Desymfony2013.gonzalo123

PHP (83%)JavaScript (10%)Python (1%)VimL (1%)C# (1%)Shell (1%)

@gonzalo123http://gonzalo123.comhttps://github.com/gonzalo123http://www.linkedin.com/in/gonzaloayuso

Hello my name is ...

Gonzalo Ayuso

(according to github)

Desymfony 2013 Madrid @gonzalo123 http://gonzalo123.com

http://gonzalo123.comhttp://katayunos.com

You can find me at ...


Why should we use Dependency Injection?


S Single responsibilityO Open/closed principle

L Liskov substitutionI Interface segregation

D Dependency inversion principle

S.O.L.I.D.


IoC and TDD

Dependency injection is a requirement if you want to write testable code.


class Order{ public function generateOrderForUser($user) { $backend = new BackendOrder('dsn:...'); $orderId = $backend->createOrder();

$pdfGenerator = new PDFGenerator(); $pdf = $pdfGenerator->getPDF($orderId);

$mailer = new Mailer('mailCredentials...'); $mailer->sendPdfToUSer($pdf, $user); }}

$order = new Order();

$order->generateOrderForUser('Gonzalo');

One example. It works but ...







Be decoupled my friend







Magic strings are evil







Can we change anything?




// remember to remove this comment when we deploy //$mailer = new Mailer('mailCredentials...'); //$mailer->sendPdfToUSer($pdf, $user); }}



Can we change anything?Open/Close Principle

Desymfony 2013. Madrid @gonzalo123 http://gonzalo123.com

class Order{ private $backend, $pdf, $mailer; public function __construct(BackendOrder $backend, PDFGenerator $pdf, Mailer $mailer) { $this->backend = $backend; $this->pdf = $pdf; $this->mailer = $mailer; } public function generateOrderForUser($user) { $orderId = $this->backend->createOrder(); $pdf = $this->pdfGenerator->getPDF($orderId); $this->mailer->sendPdfToUSer($pdf, $user); }}$backend = new BackendOrder('dsn:...');$pdfGenerator = new PDFGenerator();$mailer = new Mailer('mailCredentials...');

$order = new Order($backend, $pdfGenerator, $mailer);$order->generateOrderForUser('Gonzalo');

Refactor -> DI




Refactor -> DI

And that's

all folks!


The Hollywood principle

"Don't call us, we'll call you."




Where is the problem now?




What can we do?


Dependency Injection Containers (DIC) to the rescue!


Dependency Injection Containers (DIC) in PHP? Are u crazy?


Yes! DIC in PHP:


<?php

class Container {

protected $s=array();

function __set($k, $c) { $this->s[$k]=$c; }

function __get($k) { return $this->s[$k]($this); }

}

TwitteA Dependency Injection Container in a Tweet


$c = new Container();$c->backend_driver = function () { return 'dsn:...'; };$c->backend = function ($c) { return new BackendOrder($c->backend_driver);};$c->pdfGenerator = function ($c) { return new PDFGenerator();};$c->mailer_credentials = function () { return 'mailCredentials...'; };$c->mailer = function ($c) { return new Mailer($c->mailer_credentials);};$c->order = function ($c) { return new Order($c->backend, $c->pdfGenerator, $c->mailer);};$order = $c->order;$order->generateOrderForUser('Gonzalo');

TwitteA Dependency Injection Container in a Tweet


$c = new Pimple();

$c['backend_driver'] = 'mysql:...';$c['backend'] = function ($c) { return new BackendOrder($c['backend_driver']);};$c['pdfGenerator'] = function ($c) { return new PDFGenerator();};$c['mailer_credentials'] = 'mailCredentials...';$c['mailer'] = function ($c) { return new Mailer($c['mailer_credentials']);};$c['order'] = function ($c) { return new Order($c['backend'], $c['pdfGenerator'], $c['mailer']);};$order = $c['order'];$order->generateOrderForUser('Gonzalo');

