Phpne august-2012-symfony-components-friends

Symfony Components & Friends
Michael Peacock, PHPNE August 2012

About Me
@michaelpeacock
Head Developer @ Ground Six
Leading the development team and managing the
development process
We are a tech investment company: you bring ideas, we
partner and build the product
Author
Occasional Speaker

Symfony Components
Routing YAML
Event dispatcher Finder
Form Dependency Injection
Process HttpFoundation
Security HttpKernel
Console Locale

Friends

Pimple: dependency injection container
Twig: templating engine
Silex

Why?

Solve common web application problems
Incredibly well documented
Standalone: use them how you want
[Components] Ideal for:
Refactoring

Installing
Create a composer.json ﬁle in the root of your project
{
"require": {

"company/project": "version",
}
}

Download Composer

curl -s https://getcomposer.org/installer | php

Run Composer

php composer.phar install

{

Routing
"require": {
"symfony/routing": "dev-master"
}
}

Looks at the users request and converts it into a
Controller::method paid
Request Context: POST|GET|PUT|DELETE
Looks within a list of pre-deﬁned routes
Returns a class name and a method

Deﬁning Routes

YAML
PHP Code (A collection of Routes)
Annotations

comment_story_add:
pattern: /news/{category}/{date}/{article}
defaults: { class: 'CommentsController::addComment' }
requirements:
date: "[0-9]{2}-[0-9]{2}-[0-9]{4}"
_method: POST

// look in our routes folder
$locator = new SymfonyComponentConfigFileLocator(array(__DIR__ . '/../../'));
$loader = new SymfonyComponentRoutingLoaderYamlFileLoader($locator);
// the URL the user requested / is visiting
$request = (isset($_SERVER['REQUEST_URI'])) ? $_SERVER['REQUEST_URI'] : '';
// combine it with the request method to create a request context
$requestContext = new SymfonyComponentRoutingRequestContext($request,
$_SERVER['REQUEST_METHOD']);
// Create a router
$router = new SymfonyComponentRoutingRouter($locator, 'routes.yml',
array('cache_dir' => null), $requestContext);

try {
$requestURL = (isset($_SERVER['REQUEST_URI'])) ? $_SERVER['REQUEST_URI'] : '';
$requestURL = (strlen($requestURL) > 1) ? rtrim($requestURL, '/') :
$requestURL;
$route = $this->router->match($requestURL);
// explode the resulting route
$usersRoute = explode('::', $route['class']);
$controller = new $usersRoute[0]();
$variables = $route;
unset($variables['name']);
unset($variables['class']);
$action = $controller->$usersRoute[1]($container, $variables);
} catch (SymfonyComponentRoutingExceptionResourceNotFoundException $e) {
header('HTTP/1.0 404 Not Found');
die('Page not found.');
}

Event {
"require": {
"symfony/event-dispatcher": "dev-master"

Dispatcher }
}

At key points in your application you create an event
Pass this event to the dispatcher
Observers listen for specific events
Observers can be ordered - some events are observed by
multiple observers
Example: Displaying a “flash notification”
Set some sessions containing the notification
Redirect the user

Event: Notify
<?php
namespace ProjectFrameworkEvents;

class Notify extends RequestRedirection implements NotifiableMessageInterface
{
protected $notification;
protected $class = 'notice';

public function __construct($url = null, $notification = null, $class = 'notice')
{
parent::__construct($url);
$this->class = $class;
$this->notification = $notification;
}

public function getNotification()
{
return $this->notification;
}

public function getClass()
{
return $this->class;
}

}

<?php

use SymfonyComponentEventDispatcherEvent;

class RequestRedirection extends Event
{
protected $url;

public function __construct($url = null)
{
$this->url = $url;
}

public function getURL()
{
return $this->url;
}
}

<?php

interface NotifiableMessageInterface
{
public function getNotification();
public function getClass();
}

Listener: Set Notiﬁcation
Session
<?php
namespace ProjectFrameworkListeners;

use ProjectFrameworkEvents;

class SetPersistantNotification
{
public function setNotification( EventsNotifiableMessageInterface $event )
{
$_SESSION['system_notification'] = $event->getNotification();
$_SESSION['system_notification_class'] = $event->getClass();
}

}

Listener: Redirect
<?php
namespace ProjectFrameworkListeners;
use ProjectFrameworkEvents;
class Redirect
{
public function redirectUser( EventsRequestRedirection $event )
{
header("Location: " . $event->getURL() );
exit();
}

