WebApp : A Beginner's Guide to REST API

0. HTTP

HTTP ?

L'HyperText Transfer Protocol, plus connu sous l'abréviation HTTP est un protocole de communication client-serveur développé pour le World Wide Web.Source : wikipedia.org

Requête HTTP ?

Méthode + UrlGET

POST PUT DELETE

http://www.google.fr

Url ?

Le sigle URL (Uniform Resource Locator) désigne une chaîne de caractères utilisée pour adresser les ressources du World Wide Web : document HTML, image, sons .…Source : wikipedia.org

Url ?

http://www.thecorneliusclub.com/app/courses/developpeur-web-101

Protocole

Sous-domaine

Nom de domaine

Nom de la ressource

Client HTTP ?

WGETcURL

Serveurs HTTP ?

1. HTTP & WebApp

Application web classique

Utilisateur InternetClient http

Serveur physique

http://thecorneliusclub.com Requête http

Requête http

SQL Document

Données

WebApp & backend (1)

App mobile

Website

Service tiers

Requête http

Backend 1

Backend 2

Backend 3

Requête http

JSON / XML

Requête http

JSON / XML

WebApp & backend (1)

App mobile

Website

Service tiers

Requête http

Backend 1

Backend 2

Backend 3

Requête http

JSON / XML

Requête http

JSON / XML

Impossible à

maintenir !

WebApp & backend (2)

App mobile

Website

Service tiers

Requête http

Backend

Requête http

JSON / XML

Requête http

JSON / XML

WebApp & backend (2)

App mobile

Website

Service tiers

Requête http

Backend

Requête http

JSON / XML

Requête http

JSON / XML

Architecture trop

complexe !

WebApp & backend (3)

App mobile

Website

Service tiers

Requête http

API

Requête http

JSON / XML

Requête http

JSON / XML

JSON / XML

API ?

An API, or Application Programming Interface, at its most fundamental level, is how software applications to talk to each other using the Internet. An API allows you to open up data and other digital resources, to public developers, businesses, or even between departments and locations within a company.Source : http://apievangelist.com

2. REST

REST ?

Representational state transfer (REST) is an abstraction of the architecture of the World Wide Web; more precisely, REST is an architectural style consisting of a coordinated set of architectural constraints applied to components, connectors, and data elements, within a distributed hypermedia system. REST ignores the details of component implementation and protocol syntax in order to focus on the roles of components, the constraints upon their interaction with other components, and their interpretation of significant data elements.Source : http://en.wikipedia.org

Client–server-

Stateless-

Cacheable-

Layered system-

Uniform interface

Architectural constraints

Uniform interface (1)

Identification of resourcesIndividual resources are identified in requests, for example

using URIs in web-based REST systems.

Manipulation of resourcesWhen a client holds a representation of a resource, including any metadata attached, it has enough information to modify

or delete the resource.

Uniform interface (2)

Self-descriptive messagesEach message includes enough information to describe how to

process the message.

HATEOASA REST client needs no prior knowledge about how to interact

with any particular application or server beyond a generic understanding of hypermedia.

3. Mise en pratique

REST & URLs (1)

/coursCollection d’éléments

REST & URLs (2)

/cours/webdesignElément d’une collection

REST & HTTP methods (1)

POSTGETPUTDELETE

CréerLireModifierSupprimer

REST & HTTP methods (2)

Ressource POST GET PUT DELETE

/cours Créer un nouveau cours

Liste de tous les cours

Modifier tous les cours

Supprimer tous les cours

/cours/webdesign ERROR

Afficher le cours

webdesign

Modifier le cours

webdesign

Supprimer le cours

webdesign

HATEOAS

/cours/webdesign/chapitresAssociations

Paramètres (1)

/cours?limit=10&offset=50Pagination

Paramètres (2)

/search?q=uxRecherche

4. Tools & Best Practices

Versioning

/v1/cours

Limiter les champs

/cours?fields=id,name

Format

JSON

HTTP codes (1)

200 OKResponse to a successful GET, PUT, PATCH or DELETE.

201 CreatedResponse to a POST that results in a creation. Should be combined with a

Location header pointing to the location of the new resource

204 No ContentResponse to a successful request that won't be returning a body (like a

DELETE request)

Source : http://www.vinaysahni.com/best-practices-for-a-pragmatic-restful-api

HTTP codes (2)

400 Bad Request The request is malformed, such as if the body does not parse

401 UnauthorizedWhen no or invalid authentication details are provided. Also useful to trigger an auth

popup if the API is used from a browser

403 ForbiddenWhen authentication succeeded but authenticated user doesn't have access to the

resource

404 Not FoundWhen a non-existent resource is requested

405 Method Not Allowed When an HTTP method is being requested that isn't allowed for the authenticated user

Source : http://www.vinaysahni.com/best-practices-for-a-pragmatic-restful-api

Error

HTTP Code AND message

Debug

https://chrome.google.com/webstore/detail/advanced-rest-client/

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5. Security

Merci pour votre attention.

Bibliographie (1)

Demystifying REST - Jeffrey Way http://code.tutsplus.com/tutorials/demystifying-rest--pre-58000

A Beginner's Guide to HTTP and REST - Ludovico Fischer http://code.tutsplus.com/tutorials/a-beginners-guide-to-http-and-rest--net-16340

RESTful API Design: Teach a Dog to REST - Brian Mulloy https://blog.apigee.com/detail/restful_api_design

Best Practices for Designing a Pragmatic RESTful API - Vinay Sahni http://www.vinaysahni.com/best-practices-for-a-pragmatic-restful-api

RESTful Web APIs - Sam Ruby, Michael Amundsen & Leonard Richardson http://www.amazon.fr/RESTful-Web-APIs-Leonard-Richardson-ebook/dp/B00F5BS966/ref=sr_1_5?