A resource orientated framework using the DI/AOP/REST Triangle

DI, AOP and REST are powerful patterns that developers should have in their tool belts. Akihito’s open source BEAR.Sunday framework goes one step further and uses them as the basis for strong architectural design for large scale PHP applications.
With very few components of its own, BEAR.Sunday is a fantastic example of how a framework can be built using existing components and libraries from other frameworks, yet offer even further simplicity beauty and power by holding on to these 3 core design patterns.

phpnw13
http://conference.phpnw.org.uk/phpnw13/schedule/akihito-koriyama-richard-mcintyre/

joindin
http://joind.in/talk/view/9302

Transcript

1. A resource orientated framework using the DI /AOP/REST Triangle
2. About Us • Akihito Koriyama • A Tokyo based freelance PHP architect • BEAR.Sunday lead, Aura PHP member • Richard McIntyre • Manchester / leeds based freelance PHP developer • BEAR.Sunday contributor, Lithium member
3. About Us • Akihito Koriyama • A Tokyo based freelance PHP architect • BEAR.Sunday lead, Aura PHP member • Richard McIntyre • Manchester / Leeds based freelance PHP developer • BEAR.Sunday contributor, Lithium member
5. BEAR.Sunday is an application framework. But it offers no libraries. (We have good stuff)
6. instead, it offers three object frameworks.
7. What is a framework ?
8. “imposes a set of design constraints on end-user code.”
11. 3.hypermedia framework
12. DI AOP REST
13. DI Benefits • Dependency Inversion Principle • Clear separation of object instantiation and object usage • Object delivery
14. DIP • Code should depend on things that are at the same or higher level of abstraction • High level policy should not depend on low level details
15. “The principle of dependency inversion is at the root of many of the benefits claimed for object- oriented technology. Its proper application is necessary for the creation of reusable frameworks”
16. Ray.DI Dependency Injection Framework
17. /** * @Inject */ public function __construct(RenderInterface $renderer) { ... 1.annotate at injection point class RendererModule extends AbstractModule { protected function configure() { $this->bind('RenderInterface') ->to('HalRenderer') ->in(Scope::SINGLETON); } $injector = Inject::create([new RendererModule]]; 2 bind abstraction to concretion 3.create an injector
18. /** * @Inject */ public function __construct(RenderInterface $renderer) { ... 1.annotate at injection point class RendererModule extends AbstractModule { protected function configure() { $this->bind('RenderInterface') ->to('HalRenderer') ->in(Scope::SINGLETON); } $injector = Inject::create([new RendererModule]]; 2. bind abstraction to concretion 3.create an injector
19. /** * @Inject */ public function __construct(RenderInterface $renderer) { ... 1.annotate at injection point class RendererModule extends AbstractModule { protected function configure() { $this->bind('RenderInterface') ->to('HalRenderer') ->in(Scope::SINGLETON); } $injector = Inject::create([new RendererModule]]; 2 bind abstraction to concretion 3.create an injector
20. $user = $injector->getInstance('UserInterface'); 4. Get an object graph from the $injector User Renderer Renderer Interface depends A B
21. QSPDFEVSBM PCKFDU
    PSJFUOFE DPNQJMBUJPO SVOUJNF Implement the structure, not a procedure
22. class RendererModule extends AbstractModule { protected function configure() { $this ->bind('RenderInterface') ->to('HalRenderer') ->in(Scope::SINGLETON); } } Only use concrete classes in compilation
23. Only abstraction in runtime /** * @Inject */ public function __construct(RenderInterface $renderer) {
24. DI Best practice “Your code should deal directly with the Injector as little as possible. Instead, you want to bootstrap your application by injecting one root object.”
25. Application = one root object
26. Application class
28. Application is root object retrieved with injector: $injector = Injector::create([new AppModule($context)]]; $app = $injector->getInstance(‘AppInterface’);
29. Application has dependency.
31. Dependencies have other dependencies Each object either contains or belongs to.
32. You get a application object graph. huge, but can be stored one single root value $app
33. "QQMJDBUJPO
    DBO
    CF
    TFSJBMJ[FE $app can be serialized and stored Injection is reused beyond requests.
34. $app Object i/f i/f Object i/f i/f Object Router Response JSON XM L 1st framework: DI Framework • annotations based DI framework w/ binding DSL • compilation / runtime separation • use only “plug/abstraction” at runtime • application a single large cached object • focus on structure not behavior
35. Aspect Oriented Programing
36. What is AOP? Cache Log Auth A programming paradigm that aims to increase modularity by allowing the separation of cross-cutting concerns
37. /** * @Cache */ public function onGet($id) { // ... $this->body = $stmt->fetchAll(PDO::FETCH_ASSOC); return $this; } class Post extends AppModel { public function newest() { $result = Cache::read('newest_posts', 'longterm'); if (!$result) { $result = $this->find('all'); Cache::write('newest_posts', $result, 'longterm'); } return $result; } }
38. M C I I AOP
39. M C Cache Cache is called by method invocation, If the cache is warm the model is never called. $obj->read(2); Miss !
40. Aspects Core Concern Cross Cutting Concern Separation
