symfony2 components to the rescue of your php projects
DESCRIPTION
Symfony2 components can be of a great help when trying to improve the level of existing PHP projects. This presentation explains how PHP and its ecosystem evolved during the last 10 years, and focuses on the successive use of several Symfony2 components, to show how useful they are for the PHP developer. The presentation gives some migration strategies, and explains component by component the migration plan and the (possible) implications on the historical code.TRANSCRIPT
Xavier Lacot – June 2012
Symfony2 components to the rescue of your PHP projects
2Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 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
3Symfony2 components to the rescue of your PHP projectsJoliCode | 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
4Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
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
6Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
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
7Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
The language improves
■ PHP 5.3 introduced new concepts :
■ Usage of namespaces
■ Lambda and closures
■ Phar archives
■ “goto” WTF ???
namespace JoliCode\Conferences;use General\Talk\Session;
class SymfonyLive extends Session{ public function runPresentation() { // do something nice... }}
8Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
Namespaces manipulation
■ Pro
■ No more collisions
■ Less ambiguity
■ Ahah, short class names. No more long classnames
■ Cons
■ Don't forget the use statement
use One\Full\Classname as Something;
$object = new Something;
9Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
And it still evolves
■ PHP 5.4
■ Some deprecated features removed
■ Performance improvements
■ Instance Method Calls
■ Closures inside objects
■ Traits, aka. assisted copy/paste
■ Arrays manipulation
$post = (new Post)->setTitle('Hello poneys')->save();
function fruits() { return ['apple', 'banana', 'orange'];}
echo fruits()[0]; // Outputs: apple
10Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
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
11Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
New frameworks
12Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
New frameworks
13Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
ClassLoader and PSR-0
■ PSR-0 :
■ A standardization agreement
■ Scope: classes naming and organization
■ Idea : match the path of the file containg a class to this full class name
class: Symfony\Component\HttpFoundation\Requestpath: vendor/src/Symfony/Component/HttpFoundation/Request.php
class: Twig_Extension_Corepath: vendor/twig/lib/Twig/Extension/Core.php
14Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
ClassLoader and PSR-0
class: Symfony\Component\HttpFoundation\Requestpath: vendor/src/Symfony/Component/HttpFoundation/Request.php
class: Twig_Extension_Corepath: vendor/twig/lib/Twig/Extension/Core.php
PEAR naming style
Namespaced classes styleautoloading path prefix
15Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
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
16Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
Dependancies resolution using Composer
■ And more:
■ Post install commands
■ Configuration variables
■ etc.
{ "name": "joli/demo-project", "description": "A simple demo project", "require": { "php": ">=5.3.3", "symfony/symfony": "2.1.*", "seld/jsonlint": "1.0.0" }}
composer.json
$ php composer.phar installInstalling dependencies from lock file - Updating twig/twig (dev-master)
17Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
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
18Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
19Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
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
20Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
21Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
Cheers GitHub
22Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
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
23Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
24Symfony2 components to the rescue of your PHP projectsJoliCode | 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
2005's PHP is now just pain
26Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
Oh yes we did it...
<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($file)) ) { @include("pages/404.php"); } else { @include($file); } } ?> </body></html>
somewhere in 2002...
27Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
Oh yes we did it...
<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($file)) ) { @include("pages/404.php"); } else { @include($file); } } ?> </body></html>
somewhere in 2002...
■ HTML and PHP mix
28Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
Oh yes we did it...
<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($file)) ) { @include("pages/404.php"); } else { @include($file); } } ?> </body></html>
somewhere in 2002...
■ HTML and PHP mix
■ Direct access to superglobals
29Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
Oh yes we did it...
<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($file)) ) { @include("pages/404.php"); } else { @include($file); } } ?> </body></html>
somewhere in 2002...
■ HTML and PHP mix
■ Direct access to superglobals
■ Use of the @ operator
30Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
Oh yes we did it...
<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($file)) ) { @include("pages/404.php"); } else { @include($file); } } ?> </body></html>
somewhere in 2002...
■ HTML and PHP mix
■ Direct access to superglobals
■ Use of the @ operator
■ Urls tied to code structure
31Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
Oh yes we did it...
<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($file)) ) { @include("pages/404.php"); } else { @include($file); } } ?> </body></html>
somewhere in 2002...
■ HTML and PHP mix
■ Direct access to superglobals
■ Use of the @ operator
■ Urls tied to code structure
■ Duplicate code
32Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
33Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
Not bad at all
■ That was 10 years ago!
■ No PHP5 at that time
■ That was still flexible
■ Just missed some concepts
34Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
The shit of today was great yesterday
So how did we improve things?
35Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
2004 → 2007
■ First professional PHP frameworks
■ Zend Framework
■ Code Igniter
■ Seagull PHP
■ Cake PHP
■ symfony 1
■ Jelix
■ Pluf
■ Yii
■ etc.
36Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
symfony 1
■ End 2005 : first public version (release 0.4)
■ Developers say “hurra”
ORM
Ajax
Plugins
Console
Conventions
Debug toolbar
Documentation
Functionnal and Unit tests
Internationalisation
Community
Helpers
Routing
Cache
MVC
37Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
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
38Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
Migration strategies
40Symfony2 components to the rescue of your PHP projectsJoliCode | 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
41Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
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
42Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
Your reality
Pre-conditions
43Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
Your expectations
Pre-conditions
44Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
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
45Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
■ 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 #1 – big bang
46Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
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
47Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
Step #1
Switch to PHP 5.3 or PHP 5.4
NOW.
thanks w3techs.com*
*
Historical codebase
PHP x.x
Historical codebase
PHP 5.3
48Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
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!
49Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
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
Historical codebase
Historical codebase
ClassLoader
DIC
HTTPFoundation
50Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
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 installInstalling dependencies from lock file - Updating symfony/class-loader (dev-master)
51Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
Step #2 – install the components
■ 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
52Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
Step #2 – install the components
■ Composer is great
■ It comes with an autoloader
■ Using the classes is simple :
■ And we're ready to start using the component classes!
<?phprequire 'vendor/autoload.php';
index.php
53Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
Step #3 – start using the components
■ HTTPFoundation is the easiest component to start with – the one you can immediately use without breaking things
use Symfony\Component\HttpFoundation\Request;$request = Request::createFromGlobals();
CreateFromGlobals() analyses the superglobals and populates the Request object
index.php
54Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
Step #3 – use HTTPFoundation
Time to change your historical code...
becomes
$pagename = (isset($_GET['page'])) ? $_GET['page'] : "404"; $file = sprintf('pages/%s.php', $pagename);
$pagename = $request->query->get('page', '404'); $file = sprintf('pages/%s.php', $pagename);
55Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
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
57Symfony2 components to the rescue of your PHP projectsJoliCode | 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
58Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
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
59Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
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
■ Cache
■ Files finder
■ Routing management
■ Internationalization process
■ Templating
■ Forms management
■ etc.
60Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
Symfony components
■ Here is the list of what you can get :
■ BrowserKit
■ ClassLoader
■ Config
■ Console
■ CssSelector
■ DependencyInjection
■ DomCrawler
■ EventDispatcher
■ Finder
■ Form
■ HttpFoundation
■ HttpKernel
■ Locale
■ Process
■ Routing
■ Security
■ Serializer
■ Templating
■ Translation
■ Validator
■ Yaml
61Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
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
62Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
ClassLoader
■ loads classes automatically if they follow PSR-0;
■ Migration process:
1. have your classes organization follow PSR-0 (renaming stuff)
2. Configure the ClassLoader
<?php
class prefixedLdapConnector{ public function __construct() { // stuff }}
ldap.php<?phpnamespace Prefix/Ldap/Client;
class Client{ public function __construct() { // stuff }}
src/Ldap/Client.php
63Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
ClassLoader
■ loads classes automatically if they follow PSR-0;
■ Migration process:
1. have your classes organization follow PSR-0 (renaming stuff)
2. Configure the ClassLoader
<?php
class prefixedLdapConnector{ public function __construct() { // stuff }}
ldap.php<?phpnamespace Prefix/Ldap;
class Client{ public function __construct() { // stuff }}
src/Prefix/Ldap/Client.php
64Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
ClassLoader
■ Composer's autoloader is taking care of vendors installed by composer
■ We must declare “our” classes:
■ Possible to declare several namespaces at once: registerNamespaces(array(...))
use Symfony\Component\ClassLoader\UniversalClassLoader;
$loader = new UniversalClassLoader();$loader->registerNamespace('Prefix', __DIR__.'/src/');$loader->register();
index.php
65Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
Console
■ Your best friend for writing:
■ Command line tasks
■ Cron jobs
■ Repetitive asynchron tasks
■ Pros:
■ Input / Output management
■ Colorization
■ Well written
■ Extensible
66Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
Console
■ Add the Console component to composer.json
■ Update the dependencies :
"require": { "php": ">=5.3.3", "symfony/class-loader": "2.1.*", "symfony/console": "2.1.*", "symfony/dependency-injection": "2.1.*", "symfony/http-foundation": "2.1.*"}
$ php composer.phar updateUpdating dependencies - Installing symfony/console (dev-master)
Writing lock fileGenerating autoload files
67Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
Console■ Write a new command:
<?phpnamespace Prefix\Command;
class TwitterCommand extends Command{ protected function configure() { $this ->setName('joli:twitter') ->setDescription('Gets updates from twitter') ; }
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))); }}
Hint: I did remove some “use” statements
src/Prefix/Command/TwitterCommand.php
68Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
Console
■ Then create the executable file itself:
■ Fix this file's permissions:
#!/usr/bin/env php<?phprequire 'autoload.php';
use Prefix\Command\TwitterCommand;use Symfony\Component\Console\Application;
$application = new Application();$application->add(new TwitterCommand);$application->run();
console.php
$ chmod 755 console.php
69Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
Console
■ And finally run the command:
$ ./console joli:twitterContacting 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 commandsjoli joli:twitter Gets updates from twitter
70Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
Dependency Injection
■ “Dependency Injection” is a rather cryptic name
■ No drugs here, promise
■ Here is an “old school” function prototype:
■ 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
function makeMenu($sqlConnection, $menu, $nbItems = null, $level = 0, $startingWith = null)
Copyright me a long long long time ago*
*
71Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
72Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
Your existing app
■ Your existing app does a lot of things
■ Sending emails
■ Parsing data
■ Writing logs
■ Storing data in databases
73Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
Dependency Injection
■ 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...!
74Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
Dependency Injection
DICDIC
Initialization Execution
bootstrapCreate services $container->get('mailer')
Instantiate a non-existing
service
Call the service
75Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
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
76Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
DIC migration
■ Imagine we have a “Mailer” class:
■ A mail is sent in our code with:
<?phpnamespace Prefix\Mailer;
class Mailer{ $prefix = '';
public function send($to, $subject, $body) { // etc. }}
function saveUser($name, $email){ // stuff here $mailer = new Mailer; $mailer->send($user->getEmail(), 'Welcome '.$user->getName(), 'A test'); }
77Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
DIC migration
■ Create the service container:
■ Pass it to our users management class
■ Use it:
use Symfony\Component\DependencyInjection\ContainerBuilder;
$container = new ContainerBuilder();$container->register('mailer', 'Mailer');
function saveUser($name, $email){ // stuff here $mailer = $this->container->get('mailer'); $mailer->send($user->getEmail(), 'Welcome '.$user->getName(), 'A test');
}
78Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
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
79Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
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
ApplicationUser
Request
Response
HTTP
80Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
HttpFoundation
■ HttpFoundation provides concepts for Request and Responses
■ Every input from the user, or output to the user should pass through this component
■ Request:
■ $request→request represents $_POST
■ $request→query represents $_GET
■ $request→cookies represents $_COOKIE
■ etc.
use Symfony\Component\HttpFoundation\Request;$request = Request::createFromGlobals();
81Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
HttpFoundation
■ Response:
■ Represents the stuff returned to the user through HTTP
■ It implements HTTP 1.1, the response is customizable:
use Symfony\Component\HttpFoundation\Response;$response = new Response();
$response->setContent('This will be the response content');$response->headers->set('Content-Type', 'text/html');$response->setStatusCode(200);
// send the Response$response->prepare($request);$response->send();
82Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
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
83Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
Routing Component – what we did before...
■ Didn't you find nasty the way we manage urls in our old app?
$file = (isset($_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($file)) ) { @include("pages/404.php"); } else { @include($file); } }
84Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
■ Yes, it is far from perfect:
■ Urls enforce code organization
■ This system may cause security problems
■ What if the “$allowed” check doesn't work?
■ It is not extensible
■ The url ↔ action matching is hardcoded, which means no possible alternative
■ Bad for SEO
■ http://example.org/index.php?page=news&id=3657
■ The Symfony2 Routing component helps handling urls in an abstract way
Routing Component – what we did before...
85Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
Routing Component
■ Routing is a mechanism which allows to manage the address map of an application
■ Very useful:
■ Better SEO
■ Better security
■ Help reorganize the application internally
■ Do not expose the technology you use
86Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
Routing
■ There are two types of routing
■ “Descending” routing: maps an URI to an action the application must complete:
■ /blog must display the list of posts
■ /blog/2010/05/12/un-message.html must display the right post
■ /contact must display the contact form
■ “ascending” routing helps generate nice, SEO compliant URLs
/blog
Descending routingUser
87Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
Routing component – migration plan
■ The migration plan for using this component will strongly depend on the way you developed your application.
■ Usually:
■ Add the component to composer.json, update
■ In the front controller, use the routing to match certain urls and handle the request in a clean way
■ This way, it won't affect other URLs
■ Once installed, always use the Router when exposing new URLs
88Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
In our example...
■ First, declare the routes
■ Then, match the requests to find the page to load
// declare the routes$routes = new RouteCollection();$routes->add( 'blog_show', new Route( '/blog/{year}/{month}/{slug}', array('pagename' => 'display_blog') ));
$context = new RequestContext();$context->fromRequest($request);$matcher = new UrlMatcher($routes, $context);
try{ $route = $matcher->match($request->getRequestUri()); // do things}catch (ResourceNotFoundException $e){ // handle exception }
Hint: I did remove some “use” statements
$route now contains the matched route parameters
89Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
Generating URLs with the Routing Component
■ $router::generate() allows to generate a URL with parameters:
■ Of course, add the Routing as a service to the container!
$generator = new UrlGenerator($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();
90Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
Questions ?Contact
Xavier [email protected] 51 48 59 73
http://jolicode.comTwitter : @JoliCode
91Symfony2 components to the rescue of your PHP projectsJoliCode | Xavier Lacot | Symfony Live 2012
Credits
■ Photos – thanks to the photographers:
■ http://www.flickr.com/photos/artbandito/67829362/
■ http://capsizedatsea.tumblr.com/post/9559345143
■ http://memegenerator.net