}

Dispatcher
Create an event dispatcher

Create instance of listener

Add the listener

Event name

Callable: e.g. Object > Method array combo, Closure (event is passed)

Priority: for multiple listeners listening for the same event

$dispatcher = new EventDispatcher();

// Notification (Success, Warning, Error)
$setPersistantNotification = new ListenersSetPersistantNotification();
$dispatcher->addListener('notify', array($setPersistantNotification, 'setNotification'), 10);

// Redirect
$redirectUser = new ListenersRedirect();
$dispatcher->addListener('notifiy', array($redirectUser, 'redirectUser'), 0);

Raise and Dispatch Event

$url = $baseUrl . 'account';
$message = 'Your password was changed successfuly.';
$event = new EventsRedirectableNotification($url, $message, 'success');
$dispatcher->dispatch('notify', $event);

{

Forms
"require": {
"symfony/form": "dev-master"
}
}

A little ﬁddly to get running in a stand-alone mode
READ: I didn’t have time to ﬁgure it out for this talk :-(
Supports:
Creating forms programmatically
Processing form submissions
Uploading Files
Validating submissions with the Validator

Creating a form: with Silex
$data = array();
$data['a_hidden_field'] = 'the value';
$form = $app['form.factory']->createBuilder('form', $data)
->add('image', 'file')
->add('name')
->add('a_hidden_field', 'hidden')
->getform();
return $app['twig']->render('form.twig', array('form' => $form->createView()));

<form action="/" method="post" {{ form_enctype(form) }}>
{{ form_widget(form) }}

<input type="submit" name="submit" />
</form>

Process form submission

if( 'POST' == $request->getMethod()) {
$form->bindRequest($request);
if($form->isValid()) {
$data = $form->getData();
}
}

File upload

$uploadedFile = $form['image']->getData();

$path = $uploadedFile->getPath();
$originalName = $uploadedFile->getOriginalName();
$mimeType = $uploadedFile->getMimeType();

$uploadedFile->move( '/var/www/uploads/upload.png');

{

Validator
"require": {
"symfony/validator": "dev-master"
}
}

Takes a series of constraints
Checks an input against these constraints
Returns a collection of violations

Validation Constraints
Constraints deﬁne the rule that an input must satisfy
Examples:
Min/Max Length
Email
Regex
Date
Min / Max / Null / NotNull / Empty / Not Empty

Documentation Example
<?php
use SymfonyComponentValidatorValidation;
use SymfonyComponentValidatorConstraints as Assert;

$validator = Validation::createValidator();

$constraint = new AssertCollection(array(
'name' => new AssertCollection(array(
'first_name' => new AssertMinLength(101),
'last_name' => new AssertMinLength(1),
)),
'email' => new AssertEmail(),
'simple' => new AssertMinLength(102),
'gender' => new AssertChoice(array(3, 4)),
'file' => new AssertFile(),
'password' => new AssertMinLength(60),
));

$violations = $validator->validateValue($input, $constraint);

{

Security
"require": {
"symfony/security": "dev-master"
}
}

Provides a framework for:
Authentication
Authorisation
Firewall: who can access which areas e.g. “edit”
Access Control: what data the user can
manipulate e.g. edit home page

HTTP {
"require": {
"symfony/http-foundation": "dev-master"

Foundation
}
}

Abstracts core HTTP functions
Request: Super Globals ($_POST, $_GET, etc)
Response: Status Codes, Cache, Cookies, Sessions

HTTPFoundation: Request
Object-Oriented wrapper for SuperGloabls
use SymfonyComponentHttpFoundationRequest;
$request = Request::createFromGlobals();

Property Purpose

request store $_POST

query store $_GET

cookies store $_COOKIE

attributes Application speciﬁc

ﬁles $_FILE

server $_SERVER

headers subset of $_SERVER

ParameterBag
Request properties are all ParameterBag or sub-classes
Provides special methods to manage contents, including:
all
keys
add
get
set
has
remove

$value = $request->query->get(‘my_get_parameter’);

Response
use SymfonyComponentHttpFoundationResponse;

$response = new Response();
$response->setContent('Hello PHPNE');
$response->setStatusCode(200);
$response->headers->set('Content-Type', 'text/plain');

// alternatively...
$response = new Response('Hello PHPNE', 200, array('content-type', 'text/plain'));

$response->prepare();

// send the response to the user
$response->send();

