Symfony2 components to the rescue of your PHP projects

Symfony2 components to
the rescue of your PHP projects
Xavier Lacot – June 2012

Hello

My name is Xavier Lacot
■ Web and Mobile at http://jolicode.com
■ Formerly PHP technical leader at Clever Age
■ Open Source convinced and contributor
■ In PHP, mainly Symfony
■ In javascript, etc.
■ Président of AFUP – the French PHP Users Association
(afup.org)
■ Forum PHP
■ PHP Tour
■ http://twitter.com/xavierlacot
Symfony2 components to the rescue of your PHP projects 2
JoliCode | Xavier Lacot | Symfony Live 2012

Summary

1. PHP in 2012, a living ecosystem
2. 2005's PHP is now just pain
3. Migration strategies
■ The slow path
■ Switch progressively
4. Symfony components for your pleasure
■ Your prefered migration toolkit
■ Case Study


Before we start

How many of you use a framework on a regular basis?

How many of you must deal with no-framework
applications?


PHP in 2012, a living ecosystem

A few things about PHP

■ A pragmatic language built for the Web
■ PHP5 since 2005
■ One of the most used languages on the Web

PHP – solves problems since 1995


The language improves

■ PHP 5.3 introduced new concepts :
■ Usage of namespaces
namespace JoliCodeConferences;
use GeneralTalkSession;

class SymfonyLive extends Session
{
public function runPresentation()
{
// do something nice...
}
}

■ Lambda and closures
■ Phar archives
■ “goto” WTF ???

Namespaces manipulation

■ Pro
■ No more collisions
■ Less ambiguity
■ Ahah, short class names. No more long classnames
■ Cons
■ Don't forget the use statement

use OneFullClassname as Something;

$object = new Something;


And it still evolves
■ PHP 5.4
■ Some deprecated features removed
■ Performance improvements
■ Instance Method Calls
$post = (new Post)->setTitle('Hello poneys')->save();

■ Closures inside objects
■ Traits, aka. assisted copy/paste
■ Arrays manipulation
function fruits() {
return ['apple', 'banana', 'orange'];
}

echo fruits()[0]; // Outputs: apple


The ecosystem improves

■ Last years = bunch of new things
■ New (versions of) frameworks
■ New tools
■ Dependancies resolution
■ Code analysis
■ Continuous integration
■ Structuration of the projects
■ Standards
■ Discussions
■ More and more conferences


New frameworks


ClassLoader and PSR-0

■ PSR-0 :
■ A standardization agreement
■ Scope: classes naming and organization

class: SymfonyComponentHttpFoundationRequest
path: vendor/src/Symfony/Component/HttpFoundation/Request.php

class: Twig_Extension_Core
path: vendor/twig/lib/Twig/Extension/Core.php

■ Idea : match the path of the file containg a class to
this full class name

ClassLoader and PSR-0

Namespaced classes style
autoloading path prefix

class: SymfonyComponentHttpFoundationRequest
path: vendor/src/Symfony/Component/HttpFoundation/Request.php

class: Twig_Extension_Core
path: vendor/twig/lib/Twig/Extension/Core.php

PEAR naming style


Composer

■ A packages management tool
■ Launched in 2012
■ Composer : a tool for managing
dependancies
■ Packagist.org : a repository of
packages

■ See the talk of Jordi Boggiano
and Nils Adermann


Dependancies resolution using Composer
composer.json
{
"name": "joli/demo-project",
"description": "A simple demo project",
"require": {
"php": ">=5.3.3",
"symfony/symfony": "2.1.*",
"seld/jsonlint": "1.0.0"
}
}

$ php composer.phar install
Installing dependencies from lock file
- Updating twig/twig (dev-master)

■ And more:
■ Post install commands
■ Configuration variables
■ etc.

Packagist

■ The packages repository behind packagist
■ A great resource for finding high quality contributions
■ Definitively forget about PEAR or distro packages

■ Fear that packagist might break? Build your own
repository with satis - https://github.com/composer/satis

PHP gets is a professional language

■ PHP is not anymore an amateur language
■ Continuous integration (hi Jenkins, Sismo and Travis)
■ Unit tests (hi PHPUnit, SimpleTest, Atoum)
■ Code quality analysis and metrics
■ Code improvement tools (Hi PHP-CS-Fixer)
■ etc.
■ PHP developers have grew up since 2002
■ The language is more mature
■ The community too


Cheers GitHub


GitHub

■ Social coding
■ Gathers many Open Source contributions
■ Watch, fork, comment, request pulls
■ Fun and nice
■ 2,500,000 projects,
~ 150,000 PHP projects
■ A great market for the developer!

