ZendCon 2015 - Build Restful API easily with Symfony

Build Restful API easily with Symfony Sarah Khalil - October
21st, 2015

Who I am? • Head of • Trainer & Developer
• Enjoying sharer • Contributor to

What is REST?

What is REST? • REpresentational State Transfer • Architecture (not
a protocol!) • Associated to Service Oriented Architecture • Management of resources

The 6 constraints of REST

Client - Server (1/6) • Separation of concerns. • Portability.

Stateless (2/6) • Based on HTTP. • Session has to
be held on the client side.

Cacheable (3/6) • Avoid useless requests.

Layered system (4/6) • The client requests a resource but
it doesn’t know the system behind.

Uniform interface (5/6) • Each resource has its identiﬁed: the
URI. • Each resource has its representation. • Auto-descripted message: if it’s JSON, the HTTP response has a content-type header saying.

Code on demand (6/6) • The client should be executing
some code coming from the server, to avoid more work on the server side.

HTTP Methods • GET • POST • PUT • PATCH
• DELETE • OPTIONS • CONNECT • HEAD

Restful API

Keep’em in mind • JSON, XML, HTML… • By developers
and for developers • Scalability • Latency • Security !

http://martinfowler.com

HATEOAS • Hypermedia as the engine of Application State •
Discoverability

Symfony Full Stack JMSSerializerBundle FOSRestBundle BazingaHateoasBundle NelmioApiDocBundle

Philosophy

Request GET /users HTTP/1.1 User-Agent: curl/7.37.1 Host: 127.0.0.1:8000 Accept: */*

Symfony\Component\HttpFoundation\Request

Response HTTP/1.1 200 OK Host: 127.0.0.1:8000 Connection: close X-Powered-By: PHP/5.6.3
Set-Cookie: PHPSESSID=ecdadm6o2d5v9ei0m181j8gh96; path=/ Cache-Control: no-cacheDate: Wed, 11 Feb 2015 23:42:50 GMT Content-Type: text/html; charset=UTF-8 X-Debug-Token: 32860d X-Debug-Token-Link: /_profiler/32860d <!DOCTYPE html> <html lang="en"> <head>

Symfony\Component\HttpFoundation \Response

HttpKernel

Symfony Full Stack JMSSerializerBundle FOSRestBundle BazingaHateoasBundle NelmioApiDocBundle Work with resources

Json/XML Object serialization deserialization

Conﬁguration • XML, YML and Annotation. • http://jmsyst.com/libs/serializer/master/reference • Helper
to serialize properties the way you need.

class DefaultController { public function indexAction() { $obj = new
\StdClass(); $obj->latitude = -33.87087; $obj->longitude = 151.225459; $data = $this->get(‘jms_serializer’) ->serialize($obj, ’json’); return new Response( $data, 200, array(‘Content-Type’=>’application/json’) ); } }

HTTP/1.1 200 OK Host: 127.0.0.1 X-Powered-By: PHP/5.6.3 Content-Type: application/json {
"latitude": -33.87087, "longitude": 151.225459 } Output

Exclusion policy /** * @JMS\ExclusionPolicy("all") */ class Product { /**
* @JMS\Expose() */ private $name; private $users; } • Visitor pattern • Object graph • Relations (xToMany)

Serializer handler • Speciﬁc needs • implements JMS\Serializer\Handler\SubscribingHandlerInterface • <tag
name="jms_serializer.subscribing_handler" />

public static function getSubscribingMethods() { return [ [ 'direction' =>
GraphNavigator::DIRECTION_SERIALIZATION, 'format' => ‘json', 'type' => ‘AppBundle\MyClass’, 'method' => ‘serialize', ], [ 'direction' => GraphNavigator::DIRECTION_DESERIALIZATION, 'format' => ‘json', 'type' => ‘AppBundle\MyClass', 'method' => ‘deserialize', ], ]; }

public function serialize( JsonSerializationVisitor $visitor, MyClass $object, array $type, Context
$context ) { $data = $object->toArray(); return $data; } public function deserialize(JsonDeserializationVisitor $visitor, $data) { $object = new AppBundle\MyClass($data); return $object; }

