Drupalcon Denver 2012 - Symfony meets Drupal 8 by Fabien Potencier

drupalcondenver2012-fabpotsymfonymeetsdrupal.txt

Collaboration 
- symfony code based on github
- GPL / MIT license compatible

Example of Symfony vs Drupal
- drupal_set_message() vs flash messages
- drupal team evaluated

What is symfony (version 2) ?
- symfony version 1 is totally different
- reusable set of decoupled tools
- solved problems without use other components
- borrow ideas from other languages 
- full stack php framework

Developer tools
- silex microframework
- ppi

Products
- phpbb
- zilex (post nuke)

Components being used
- classloader
- httpkernel
- httpfoundation

How to get symfony
- git
- curl 
- composer

Classloader component
- only load classes on demand
- symfony.com/psr0 - url that contains standard for class loader
-  first require 

http loader
- symfony leverages loader 
- uses specification on http 1.1 rfc2616
- read the http document http://www.ietf.org/rfc/rfc2616.txt
- based on this specification

symfony response header
- nice abstraction to create a response and request
- try to be as much php compliant
- tweak the response

routing
- drupal has too many routes
- creating route in symfony
- define a pattern 
- create a urlmatcher and it returns an an array, id,controller

eventdispatcher 
- probably won't use in drupal 8
- create a dispatcher
- central object for event handling
- dispatcher adds a listener - event name and make it callable
- implements observer design pattern

httpkernel
- most important http code
- httpkernal interface is the only thing in you need to be compatible with all other projects
- when request comes in listeners can do something with request
- listeners can inject arguments
- if listener returns a response - skips intemediary step
- if request even doesn't provide response - create a controller
- becomes another interface
- response can be cached and converted to response
- each method returns php controller
- resolve arguments
- each response provides a terminate
- allows to be interopable

built in listener 
- symfony comes with lots of listeners out of the box
- many exceptions that convert to response

http testing
- kernal allows ability to create tests
- allows ability to create requests in code

caching
- symfony doesn't provide any caching on application layer
- relies on http caching on ietf specification

two different caching models
1. cache-control expires - provide header with cache-control
  - can be browser cache 
2. validation 
  - last-modified
  - if-modified-since
  - etag
  - if-none-match

Expiration over validation
- can use both methods
- proxy implemented

varnish
- symfony allows you to use http varnish http accelerator
- cannot do this if you have proprietary caching mechanism

Edge side includes
-  defined by w3c - http://www.w3.org/TR/esi-lang
- example of edge side include - login form is dynamic and changing
- utilize http expiration and validation 
- add esi include tags ... <esi ...
- esi allows for many different parts page to use expiration and validation (expire in 10 seconds)