PHP switched from SVN to Git


Summary

■ The slow path
■ Case study


Oh yes we did it...
somewhere in 2002...
<html>
<body>
<?php
include("includes/menu.inc.php");
$file = (isset($_GET['pages'])) ? "pages/".$_GET['page'].".php" : "pages/404.php";

if ( !file_exists($file) )
{
@include("pages/404.php");
}
else
{
$allowed = realpath('./pages');

if ( !@ereg($allowed."*", realpath($file)) )
{
}
else
{
@include($file);
}
}
?>
</body>
</html>


Oh yes we did it...
<html>
<body>
<?php
■ HTML and PHP mix

{
}
else
{

{
}
else
{
@include($file);
}
}
?>
</body>
</html>


Oh yes we did it...
<html>
<body>
<?php

{
■ Direct access to
}
@include("pages/404.php"); superglobals
else
{

{
}
else
{
@include($file);
}
}
?>
</body>
</html>


Oh yes we did it...
<html>
<body>
<?php

{
■ Direct access to
}
else
{ ■ Use of the @ operator

{
}
else
{
@include($file);
}
}
?>
</body>
</html>


Oh yes we did it...
<html>
<body>
<?php

if ( !file_exists($file) ) ■ Direct access to
{
}
else
{ ■ Use of the @ operator

■ Urls tied to code
{ structure
}
else
{
@include($file);
}
}
?>
</body>
</html>


Oh yes we did it...
<html>
<body>
<?php

if ( !file_exists($file) ) ■ Direct access to
{
}
else
{
■ Use of the @ operator
■ Urls tied to code
{ structure
}
else
■ Duplicate code
{
@include($file);
}
}
?>
</body>
</html>


Not bad at all

■ That was 10 years ago!
■ No PHP5 at that time
■ That was still flexible
■ Just missed some concepts


The shit of today was great yesterday

So how did we improve things?


2004 → 2007

■ First professional PHP frameworks
■ Zend Framework
■ Code Igniter
■ Seagull PHP
■ Cake PHP
■ symfony 1
■ Jelix
■ Pluf
■ Yii
■ etc.


symfony 1

■ End 2005 : first public version (release 0.4)
■ Developers say “hurra”

ORM Functionnal and Unit tests
Ajax Internationalisation
Plugins Community
Console Helpers
Conventions Routing
Debug toolbar Cache
Documentation MVC

Still not sufficient

■ Several limits:
■ Very monolithic
■ Not very flexible
■ Almost no components - use it all or don't use it
■ Some things were a pain to achieve
■ Extensive use of Singleton
■ Hard (impossible) to write complete test suites
■ Developers only
■ Performances... !
■ Lots of bad contribs
■ Low average community level

Summary

■ The slow path
■ Case study


Pre-conditions

■ You work since more than 5 years on your project
■ A bunch of functionnalities
■ The app is in production
■ Lots of users and data
■ A competent team
■ But
■ New developments are slow
■ Infrastructure problems
■ Hard to improve things
■ You want to trash it all, and code like in 2012

Pre-conditions

Your reality


Pre-conditions

Your expectations


Strategy #1 – big bang

■ Most natural approach : rewrite everything
■ Pro:
■ A new solid and modern framework
■ Leave away from the old crappy codebase
■ Feel more happy
■ Cons:
■ Stop the company's business
■ Spend 1y+ re-developing everything
■ Have client cry
■ Complex migration scripts
■ Very risky

Strategy #1 – big bang

■ Don't do that
■ Too risky
■ Lot of pressure
■ Might lead to a disaster
■ Your boss won't be happy

■ Prefer a gradual approach


Strategy #2 – Be progressive

■ Being progressive :
■ Re-write step by step
■ Control the way you build things
■ Use Framework parts, not the complete framework
■ Choose which parts to use
■ Gradually raise the level of your team

■ Less risky
■ And your boss will love you


Step #1

Switch to PHP 5.3 or PHP 5.4
NOW.

*

Historical Historical
codebase codebase

PHP x.x PHP 5.3

JoliCode | Xavier Lacot | Symfony Live 2012 thanks w3techs.com

Step #1

■ Debian users :
■ Update your distribution version (eventually)
■ Update your packages (5 seconds)

■ Mac Users :
■ Please trash wamp and go grab http://php-osx.liip.ch/
(kudos Liip)

■ Windows users
Doh!