Event subscriber • http://jmsyst.com/libs/serializer/master/event_system • implements JMS\Serializer\EventDispatcher\EventSubscriberInterface <tag name="jms_serializer.event_subscriber" type="AppBundle\MyClass"
direction="serialization" format="json" method="onPostSerialize" />

serialization deserialization

Object serialization deserialization

Object serialization deserialization serializer.pre_serialize

Object serialization deserialization serializer.pre_serialize serializer.post_serialize

Json/XML Object serialization deserialization serializer.pre_serialize serializer.post_serialize

Json/XML Object serialization deserialization serializer.pre_serialize serializer.post_serialize serializer.pre_deserialize

Json/XML Object serialization deserialization serializer.pre_serialize serializer.post_serialize serializer.pre_deserialize serializer.post_deserialize

class PostSerializeMediaListener implements EventSubscriberInterface { public function onPostSerialize(ObjectEvent $event) {
$myObject = $event->getObject(); $event->getVisitor()->addData('newElementInJson', 'information’); } public static function getSubscribedEvents() { return array( array( 'event' => Events::POST_SERIALIZE, 'format' => ‘json', 'class' => ‘AppBundle\MyClass', 'method' => ‘onPostSerialize', ), ); } }

Other features • Serialization group • Versionning

Symfony Full Stack JMSSerializerBundle FOSRestBundle BazingaHateoasBundle NelmioApiDocBundle Setup your Symfony
application

Controller # app/config/config.yml fos_rest: view: view_response_listener: force sensio_framework_extra: view: {
annotations: false } /** * @View() */ public function getUsersAction() { … return $data; }

Content-Type negociation • Request => Accept • priorities of media-type(s)
that your application is ready to get. • Response => Content-Type • the media type of the response (html, json, png…).

Content-Type negociation • Priorities define the order of media types
as the application prefers: • Request: Accept text/json;q=0.9,*/*;q=0.8,text/html # app/config/config.yml fos_rest: format_listener: rules: - { path: '^/', priorities: ['json'], fallback_format: html } weighting

Request body converter • Decoder • ParamConverter # app/config/config.yml sensio_framework_extra:
request: { converters: true } fos_rest: body_converter: enabled: true /** * @ParamConverter("post", converter="fos_rest.request_body") */ public function updateAction(Post $post) { }

Validation

Validation (with the Symfony Validator component) Conﬁguration fos_rest: body_converter: enabled:
true validate: true validation_errors_argument: validationErrors

Validation (with the Symfony Validator component) Usage /** * @ParamConverter("post",
converter="fos_rest.request_body") */ public function putPostAction(Post $post, ConstraintViolationListInterface $validationErrors) { if (count($validationErrors) > 0) { // Handle validation errors } }

Param Fetcher

/** * @QueryParam( * name="sort", * requirements="(asc|desc)", * allowBlank=false, *
default="asc", * description="Sort direction" * ) * @RequestParam( * name="firstname", * requirements="[a-z]+" * ) * @QueryParam( * array=true, * name="filters", * requirements=@MyComplexConstraint * ) */ public function getArticlesAction(ParamFetcher $paramFetcher) {} http://mydomain.com/resources?sort=desc In $request->request ($_POST) fos_rest.param_fetcher_listener: true

/** * @QueryParam(name="page", requirements="\d+", default="1") */ public function getArticlesAction($page) {}
fos_rest.param_fetcher_listener: force

Error handling

Error handling (1/2) fos_rest: codes: 'Symfony\Component\Routing\Exception\ResourceNotFoundException': 404 'Doctrine\ORM\OptimisticLockException': HTTP_CONFLICT

Error handling (2/2) fos_rest: view: exception_wrapper_handler: My\Bundle\Handler\MyExceptionWrapperHandler implements FOS\RestBundle\ViewExceptionWrapperHandlerInterface public
function wrap($data) { return new MyExceptionWrapper($data); } Take exemple on FOS\RestBundle\Util\ExceptionWrapper