Pimple
{
"require": {
"pimple/pimple": "dev-master"
}
}

Dependency Injection Container
Use it to store and pass objects, and other things
your code depends on
What is dependency injection?
public function __construct()
{
Not injected $this->database = new mysqli();
}

public function __construct($database)
{
Injected $this->database = $database;
}

Pimple: Lazy Loading
We can use anonymous functions to prevent
(dependent) objects being instantiated until they are
needed
$container['database'] = $container->share(function($container) {
try {
$db = new
PDO("mysql:host={$container['database_host']};port={$container['database_port']};dbname={$container['d
atabase_name']}", $container['database_user'], $container['database_pass'], array(PDO::ATTR_PERSISTENT
=> true, PDO::MYSQL_ATTR_INIT_COMMAND => "SET NAMES 'utf8'",PDO::MYSQL_ATTR_USE_BUFFERED_QUERY =>
true));

$db->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);

return $db;
}
catch (PDOException $e) {
echo $e->getMessage();
exit();
}
});

Parameters

$container['my_parameter'] = 'Some Value';

Objects

$container['my_object'] = function($container){
//will return this each and every time $container['my_object'] is accessed
return new MyObject();
};

Sharing Objects
$container['my_object'] = $container->share(function($container){
// will return a new instance first time accessed
// same object returned every other time
return new MyObject();
});

Protecting Parameters

$container['my_object'] = $container->protect(function($container){
// lets you return the result of an anonymous function as a parameter
return some_function();
});

A warning: You can’t modify a parameter

Twig
{
"require": {
"twig/twig": "dev-master"
}
}

Lightweight template engine
Really easy to extend and use

// create a twig filesystem loader so it can access templates
$loader = new Twig_Loader_Filesystem('templates');
// create a new twig environment and pass it the loader
$twig = Twig_Environment($loader);
// load the template
$twig->loadTemplate('index.twig');
// render it
$twig->render(array('title' => 'variable'));

Twig Template Syntax

{{ some_variable }}

{# some comment #}

{% set list_of_items = variable.getItems() %}

{% for item in list_of_items %}
<li>{{loop.index}}: {{item.name}}</li>
{% else %}
<li>Empty :-(</li>
{% endfor %}

Silex
{
"require": {
"silex/silex": "dev-master"
}
}

A “micro-framework” based off some of these
components and pimple
Designed for single-page PHP apps

Silex: A note on closures

Anonymous function: created without a name
Can accept parameters
Can use variables from compile time scope if deﬁned

$objectToInject = new stdClass();
$test = function($parameter) use ($objectToInject){
// here we can use $parameter and $objectToInject
};

Setup

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

use SymfonyComponentHttpFoundationRequest;
use SymfonyComponentHttpFoundationResponse;

use SymfonyComponentProcessProcess;

$app = new SilexApplication();
// Enable debugging.
$app['debug'] = true;

Silex: Before running

$app->before(function () use ($app)
{
$app->register(new SilexProviderTranslationServiceProvider(), array(
'locale_fallback' => 'en',
));
$app->register(new SilexProviderFormServiceProvider());
$app->register(new SilexProviderTwigServiceProvider(), array(
'twig.path' => __DIR__.'/views',
));
$app['conn'] = new mysqli('localhost', 'root', '', 'app');
});

Silex: Routes
$app->get('image.{format}', function( $format ) use ($app)
{
$form = $app['form.factory']->createBuilder('form', array())
->add('image', 'file')
->getform();
return $app['twig']->render("upload.{$format}.twig",
array('title' => 'Upload image', 'form' => $form->createView()));
})->assert('format', 'json|html' );

$app->post('/image.{format}', function( $format, Request $request) use ($app)
{
return $app['twig']->render("image.{$format}.twig", array));
})->assert( 'format', 'json|html');

Silex: Run

$app->run();

Silex & Components

Silex has a number of “providers” which allow certain
components to be plugged in
Silex knows nothing about the component
The component knows nothing about Silex
The provider bridges the gap

Silex Providers:
Doctrine: ORM
URL Generator
Monolog: Sessions
Validator
SwiftMailer
HTTP Cache
Session
Form
Twig
Any that you create
Translation

Conclusion

Lots of components
Solve lots of problems
Easy to use
Why reinvent the wheel? Use a Symfony Component or
one of their friends

Cheers!

Thanks for listening!

mkpeacock@gmail.com
@michaelpeacock

Phpne august-2012-symfony-components-friends

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