Step #2

■ Create a solid foundation for your future new
developments
■ Put new things in your project
■ Symfony components are up! Start with:
■ ClassLoader
■ DependencyInjection
■ HTTPFoundation

ClassLoader
Historical Historical
codebase DIC
codebase
HTTPFoundation


Step #2 – install the components

■ Use composer
{
"autoload": {
"psr-0": {}
},
"name": "xavierlacot/blog",
"description": "My old blog on steroids",
"require": {
"php": ">=5.3.3",
"symfony/class-loader": "2.1.*",
"symfony/dependency-injection": "2.1.*",
"symfony/http-foundation": "2.1.*"
}
}

$ php composer.phar install
Installing dependencies from lock file
- Updating symfony/class-loader (dev-master)



■ What did we install while doing this?
■ ClassLoader allows to load classes automagically, when
required, if they follow a naming convention defined by
PSR-0;
■ DependancyInjection provides a set of tools for building
object and classes in a standardized way, and reduce the
BC breaks;
■ HTTPFoundation is the basic toolkit when working with
HTTP requests (all web pages, for example).

■ We'll see all three later un the presentation


■ Composer is great
■ It comes with an autoloader
■ Using the classes is simple :
index.php
<?php
require 'vendor/autoload.php';

■ And we're ready to start using the component classes!


Step #3 – start using the components

■ HTTPFoundation is the easiest component to start
with – the one you can immediately use without
breaking things
index.php
use SymfonyComponentHttpFoundationRequest;
$request = Request::createFromGlobals();

CreateFromGlobals()
analyses the superglobals
and populates the Request
object


Step #3 – use HTTPFoundation

Time to change your historical code...

$pagename = (isset($_GET['page'])) ? $_GET['page'] : "404";
$file = sprintf('pages/%s.php', $pagename);

becomes

$pagename = $request->query->get('page', '404');
$file = sprintf('pages/%s.php', $pagename);


Step #4

■ There's no step #4
■ The rest of the process is very similar
■ Integrate the component
■ Use it
■ Refactor your code
■ Simplify
■ Iterate – don't break everything at once. Use
components gradually


Symfony components for your pleasure

Summary

■ The slow path
■ Case study


So what are the Symfony Components ?

■ Symfony components are :
■ A set of independent libraries
■ You can use them separately
■ High quality code components, tested and documented
■ Symfony components are not :
■ A bootstrap
■ They do not provide end user fonctionnalities
■ They are the bricks of your new platform, but you
will have to glue them together


Symfony components

■ The complete list is available at
http://symfony.com/components
■ Symfony2 is built with the Symfony components
■ You will often use the symfony standard distribution, which
contains all the components plus some bundles
■ Components do not depend on any third party library
■ All kind of stuff:
■ HTTP management ■ Internationalization process
■ Cache ■ Templating
■ Files finder ■ Forms management
■ Routing management ■ etc.

Symfony components

■ Here is the list of what you can get :
■ BrowserKit
■ ClassLoader ■ HttpKernel
■ Config ■ Locale
■ Console ■ Process
■ CssSelector ■ Routing
■ DependencyInjection ■ Security
■ DomCrawler ■ Serializer
■ EventDispatcher ■ Templating
■ Finder ■ Translation
■ Form ■ Validator
■ HttpFoundation ■ Yaml

Your prefered migration toolkit

■ I won't detail all the components
■ Here are (AMHA) the most useful (and straightforward) when
migrating an old application:
■ ClassLoader
■ Console
■ DependencyInjection
■ Finder
■ HttpFoundation
■ Routing
■ Templating
■ Validator

■ If you want to use more, consider using Symfony2 at some point

ClassLoader

■ loads classes automatically if they follow PSR-0;
■ Migration process:
1. have your classes organization follow PSR-0 (renaming
stuff)
ldap.php src/Ldap/Client.php
<?php <?php
namespace Prefix/Ldap/Client;
class prefixedLdapConnector
{ class Client
public function __construct() {
{ public function __construct()
// stuff {
} // stuff
} }
}

2. Configure the ClassLoader

ClassLoader

■ loads classes automatically if they follow PSR-0;
■ Migration process:
1. have your classes organization follow PSR-0 (renaming
stuff)
ldap.php src/Prefix/Ldap/Client.php
<?php <?php
namespace Prefix/Ldap;
class prefixedLdapConnector
{ class Client
public function __construct() {
{ public function __construct()
// stuff {
} // stuff
} }
}

2. Configure the ClassLoader

ClassLoader

■ Composer's autoloader is taking care of vendors
installed by composer
■ We must declare “our” classes:
index.php
use SymfonyComponentClassLoaderUniversalClassLoader;

$loader = new UniversalClassLoader();
$loader->registerNamespace('Prefix', __DIR__.'/src/');
$loader->register();

■ Possible to declare several namespaces at once:
registerNamespaces(array(...))


