REST &.NET James Crisp.NET Practice Lead ThoughtWorks Australia

James Crisp

The Web

*-ilities

Scalability

Recoverability & Reliability

Security

Discoverability

How to bring to Web services?

Tunneling RPC URLs POX SOAP & WS-*

REpresentational State Transfer

REST contributes... the rationale behind the modern Web's software architecture Roy Fielding

Resources e.g. Person, Car, Post

Representations Bill Gates m

Addressability

Uniform Interface

GET POST HEAD PUT DELETE OPTIONS Support

GET GET /people/joe_citizen HTTP/1.1 Host: mysite.com Accept: application/xml

Response 200 OK Content-Type: application/xml Last-Modified: :00.. Joe Citizen 42 m

HEAD HEAD /people/joe_citizen HTTP/1.1 Host: mysite.com 200 OK Content-Type: application/xml Last-Modified: :00.. ETag: a32daf15-b33da2a4d Response

POST POST /people HTTP/1.1 Content-Type: text/xml Host: mysite.com.... Tina Jones 25 F

Response 201 CREATED Location: /people/tina_jones (optionally with body)

PUT PUT /people/tina_jones HTTP/1.1 Content-Type: text/xml Host: mysite.com.... Tina Jones 24 F

Response 200 OK Location: /people/tina_jones (optionally with body)

DELETE DELETE /people/joe_citizen HTTP/1.1 Host: mysite.com 200 OK Content-Type: application/xml joe_citizen Response

OPTIONS OPTIONS /people HTTP/1.1 Host: mysite.com 200 OK Allowed: GET,HEAD,POST Response

Status Codes

2xx = All good 200 – OK 201 – Created

3xx = Redirect 301 – Moved permanently 307 – Temporary redirect 304 – Not modified (ie, see cache)

4xx = Client error 400 – Bad request 401 – Unauthorized 403 – Forbidden 405 – Method not allowed 409 – Conflict

5xx = Server error 500 – Internal server error

Headers

Content-Type: text/html application/xml image/jpeg....

WWW-Authenticate: Authorization:

Last-Modified: If-Modified-Since: ETag: If-None-Match:

Location:

Describe your services?

URI Templates

Start URL + Links Tina Jones <link rel="history" href="/tjones/account_history"> <link rel="close" verb="delete" href="/tjones">

Microformats Tina Jones <link rel="transaction-search" href="account_history? from={date-from}& to={date-to}">

State Management Search google.com/ search?q=rest google.com/search?q=rest& start=10 Next Page Searching Searched More Results

Data Format?

XHTML Accounts <a rel="account_details" href="/tjones">Tina Jones.....

JSON { "account_name": "Tina Jones", "links": {"history": "/tjones/history"} }

Framework

Ordering Pizza

GET / HTTP/1.1 Host: epizza.com Content-Type: application/xml

Response 200 OK Location: Content-Type: application/xml Content-Length:... Welcome! <link rel="place-order" href="/orders" />

Let's see the menu! GET /menu HTTP/1.1 Host: epizza.com Content-Type: application/xml

200 OK Location: <link rel="place-order" href="/orders" /> Menu Response

Ordering time! POST /orders HTTP/1.1 Host: epizza.com Content-Type: application/xml Content-Length:...

201 Created Location: Content-Type:... <link rel="destination" href="/orders/413/address"> Place Order Response

Beer with that?

OPTIONS /orders/413 HTTP/1.1 Host: epizza.com 200 OK Allowed: GET, HEAD, POST, PUT

Add Beer POST /orders/413 HTTP/1.1 Host: epizza.com Content-Type: application/xml Content-Length:...

200 OK Location: Content-Type:... <link rel="destination" href="/orders/413/destination"> Response

Destination Address PUT /orders/413/address HTTP/1.1 Host: epizza.com Content-Type: application/xml Content-Length: Rue Rd Potts Point

Destination Response 200 OK Host: epizza.com Content-Type: application/xml Content-Length: Rue Rd Potts Point

200 OK Location: Content-Type:... GET /orders/413

Can we? OPTIONS /orders/413 HTTP/1.1 Host: epizza.com 200 OK Allowed: GET, HEAD

Too late!

Back at the ePizza Kitchen..

GET /orders

Implementation

Client var request = (HttpWebRequest) WebRequest.Create(URL); request.Method request.ContentType request.GetRequestStream() var response = (HttpWebResponse)request.GetResponse(); response.StatusCode response.Headers response.GetResponseStream()

Server

IHttpHandler public class RestHandler : IHttpHandler { public void ProcessRequest(HttpContext context) { context.Response.ContentType = "application/xml"; if (context.Request.HttpMethod == "GET") { context.Response.Write("... "); }

WCF REST [ServiceContract] public interface IPizzaService { [WebGet(UriTemplate="/orders/{orderId}")] [OperationContract] Order GetOrder(int orderId); }

Status codes? Headers? Links? Microformats?

ASP.NET MVC

Routing Table Controller Method ModelView

Routes In GlobalApplication : HttpApplication void RegisterRoutes(RouteCollection routes) { routes.MapRoute( "AddToOrder", "orders/{id}", new { controller = "Orders", action = "AddToOrder" }, new { httpMethod = new HttpMethodConstraint("POST")});... }

Controller public class OrdersController : Controller { public ActionResult AddToOrder(int id) { var order = Order.Load(id); var itemToAdd = CreateMenuItemFromRequest(); order.Items.Add(itemToAdd); order.Save(); // response.StatusCode = 200; return View(order); }

Model public class Order { public MenuItem[] Items { get {... }; } public Address DeliveryAddress { get; set; } }

View " /> <link rel="destination" href=...

MVC REST Wrinkles

See also... Slides & Code MVC RESTful Web Services

- web - bridge - web - defibrillator - padlocks - ws* stack - tunnel - fielding - bill gates - network plugs - speedometers - Petco explosion - letter - Eiffel tower - pizza restaurant - pepperoni pizza - corona - salad pizza boxes – REST book Image References

Questions?