Dissecting an MVC application

Dissecting an MVC Application Stefan Priebsch, thePHP.cc php|tek 09, Chicago, U.S.A.

Stefan Priebsch Co-Founder and Principal Consultant

MVC

Model View Controller

Model

View

Controller

Separate logic and presentation

Where to put business logic?

Where to put validation?

Lean controllers

MVC Application Components

Front Controller
Router
Controller
View
Domain Model

The controller selects the view

class Controller { public function executeAction() { ... return new View(); } }

class Controller { public function executeAction() { ... return 'ViewName'; } }

Decoupling the view

class MyView extends View { public function render(...) { .... } ... }

interface ViewInterface { public function render(); }

class MyView implements ViewInterface { public function render(...) { ... } }

class MyView extends SomeView implements ViewInterface { public function render(...) { return $this->toHtml(...); } }

class MyView implements ViewInterface { public function render(...) { $view = new SomeView(); return $view->toHtml(...); } }

Request and Response objects

class Controller { public function executeAction() { $user = $_POST['username']; … header('Content-type: ...'); … } ... }

class Request { public function __construct (array $get, array $post, array $cookies, array $server, …) public function getGet($key) public function getPost($key) public function hasCookie($name) public function getCookie($name) public function getServer($key) … }

class Response { protected $httpStatus = 200; protected $contentType = 'text/html'; protected $charset = 'UTF-8'; protected $viewName; ... public function setStatus($status) { $this->httpStatus = $status; } public function getStatus() { return $this->httpStatus; } ... }

class Controller { public function executeAction($request, $response) { $user = $request->getPost('username'); … $response->setContentType(...); … } }

Clearly separate data access from logic

class SomeController { public function executeAction() { … $domainObject = DomainObject::findById($id); ... } }

class DomainObjectManager { public function findById($id) { ... return new DomainObject($id, ...); } public function findAll() { … return array($obj, $obj, $obj, ...); } public function findBySomeCriteria(...) { … return array(...); } ... }

class SomeController { public function executeAction() { … $manager = new DomainObjectManager(); $domainObject = $manager->findById($id); ... } }

class SomeController { protected $manager; public function __construct(Manager $manager) { $this->manager = $manager; } public function executeAction() { … $domainObject = $this->manager->findById($id); ... } }

class SomeController { protected $manager; public function __construct(Manager $manager = null) { if (!is_null($manager)) { $this->manager = $manager; } else { $this->manager = new DomainObjectManager(); } } public function executeAction() { … $domainObject = $this->manager->findById($id); ... } }

class SomeControllerTest { public function testExecuteAction() { $manager = new MockDomainObjectManager() $controller = new SomeController($manager); $controller->execute(); ... } } class MockDomainObjectManager { public function getById($id) { return new DomainObject($id, ...); } }

Testing the authentication controller

class AuthenticationController { public function loginAction() { session_start(); $_SESSION['username'] = 'Stefan'; } public function logoutAction() { session_start(); unset($_SESSION['username']); session_destroy(); } }

require 'PHPUnit/Framework.php'; class AuthContrTest extends PHPUnit_Framework_TestCase { public function testLogin() { $controller = new AuthenticationController(); $controller->loginAction(); $this->assertEquals('Stefan', $_SESSION['username']); } }

class AuthenticationController { public function __construct($session) { $this->session = $session; } public function loginAction() { $this->session->start(); $this->session->register('username', 'Stefan'); } public function logoutAction() { $this->session->start(); $this->session->unregister('username'); $this->session->destroy(); } }

class Session { public function start() { session_start(); } public function register($key, $value) { $_SESSION[$key] = $value; } public function unregister($key) { unset($_SESSION[$key]); } public function destroy() { session_destroy(); } }

require 'PHPUnit/Framework.php'; class AuthContrTest extends PHPUnit_Framework_TestCase { public function testLogin() { $session = new Session(); $controller = new AuthenticationController($session); $controller->loginAction(); $this->assertEquals('Stefan', $_SESSION['username']); } public function testLogout() { $session = new Session(); $controller = new AuthenticationController($session); $controller->logoutAction(); $this->assertFalse(isset($_SESSION['username'])); } }

require 'PHPUnit/Framework.php'; class AuthContrTest extends PHPUnit_Framework_TestCase { public function testLogin() { $session = $this->getMock('Session'); $session->expects($this->once()) ->method('start'); $session->expects($this->once()) ->method('register') ->with('username', 'Stefan'); $controller = new AuthenticationController($session); $controller->loginAction(); } }

Take-Aways Stefan's

Stefan's Take-Aways