PHP Benelux - Build Restful API easily with Symfony

Build Restful API easily with Symfony Sarah Khalil - January
29th, 2016

Who am I? • Head of • Trainer & Developer
• Enjoying sharer Sarah Khalil @saro0h

What’s the plan?

What’s the plan? Back to basics 1

What’s the plan? Back to basics 1 How to do
it? 2

What’s the plan? Back to basics 1 Alternative tools 3
How to do it? 2

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 doesn’t know the system behind

Uniform interface (5/6) Each resource has its identiﬁer: the URI.
Each resource has its representation. Auto-descripted message: for instance, JSON = content-type header.

Code on demand (6/6) The client download some code and
executes it The server is not aware of what is happening anymore optional

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 =>
Links!

Symfony Full Stack JMSSerializerBundle FOSRestBundle BazingaHateoasBundle NelmioApiDocBundle

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

Response HTTP/1.1 200 OK Host: 127.0.0.1:8000 Content-Type: text/html; charset=UTF-8 <!DOCTYPE
html> <html lang="en"> <head>

Symfony\Component\HttpFoundation\Request 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; }

Events

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', ), ); } }

Event subscriber <tag name="jms_serializer.event_subscriber" type="AppBundle\MyClass" direction="serialization" format="json" 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 work with. • Response => Content-Type the media type of the response (html, json, png…).

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

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 Option 1 fos_rest: codes: 'Symfony\Component\Routing\Exception\ResourceNotFoundException': 404 'Doctrine\ORM\OptimisticLockException': HTTP_CONFLICT

fos_rest: view: exception_wrapper_handler: My\Bundle\Handler\MyExceptionWrapperHandler 1 Error handling Option 2

fos_rest: view: exception_wrapper_handler: My\Bundle\Handler\MyExceptionWrapperHandler 1 implements FOS\RestBundle\ViewExceptionWrapperHandlerInterface 2 Error handling
Option 2

fos_rest: view: exception_wrapper_handler: My\Bundle\Handler\MyExceptionWrapperHandler 1 implements FOS\RestBundle\ViewExceptionWrapperHandlerInterface 2 public function
wrap($data) { return new MyExceptionWrapper($data); } 3 Error handling Option 2

fos_rest: view: exception_wrapper_handler: My\Bundle\Handler\MyExceptionWrapperHandler Take example on the FOS\RestBundle\Util\ExceptionWrapper 1
implements FOS\RestBundle\ViewExceptionWrapperHandlerInterface 2 public function wrap($data) { return new MyExceptionWrapper($data); } 3 Error handling Option 2

Other features • Automatic generation of routes • Consistency •
Versioning • url • mime type And way more! 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 Expression Language

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

class CollectionRepresentation { private $resources; public function __construct($resources) { $this->resources
= $resources; } public function getResources() { return $this->resources; } }

"resources": { { "name": « Mercure Los Angeles" }, {
"name": "Novotel Mexico" }, }

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

"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" } }

Symfony Full Stack JMSSerializerBundle FOSRestBundle BazingaHateoasBundle NelmioApiDocBundle Guzzle

Symfony Full Stack JMSSerializerBundle FOSRestBundle BazingaHateoasBundle NelmioApiDocBundle Guzzle Communicate between
microservices

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

Authentication with multiple API’s

Service 1 Service 2 Client Frontend 2 Frontend 1 Service
3 Service 4

Workﬂow 1. The user authenticates [him|her]self on frontend 1 2.
Do some stuff 3. Then clicks on a link that brings him/ her to the frontend 2

Service 1 Service 2 Client Frontend 2 Frontend 1 Service
3 Service 4 GET /admin HTTP/1.1 User-Agent: curl/7.37.1 Host: 127.0.0.1:8000 Accept: */* Authorization: Bearer XXXXXX

Get the token In an authenticator, grab the Authorization header
value

Get the token public function createToken(Request $request, $providerKey) { $bearer
= $request->headers… }

Validate a token / Get a new one…

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 • …

FosHttpCacheBundle Keep it mind

Ease the usage of your API

Symfony Full Stack JMSSerializerBundle FOSRestBundle BazingaHateoasBundle NelmioApiDocBundle Documentation

Alternative to FOSRestBundle

https://api-platform.com/

http://tinyurl.com/sﬂiveparis

Thank you! @saro0h speakerdeck.com/saro0h/ github.com/saro0h/oauth-github Follow me on @catlannister Come
see us at the SensioLabs booth!

PHP Benelux - Build Restful API easily with Sym...

PHP Benelux - Build Restful API easily with Symfony

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