalers designed needs for improved API
• Drak (of Zikula CMS) implemented it
• It's now in Symfony 2.1.
• Drupal issue

File Streaming

• Readfile()? fpassthru()? X-Sendfile? One response class.
• Fabien says it should be in HttpFoundation. We agree.
• Drupal issue
• Symfony pull request
• Make less code in the world!

Odds and ends

• Response::prepare() chaining
• Improve FlattenException
• UTF-8 encoding weirdness in JSON
• Allow Router matching on a full Request (still open)
• Make RouteCollection Countable
• Improve Route serialization
• Add lockExists to Store interface
• Expect more...

Why use Drupal, not pure Symfony?

What is Drupal?

Drupal is a platform that allows you to assemble your own CMS (or other application).

Why Drupal and Symfony?

Entities/Fields

Click together your own data structure

Views

Click together your own lists and queries

Drupal

Click together your own site

Distributions: Drupal applications in-a-box

http://www.drupal.org/project/distributions

But wait, there's more!

• Configuration management: Finally, reasonable deployment
• Mobile-friendly administration: Post from your phone
• Improved multi-lingual support
• HTML5 Everywhere
• Responsive Mobile-First themes
• Revamped Entity system
• Block-driven, ESI-friendly layout
• Over 1500 issues closed since Drupal 7 launched and counting...

Do you want Drupal 8?

git clone --recursive --branch 8.x
http://git.drupal.org/project/drupal.git

Do you want help Drupal 8?

#drupal-contribute
Feature freeze - 1st Dec 2012
Code freeze - 1st April 2013
Release ≈ August 2013