Other features • Automatic generation of routes • Consistency •
Versioning • url • mime type • Take a look at the documentation • http://symfony.com/doc/master/bundles/FOSRestBundle/index.html

Symfony Full Stack JMSSerializerBundle FOSRestBundle BazingaHateoasBundle NelmioApiDocBundle Unlock the level
3 of the Richardson’s model

HAL • Hypertext Application Language • _links - relations •
_embedded - related resource(s) • self • Speciﬁcations: http://stateless.co/hal_speciﬁcation.html

JSON API • Similar to HAL • meta - meta
info such as pagination… • links - Relations (xToOne - xToMany) • linked - Resource(s) linked • Speciﬁcations : http://jsonapi.org/format/

Conﬁguration • Annotation, XML and YML • Relies on Expression
Language (since Symfony 2.4)

/** * @Hateoas\Relation( * "self", * href = @Hateoas\Route( *
"get_notification", * absolute= true, * parameters = { * "id" = "expr(object.getId())", * "user" = "expr(service(‘security.context’).getToken().getUser().getUuid())" * } * ) * ) */ class Notification

Result { "id": 1, "_links": { "self": { "href": "http://domaine.name/users/eh1754329986/notiﬁcations/1/"
} } }

/** * … * @Hateoas\Relation( * "activity", * href =
"expr(‘/activity/'~object.getActivity().getId()", * embedded = "expr(object.getActivity())", * exclusion = @Hateoas\Exclusion(excludeIf = "expr(object.getActivity() === null)") * ) */ class Notification

Result { "id": 1, "_embedded": { "activity": { "id": 3,
"content": "Activity content", "_links": { "self": { "href": "/activities/3" } } } } }

Representation • Use representation to decorate your resource • Hateoas\Representation\PaginatedRepresentation
• And many more: https://github.com/willdurand/Hateoas/tree/master/src/Hateoas/Representation

"page": 1, "limit": 10, "pages": "100", "total": 1000, "_links": {
"self": { "href": "http://domain.name/notifcations?page=1&limit=10" }, "first": { "href": "http://domain.name/notifcations?page=1&limit=1" }, "last": { "href": "http://domain.name/notifcations?page=100&limit=1" }, "next": { "href": "http://domain.name/notifcations?page=2&limit=1" } }

Representation • Any representation you need ! • A class
with the properties you need. • Let the serializer do its job.

Symfony Full Stack JMSSerializerBundle FOSRestBundle BazingaHateoasBundle NelmioApiDocBundle Guzzle

Symfony Full Stack JMSSerializerBundle FOSRestBundle BazingaHateoasBundle NelmioApiDocBundle Guzzle Communicate between
micro services

Frontend Service 1 Service 2 Service 3 Service 4 Private
network Client

Guzzle Bundle • HTTP Client • Request • Response •
HTTPS • Error management • https://github.com/misd- service-development/guzzle- bundle • https://github.com/csarrazi/ CsaGuzzleBundle

Security

Authentication • Authorization header: Authorization: Bearer <access_token> • https://github.com/poledev/katas/tree/kata- authentication
• http://symfony.com/doc/current/cookbook/security/ api_key_authentication.html • Make it stateless!

Authorization • access_control • $this->get(‘security.authorization_checker’)->isGranted('ROLE_ADMIN') • {% if is_granted(‘ROLE_ADMIN’) %}
• Voter • ACL • …

FosHttpCacheBundle Keep it mind

One last thing

Symfony Full Stack JMSSerializerBundle FOSRestBundle BazingaHateoasBundle NelmioApiDocBundle Documentation

Oh I forgot to introduce you Lannister! @catlannister

http://tinyurl.com/sfcon2015

http://tinyurl.com/sﬂiveusa

Thank you! @saro0h speakerdeck.com/saro0h/ saro0h This is a zero guys!

ZendCon 2015 - Build Restful API easily with Sy...

ZendCon 2015 - Build Restful API easily with Symfony

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