41. Rock Concert Example
42. interface MethodInterceptor { public function invoke(MethodInvocation $invocation); } $invocation->proceed(); // invoked method $object = $invocation->getThis(); // get source object $args = $invocation->getArgs(); // get arguments
43. class Transactional implements MethodInterceptor { public function invoke(MethodInvocation $invocation) { $object = $invocation->getThis(); $ref = new ReflectionProperty($object, 'db'); $ref->setAccessible(true); $db = $ref->getValue($object); $db->beginTransaction(); try { $invocation->proceed(); $db->commit(); } catch (Exception $e) { $db->rollback(); } } } `Transactional`interceptor Core Concern Cross Cutting Concern
44. class CacheInterceptor implements MethodInterceptor { public function invoke(MethodInvocation $invocation) { $obj = $invocation->getThis(); $args = $invocation->getArguments(); $id = get_class($obj) . serialize($args); $saved = $this->cache->fetch($id); if ($saved) { return $saved; } $result = $invocation->proceed(); $this->cache->save($id, $result); return $result; } } `Cache`interceptor Core Concern Cross Cutting Concern
45. 4JNQMZ
    BOOPUBUF UIFO
    DSFBUF
    ZPVS
    CJOEJOH
    #JOE
46. Layering by context • MVC, Is 3 enough ?
47. API Client
48. API Log Client Valid Auth
49. API Log !7BMJE BENJO %&-&5& Client Valid Auth
50. Aspect layering by context Model Cache Form Transaction Auth Validation
51. <?php class SandboxResourcePageIndexRay0000000071f9ab280000000033fb446fAop extends Sandbox\Resource\Page\Index implements Ray\Aop\WeavedInterface { private $rayAopIntercept = true; public $rayAopBind; public function onGet() { // native call if (!isset($this->rayAopBind[__FUNCTION__])) { return call_user_func_array('parent::' . __FUNCTION__, func_get_args()); } // proceed source method from interceptor if (!$this->rayAopIntercept) { $this->rayAopIntercept = true; return call_user_func_array('parent::' . __FUNCTION__, func_get_args()); } // proceed next interceptor $this->rayAopIntercept = false; $interceptors = $this->rayAopBind[__FUNCTION__]; $annotation = isset($this->rayAopBind->annotation[__FUNCTION__]) ? $this->rayAopBind >annotation[__FUNCTION__] : null; $invocation = new \Ray\Aop\ReflectiveMethodInvocation(array($this, __FUNCTION__), func_get_args(), $interceptors, $annotation); return $invocation->proceed(); } Under the hood: Method interception sub class is created in order enable this interception and keep type safety.
52. Runtime injection by aspect • method / parameter lookup • test friendly
53. 2nd framework: Aspect Oriented Framework • AOP alliance standard • Layering by context • Type safe • Runtime injection
55. Hypermedia framework for object as a service It allows objects to have RESTful web service benefits such as client-server, uniform interface, statelessness, resource expression with mutual connectivity and layered components.
56. class Author extends ResourceObject { public $code = 200; public $headers = []; public $body = []; /** * @Link(rel="blog", href="app://self/blog/post?author_id={id}") */ public function onGet($id) { ... // change own state return $this; } public function onPost($name) { $this->code = 201; // created return $this; } public function onPut($id, $name)
57. $user = $resource ->get ->uri('app://self/user') ->withQuery(['id' => 1]) ->eager ->request(); var_dump($user->body); // Array // ( // [name] => John // [age] => 15 //) echo $user; // <div id=”name”>John</div> // <div id=”age”>15</div> public function onGet($id) { $this[‘name’] = ‘John’; $this[‘age’] = 15; return $this; } User Profile Friend
58. $order = $resource ->post ->uri('app://self/order') ->withQuery(['drink' => 'latte']) ->eager ->request(); $payment = [ 'credit_card_number' => '123456789', 'expires' => '07/07', 'name' => 'Koriym', 'amount' => '4.00' ]; // Now use a hyperlink to pay $response = $resource->href('pay', $payment); echo $response->code; // 201 Hypermedia as the Engine of Application State
59. class Order extends ResourceObject { /** * * @Link(rel="pay", method="put", href="app://self/payment{?order_id,card_number,amount}") */ public function onPost($drink) { // data store here $this['drink'] = $drink; $this['order_id'] = $orderId; // created $this->code = 201; return $this; } Hypermedia as the Engine of Application State
60. Order Payment hyper reference: pay HyperMedia Driven API
61. The key of success of web • URI • Unified Interface • Hyperlink
62. • API is hub • API is core value API driven development DB Mobil e Web API Cloud Moc k URI API API
63. http://blog.8thlight.com/uncle-bob/2012/08/13/the-clean-architecture.html
64. Layered Resource UI Mobile Web Page Resource App script App Resource Entity
69. Performance • annotation ? dependency injection ? method interception ? DSL ? named parameter ? • Fast • cache all compiled object • http friendly architecture
70. Scale • “model proxy” pattern • ‘app://self/blog/entry’ can be anything. • contextual injection makes db scale easy
71. Hard spot / Soft spot • DI configure hardspot. QFS
    TZTUFN • Aop configure softspot, change on request
72. Connecting frameworks • DI - object as dependency • AOP - domain logic to application logic • Hypermedia - resource to resource
73. Abstraction frameworks • DSL • Annotation • URI • Interface • Aspects • Hypermedia
75. “Zen” framework
76. Thanks. Arigato http://www.flickr.com/photos/stevehoad/4678289858/ @mackstar @koriym