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REST and WCF 3.5
Glen GordonDeveloper Evangelist, Microsofthttp://blogs.msdn.com/glengordon
Session Objectives
Provide you with an overview of RESTIllustrate the new webHttpBinding Show you how to create and consume REST services
Agenda
Life before RESTUnderstanding the WebSOAP ServicesWCF 3.0
REST Overview (including the REST Continuum)webHttpBinding OverviewPragmatic REST DemoPurist REST Demo
The Web in the real world
Everything (mostly) is URI addressableHTTP Verbs
GET - Most PrevalentPOST – Overloaded, Used for actionsPUT, DELETE – Largely Ignored
Representation Format – (X)HTMLHTTP Response Codes Stateless
SOAP Services (from 50,000 feet)
Typically overload POSTMessage body contains method information
Messages wrapped with a SOAP Envelope
WSDL describes SOAP serviceWS-* provides extended functionalityStandardized and interoperable Sample:
POST /ProductServices.svcHost: www.somesite.comSOAPAction: GetProduct…<soap:Envelope xmlns: … <soap:Body> <GetProduct xmlns: … <ProductId>1</ProductId> </GetProduct> </soap:Body></soap:Envelope>
WCF 3.0 HTTP Bindings
basicHttpBindingSOAP BindingConforms to WS-I Basic Profile 1.0 standards
wsHttpBindingSOAP BindingProvides extended functionality
ws-AtomicTransactionws-ReliableMessagingetc.
No “web-friendly” bindings
Agenda
Life before RESTUnderstanding the WebSOAP ServicesWCF 3.0
REST Overview (including the REST Continuum)webHttpBinding Overviewpragmatic REST Demopurist REST Demo
REST
Representational State Transfer (REST) is a style of software architecture for distributed hypermedia systems such as the World Wide Web
From Wikipedia.org
Representational State Transfer (REST) works on top of HTTP and takes advantage of URLs as a sort of "command line interface". In such an environment, one computer creates a URL defining a request from a second program or computer. Once received the second computer treats the URL as a command, processes it, and returns the results as an XML stream From osuosl.org
Foundations of REST
Everything* can be modeled as a resourceEvery resource can have one or more “names”Every resource can have one or more representationsResources are manipulated via the uniform interfaceLeverage HTTP features as recommended in the specs
Anatomy of an HTTP request
GET /ControlPanel/Blogs/postlist.aspx HTTP/1.1Accept: image/gif, … application/x-shockwave-flash, application/x-silverlight, */*
Accept-Language: en-US,zh-CN;…
Accept-Encoding: gzip, deflate
User-Agent: Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.0; SLCC1; .NET CLR 2.0.50727; .NET CLR 1.1.4322; Tablet PC 2.0; InfoPath.2; .NET CLR 3.5.21022; .NET CLR 3.0.04506; MS-RTC LM 8)
Host: blogs.msdn.com
Proxy-Connection: Keep-Alive
Verb URIHeaders
[optional] body
HTTP/1.1 200 OK
Proxy-Connection: Keep-AliveConnection: Keep-AliveContent-Length: 52535Expires: -1Date: Fri, 15 Feb 2008 00:52:40 GMTContent-Type: text/html; charset=utf-8Server: Microsoft-IIS/6.0…Cache-Control: no-cachePragma: no-cache
Anatomy of an HTTP response
Response code
Content-Type header
Headers
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Frameset//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-frameset.dtd"> <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"> <head> <title>Community Server Control Panel </title…
Resources
AnythingStatic objects (html files, images, etc)Entities that have a representationResults of queries & methods execution…
URIs
URIs
URL is an artifact of the readonly webhttp://localhost/MyApplication/images/img.jpg C:\inetpub\wwwroot\MyApplication\images\img.jpg
The Web does not distinguish between static & dynamic
URI is a true identifierhttp://localhost/MyApplication/proc?id=256http://localhost/MyApplication/proc/256http://localhost/MyApplication/proc/lightsabre
URIs partition the application spaceTransparent vs opaque
REST Continuum
Well Constructed URIs
HTTP VerbsGET – FetchPUT – Update / InsertDELETE – DeletePOST – Append
Standard Representations
RESTfullness
Hi-
REST
Lo-
REST
POST to 1 URI OKQuerystrings OKHTTP Verbs
GET – FetchPOST - Overloaded
POX OK
Purists Pragmatists
Agenda
Life before RESTUnderstanding the WebSOAP ServicesWCF 3.0
REST Overview (including the REST Continuum)webHttpBinding Overviewpragmatic REST Demopurist REST Demo
webHttpBinding
New “web-friendly” WCF Binding in Fx 3.5Allows for the development of RESTful servicesWorks across REST ContinuumHTTP and HTTPS Transports OnlyDoes not use SOAP envelopesWebMessageEncoding
JSONXMLBinary
[WebGet] and [WebInvoke]
Indicate the HTTP Method for the operationWebGet – Don’t make me write itWebInvoke – All verbs other than GET (Method parameter takes in the name of the Verb)
Other ParametersBodyStyle – Indicates whether the Request / Response are wrapped or notRequestFormat – Json or XmlResponseFormat – Json or XmlUriTemplate – Covered in a minute…
UriTemplate
String that allows you to define the structure of the URI, as well as to define “Holes”
The “Holes” are variablesYou Bind the template with parameters to fill the holes
{productId} hole / variable gets bound to productId parameter in operation
[OperationContract][WebGet(UriTemplate=“product/{productId}")]Product GetProduct(int productId);
Hole
webHttpBinding Endpoint Behaviors
Endpoint Behaviors - extend run-time behavior for an endpoint
webHttp - enables the Web programming model for a WCF serviceenableWebScript – ASP.NET AJAX friendly endpoint behavior
Aligns nicely with ASP.NET AJAX clientSubClasses webHttpProvides ASP.NET AJAX proxy generationOnly supports GET and overloaded POSTDoes not support UriTemplates
DEMO
Pragmatic (ASP.NET AJAX-Friendly) REST Services
enableWebScript endpoint behaviorConsuming with an ASP.NET AJAX Client
Purist REST ServiceswebHttp endpoint behaviorConsuming with an AJAX Client
Summary
REST principles borrow from principles of the webArchitectures vary with regard to adherence to REST principleswebHttpBinding supports architectures across the REST continuum
enableWebScript Productivity features for ASP.NET AJAX applicationsImposes limitations
webHttp – Provides ability to implement services that adhere to strictest of standards
Resources
Steve Maine's Blog - http://hyperthink.net/blog/Justin Smith's Blog - http://blogs.msdn.com/justinjsmithHTTP Programming with WCF and the .NET Framework 3.5http://msdn.microsoft.com\msdnmag\issues\08\01\WCFinOrcas
© 2008 Microsoft Corporation. All rights reserved. Microsoft, Windows, Windows Vista and other product names are or may be registered trademarks and/or trademarks in the U.S. and/or other countries.
The information herein is for informational purposes only and represents the current view of Microsoft Corporation as of the date of this presentation. Because Microsoft must respond to changing market conditions, it should not be interpreted to be a commitment on the part of Microsoft, and Microsoft cannot guarantee
the accuracy of any information provided after the date of this presentation. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION.
Glen GordonDeveloper Evangelist, Microsofthttp://blogs.msdn.com/glengordon
