Creating Clean Code with AOP

/** * Security Aspect

* @aspect */class SecurityAspect {

protected $policies;

International PHP Conference, Mainz 2010

Robert Lemke

Create Clean Code with Aspect-Oriented Programming

Mittwoch, 13. Oktober 2010

Robert Lemkechief architect of TYPO3 Phoenix and FLOW3

co-founder of the TYPO3 Association

34 years old

lives in Lübeck, Germany

1 wife, 1 daughter, 1 espresso machine

likes drumming


= PHP 5.3 Full Stack Application Framework


OOP Object-Oriented Programming

AOP Aspect-Oriented Programming

MVC Model View Controller

POPO Plain Old PHP Object

DI Dependency Injection DRY

YAGNI

CoC

TDD

YAA


Create Clean Code with AOP International PHP Conference, Mainz 2010

/** * Creates a new post * * @param \F3\Blog\Domain\Model\Post $newPost A fresh Post object which has not yet been * added to the repository * @return void */public function createAction(\F3\Blog\Domain\Model\Post $newPost) { if ($this->policyService->isGranted($this->currentUser, __CLASS__, __METHOD__) { $this->blog->addPost($newPost); $this->flashMessageContainer->add('Your new post was created.'); $this->systemLogger->log('A new post was created.', LOG_INFO); $this->notificationService->notify('A new post was created.', '[email protected]'); } else { $this->systemLogger->log('Someone tried to create a post.', LOG_WARNING); throw new \F3\FLOW3\Security\Exception\AccessDeniedException('Tried to create.'); } $this->redirect('index');}



AOPMittwoch, 13. Oktober 2010


Aspect-Oriented Programmingprogramming paradigm

separates concerns to improve modularization

OOP modularizes concerns into objects

AOP modularizes cross-cutting concerns into aspects



/** * Creates a new post * * @param \F3\Blog\Domain\Model\Post $newPost A fresh Post object which has not yet been * added to the repository * @return void */public function createAction(\F3\Blog\Domain\Model\Post $newPost) { $this->blog->addPost($newPost); $this->flashMessageContainer->add('Your new post was created.'); $this->redirect('index');}



Concerns?



ConcernsSeparation of Concerns

group features and behavior into manageable parts

have a specific purpose and business to take care of

Cross-Cutting Concerns

are the party poopers who want to have a say in everything



Cross-Cutting ConcernsLogging

Security

Persistence

Global Business Logic

Dirty Hacks



We don't want infrastructure codein our models.



We want to unit-test even cross-cutting concerns



We want to centralize security-related code



AOP Lingo



AspectPart of the application where cross-cutting concerns are implemented

In FLOW3 aspects are classes annotated with @aspect



Join PointIs a single point in the call graph

Method Execution

Exception

Represents an event, not a location



PointcutA set of join points where advices could be executed

can be composed

can be named



AdviceAction to take at a join points defined by the point cut


Inspiring people toshareHitchhiker's Guide to FLOW3

DEMO



Kinds of AdviceAdvice types supported by FLOW3:

@before@afterreturning@afterthrowing@after@around



Pointcut Designatorsmethod(F3\MyPackage\MyClass->myMethod())class(F3\MyPackage\MyClass)within(F3\MyPackage\MyInterface)classTaggedWith(someTag)methodTaggedWith(anotherTag)setting(Demo.Stuff.SomeSetting = "yeah, do it")ffiilter(F3\MyPackage\MyCustomFilterImplementation)



Runtime Evaluationsevaluate(coffee.kind == "Arabica")



Compound Pointcuts

! /**! * @around method(.*Controller->(new|create|edit|update|delete)Action()) && ⏎ !methodTaggedWith(anybodyMayAccessThis)! */! public function interceptMethodCalls($joinPoint) {

...}



DEMO



FLOW3's AOP implementationbased on proxy classes

unlike with most pre-processors line numbers stay the same

no scaffolding

0 Lines of generated code which need to be maintained by you

fast (on the second hit)



Progress

FLOW3 1.0.0



Further ReadingFLOW3 Websitehttp://flow3.typo3.org

FLOW3 Downloadhttp://flow3.typo3.org/downloadgit://git.typo3.org/FLOW3/Distributions/Base.git

TYPO3 Forgehttp://forge.typo3.org

Further Readinghttp://flow3.typo3.org/about/principles/further-reading



Questions

Email: [email protected]: http://robertlemke.de/blogTwitter: @t3rob

Slides: http://slideshare.net/rlmp


Creating Clean Code with AOP

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