Console

■ Your best friend for writing:
■ Command line tasks
■ Cron jobs
■ Repetitive asynchron tasks
■ Pros:
■ Input / Output management
■ Colorization
■ Well written
■ Extensible


Console

■ Add the Console component to composer.json
"require": {
"php": ">=5.3.3",
"symfony/class-loader": "2.1.*",
"symfony/console": "2.1.*",
"symfony/dependency-injection": "2.1.*",
"symfony/http-foundation": "2.1.*"
}

■ Update the dependencies :
$ php composer.phar update
Updating dependencies
- Installing symfony/console (dev-master)

Writing lock file
Generating autoload files


Console
■ Write a new command:
src/Prefix/Command/TwitterCommand.php
<?php
namespace PrefixCommand;

class TwitterCommand extends Command
{
protected function configure()
{
Hint: I did
$this
remove some
->setName('joli:twitter')
“use”
->setDescription('Gets updates from twitter')
statements
;
}

protected function execute(InputInterface $input, OutputInterface $output)
{
$puller = $this->getContainer()->get('joli.twitter.puller');
$output->writeln("Contacting Twitter...");
$data = $puller->pull();

// do stuff with $data

$output->writeln(sprintf('Tweets fetched. %s new tweets', count($tweets)));
}
}


Console

■ Then create the executable file itself:
console.php
#!/usr/bin/env php
<?php
require 'autoload.php';

use PrefixCommandTwitterCommand;
use SymfonyComponentConsoleApplication;

$application = new Application();
$application->add(new TwitterCommand);
$application->run();

■ Fix this file's permissions:
$ chmod 755 console.php


Console

■ And finally run the command:
$ ./console joli:twitter
Contacting Twitter...
Tweets successfuly fetched. 0 new tweets

$ ./console
Console Tool

Usage:
[options] command [arguments]

Options:
--help -h Display this help message.
--quiet -q Do not output any message.
--verbose -v Increase verbosity of messages.
--version -V Display this application version.
--ansi Force ANSI output.
--no-ansi Disable ANSI output.
--no-interaction -n Do not ask any interactive question.

Available commands:
help Displays help for a command
list Lists commands
joli
joli:twitter Gets updates from twitter


Dependency Injection

■ “Dependency Injection” is a rather cryptic name
■ No drugs here, promise
■ Here is an “old school” function prototype:

function makeMenu($sqlConnection, $menu, $nbItems = null, $level =
0, $startingWith = null)
*
■ It is bad, because:
■ The prototype will change when you will have new
requirements
■ The order of the parameters is a hard constraint
■ Maybe one day you'll store menu items in a NoSQL database,
and not in a relational one anymore
Copyright
Symfony2 components to the rescue of your PHP projects me a long long long time ago 70

Your existing app

■ Your existing app does a lot of things
■ Sending emails
■ Parsing data
■ Writing logs
■ Storing data in databases



■ The Dependency Injection component provides a
dependency injection container
■ Imagine a large array of resources widely used in the
whole application
■ This “DIC” has some capacities:
■ Resources are instantiated only when required;
■ It is extensible;
■ Each item of this DIC is called a “service”
■ The SQL connection is a service
■ Passing the DIC to a class automatically gives access to a
large collection of services...!


Initialization Execution
Call the
service

Create services DIC
DIC $container->get('mailer')
bootstrap

Instantiate a
non-existing
service


Implement your own services

■ In the migration plan:
■ convert the “service” functionnalities into real Symfony2
services,
■ Create binding to the existing calls
■ use them like before
■ In the future, put all your services in the container.
■ And use them from there


DIC migration
■ Imagine we have a “Mailer” class:
<?php
namespace PrefixMailer;

class Mailer
{
$prefix = '';

public function send($to, $subject, $body)
{
// etc.
}
}

■ A mail is sent in our code with:
function saveUser($name, $email)
{
// stuff here

$mailer = new Mailer;
$mailer->send($user->getEmail(), 'Welcome '.$user->getName(), 'A test');
}


DIC migration
■ Create the service container:
use SymfonyComponentDependencyInjectionContainerBuilder;

$container = new ContainerBuilder();
$container->register('mailer', 'Mailer');

■ Pass it to our users management class
■ Use it:
function saveUser($name, $email)
{
// stuff here