PimpleA Simple Dependency Injection Container for PHP 5.3


class MyContainer extends Pimple{ public function __construct() { $this['backend_driver'] = 'dsn:...'; $c['backend'] = function ($this) { return new BackendOrder($this['backend_driver']); }; $c['pdfGenerator'] = function ($c) { return new PDFGenerator(); }; $this['mailer_credentials'] = 'mailCredentials...'; $this['mailer'] = function ($this) { return new Mailer($this['mailer_credentials']); }; $this['order'] = function ($this) { return new Order($this['backend'], $this['pdfGenerator'], $this['mailer']); }; }}$c = new MyContainer();$order = $c['order'];$order->generateOrderForUser('Gonzalo');

PimpleA Simple Dependency Injection Container for PHP 5.3


composer.json

{

"require": {

"symfony/dependency-injection": "v2.3.0",

"symfony/yaml": "v2.3.0",

"symfony/config": "v2.3.0"

}

}

Symfony DIC


services.ymlparameters: backend.driver: dsn:... mailer.credentials: mailCredentials...

services: backend: class: BackendOrder arguments: [%backend.driver%]

pdfGenerator: class: PDFGenerator

mailer: class: Mailer arguments: [%mailer.credentials%]

order: class: Order arguments: [@backend, @pdfGenerator,@mailer]

Symfony DIC


index.phpuse Symfony\Component\DependencyInjection\ContainerBuilder;use Symfony\Component\Config\FileLocator;use Symfony\Component\DependencyInjection\Loader\YamlFileLoader;

$container = new ContainerBuilder();$loader = new YamlFileLoader($container, new FileLocator(__DIR__));$loader->load('services.yml');

$order = $container->get('order');$order->generateOrderForUser('Gonzalo');

Symfony DIC


● Symfony2 (Symfony\DependencyInjection)● Zend Framework2 (Zend\Di)● Silex (Pimple)● Laravel (Illuminate\Container)

Modern frameworks and DIC


Usar contenedores o no usarlos

Use an IoC container wisely, not promiscuously

To use or not to use DIC


Let's code!


services.ymlparameters: twig.cache: /path/to/cache/path twig.auto_reload: true

db.dsn: sqlite::memory db.username: username db.password: password

services: database: class: PDO arguments: [%db.dsn%, %db.username%, %db.password%]

Scaling our services.yml


services.ymlimports: - resource: twig.yml - resource: database.yml

twig.ymlparameters: twig.cache: /path/to/cache/path twig.auto_reload: true

database.ymlparameters: db.dsn: sqlite::memory db.username: username db.password: passwordservices: database: class: PDO arguments: [%db.dsn%, %db.username%, %db.password%, ]

Scaling our services.yml


require_once __DIR__.'/vendor/autoload.php';

$app = new Silex\Application();

$app->get('/hello/{name}', function($name) { return 'Hello '.strtoupper($name);});

$app->run();

Silex example


// services.ymlservices: capitalizer: class: Capitalizer

use Symfony\Component\DependencyInjection\ContainerBuilder;use Symfony\Component\Config\FileLocator;use Symfony\Component\DependencyInjection\Loader\YamlFileLoader;

$container = new ContainerBuilder();$loader = new YamlFileLoader($container, new FileLocator(__DIR__));$loader->load('services.yml');

$app = new Silex\Application();$app['container'] = $container;

$app->get('/hello/{name}', function($name) use($app) { $capitalizer = $app['container']->get('capitalizer'); return 'Hello '. $capitalizer->toUpper($name);});

$app->run();

Silex example with DIC


Almost the end ...

● Be decoupled my friend● S.O.L.I.D.● DI is good ● DIC are tools to help us.● PHP has different DICs● Symfony DIC is very

easy to implement, configurable and easy to extend


Thank you! - ¡Gracias! - ¡Eskerrik asko!

Your turn. Questions?Desymfony 2013 Madrid @gonzalo123 http://gonzalo123.com

http://gonzalo123.comgonzalo123

http://joind.in/talk/view/8843

http://gonzalo123.com

http://gonzalo123.com

https://twitter.com/gonzalo123

https://twitter.com/gonzalo123



Date post:	11-Nov-2014
Category:	Technology
Upload:	gonzalo-ayuso
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Desymfony2013.gonzalo123

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