create clean code with aop
DESCRIPTION
Slides from my talk at the International PHP Conference (Spring Edition) 2010 in Berlin.OOP helps us creating a clearly laid out and intuitive model of the reality by means of objects. However, concerns like security, logging or transactions need to be implemented virtually anywhere, resulting in scattered error-prone code. Aspect-oriented Programming separates these cross-cutting concerns from the rest of the code and lets you handle them in a well-known, central location.TRANSCRIPT
International PHP Conference, Spring Edition 2010
Robert Lemke
Create Clean Code with Aspect-Oriented Programming
Photo: Wolfgang Staudt
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
= 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
LLATIP
Create Clean Code with AOP IPC SE 2010, Berlin
/** * 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');}
Create Clean Code with AOP IPC SE 2010, Berlin
/** * 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->authorizationService->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); $this->flashMessageContainer->add('Access denied.'); } $this->redirect('index');}
Create Clean Code with AOP IPC SE 2010, Berlin
AOP
Create Clean Code with AOP IPC SE 2010, Berlin
Aspect-Oriented Programmingprogramming paradigm
separates concerns to improve modularization
OOP modularizes concerns into objects
AOP modularizes cross-cutting concerns into aspects
Create Clean Code with AOP IPC SE 2010, Berlin
/** * 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');}
Create Clean Code with AOP IPC SE 2010, Berlin
Concerns?
Create Clean Code with AOP IPC SE 2010, Berlin
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
Create Clean Code with AOP IPC SE 2010, Berlin
Cross-Cutting ConcernsLogging
Security
Persistence
Global Business Logic
Dirty Hacks
Create Clean Code with AOP IPC SE 2010, Berlin
We don't want infrastructure codein our models.
Create Clean Code with AOP IPC SE 2010, Berlin
We want to unit-test even cross-cutting concerns
Create Clean Code with AOP IPC SE 2010, Berlin
We want to centralize security-related code
Create Clean Code with AOP IPC SE 2010, Berlin
AOP Lingo
Create Clean Code with AOP IPC SE 2010, Berlin
AspectPart of the application where cross-cutting concerns are implemented
In FLOW3 aspects are classes annotated with @aspect
Create Clean Code with AOP IPC SE 2010, Berlin
Join PointIs a single point in the call graph
Method Execution
Exception
Represents an event, not a location
Create Clean Code with AOP IPC SE 2010, Berlin
PointcutA set of join points where advices could be executed
can be composed
can be named
Create Clean Code with AOP IPC SE 2010, Berlin
AdviceAction to take at a join points defined by the point cut
Inspiring people toshareHitchhiker's Guide to FLOW3
DEMO
Inspiring people toshareHitchhiker's Guide to FLOW3
Kinds of AdviceAdvice types supported by FLOW3:
@before@afterreturning@afterthrowing@after@around
Inspiring people toshareHitchhiker's Guide to FLOW3
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)
Inspiring people toshareHitchhiker's Guide to FLOW3
Runtime Evaluationsevaluate(coffee.kind == "Arabica")
Inspiring people toshareHitchhiker's Guide to FLOW3
Compound Pointcuts
! /**! * @around method(.*Controller->(new|create|edit|update|delete)Action()) && ⏎ !methodTaggedWith(anybodyMayAccessThis)! */! public function interceptMethodCalls($joinPoint) {
...}
Inspiring people toshareHitchhiker's Guide to FLOW3
DEMO
Inspiring people toshareHitchhiker's Guide to FLOW3
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)
Inspiring people toshareHitchhiker's Guide to FLOW3
Create Clean Code with AOP IPC SE 2010, Berlin
Progress
FLOW3 1.0.0
Create Clean Code with AOP IPC SE 2010, Berlin
Further ReadingFLOW3 Websitehttp://flow3.typo3.org
TYPO3 Forgehttp://forge.typo3.org
Further Readinghttp://flow3.typo3.org/about/principles/further-reading
http://bit.ly/GoodAOPArticle
Create Clean Code with AOP IPC SE 2010, Berlin
Questions
Email: [email protected]: http://robertlemke.de/blogTwitter: @t3rob
Feedback: http://joind.in/1743