$mailer = $this->container->get('mailer');
$mailer->send($user->getEmail(), 'Welcome '.$user->getName(), 'A test');

}


DIC migration

■ Benefits:
■ The Mailer object is now only created in one place
■ Its configuration is centralized
■ It is easy to override in the user management class


HttpFoundation

■ We have already used a little the HTTP Foundation
component
■ One core concept of Symfony2 is the coverage of
the framework
■ It handles Requests
■ And returns Responses
Request

User HTTP Application

Response


HttpFoundation

■ HttpFoundation provides concepts for Request and Responses
■ Every input from the user, or output to the user should
pass through this component
■ Request:
use SymfonyComponentHttpFoundationRequest;
$request = Request::createFromGlobals();

■ $request→request represents $_POST
■ $request→query represents $_GET
■ $request→cookies represents $_COOKIE
■ etc.


HttpFoundation

■ Response:
■ Represents the stuff returned to the user through HTTP
use SymfonyComponentHttpFoundationResponse;
$response = new Response();

■ It implements HTTP 1.1, the response is customizable:
$response->setContent('This will be the response content');
$response->headers->set('Content-Type', 'text/html');
$response->setStatusCode(200);

// send the Response
$response->prepare($request);
$response->send();


Migration plan for using HttpFoundation

■ HTTPFoundation will help:
■ Making your application more secure
■ Enforce a normalization of the way the output is sent ot
the user
■ Migration plan:
■ Start with systematically using the Request ibject in place
of the superglobals
■ Use Response objects whenever possible
■ ob_* may help you
■ Use a templating system to move view content in
separate files

Routing Component – what we did before...

■ Didn't you find nasty the way we manage urls in
our old app?

{
}
else
{

{
}
else
{
@include($file);
}
}


Routing Component – what we did before...

■ Yes, it is far from perfect:
■ Urls enforce code organization
■ This system may cause security problems
■ What if the “$allowed” check doesn't work?
■ It is not extensible
■ The url ↔ action matching is hardcoded, which means no
possible alternative
■ Bad for SEO
■ http://example.org/index.php?page=news&id=3657
■ The Symfony2 Routing component helps handling urls
in an abstract way

Routing Component

■ Routing is a mechanism which allows to manage the
address map of an application
■ Very useful:
■ Better SEO
■ Better security
■ Help reorganize the application internally
■ Do not expose the technology you use


Routing

■ There are two types of routing
■ “Descending” routing: maps an URI to an action the application
must complete:
■ /blog must display the list of posts
■ /blog/2010/05/12/un-message.html must display the right post
■ /contact must display the contact form

/blog
User
Descending routing

■ “ascending” routing helps generate nice, SEO compliant URLs


Routing component – migration plan

■ The migration plan for using this component will
strongly depend on the way you developed your
application.
■ Usually:
■ Add the component to composer.json, update
■ In the front controller, use the routing to match certain
urls and handle the request in a clean way
■ This way, it won't affect other URLs
■ Once installed, always use the Router when
exposing new URLs


In our example...
■ First, declare the routes Hint: I did
remove some
// declare the routes “use”
$routes = new RouteCollection(); statements
$routes->add(
'blog_show',
new Route(
'/blog/{year}/{month}/{slug}',
array('pagename' => 'display_blog')
)
);

■ Then, match the requests to find the page to load
$context = new RequestContext();
$context->fromRequest($request);
$matcher = new UrlMatcher($routes, $context);

try $route now
{ contains the
$route = $matcher->match($request->getRequestUri()); matched route
// do things parameters
}
catch (ResourceNotFoundException $e)
Symfony2 // handle the rescue of your } projects
{ components to exception PHP 88

Generating URLs with the Routing Component

■ $router::generate() allows to generate a URL with
parameters:
$generator = new UrlGenerator($routes, $context);
$url = $generator->generate('blog_show', array(
'slug' => 'hello-les-poneys',
'year' => '2011',
'month' => '11'
));
$response->setContent('Please go <a href="'.$url.'">here</a>');
$response->send();

■ Of course, add the Routing as a service to the
container!

Questions ?
Contact
Xavier Lacot
xlacot@jolicode.com
06 51 48 59 73
http://jolicode.com
Twitter : @JoliCode


Credits

■ Photos – thanks to the photographers:
■ http://www.flickr.com/photos/artbandito/67829362/
■ http://capsizedatsea.tumblr.com/post/9559345143
■ http://memegenerator.net


Symfony2 components to the rescue of your PHP projects

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