Building services for any client with ASP.NET Web APIDaniel RothSenior Program Manager3-036

How to reach more clients?

Browsers Devices Phones Tablets

? ? ? ?

App

How to make it scale?

Browsers Devices Phones Tablets

App

? ? ? ?

Leverage the web – build Web APIs

Browsers Devices Phones Tablets

Web APIApp

What is a Web API

An HTTP service

Designed for broad reach

Uses HTTP as an application protocol, not a transport protocol

A framework for creating HTTP services that can reach a broad range of clients including browsers and mobile devices

ASP.NET Web API

Microsoft Office 2013Unified communications Web API Powering Lync Web App 2013 and Lync 2013 for Windows Phone 8

Model

Lync Server 2013

REST API

Media Manager(Media State)

UI

Lync Web App

Lync for Windows

Phone

Lync for iPhone

Lync for iPad

Lync forAndroid

OutlookWeb App

JavaScript C#/XAML Objective C Java JavaScript

JavaScript C++/C C#

Language independentModifiable

Event-DrivenMobile-optimized (battery longevity, etc.)

Web friendly (JSON & XML)

Implements the Lync signaling endpoint business logic

Shields Apps from protocol chattiness.

Keeps up with the full state to deal with client disconnection and aggregates notifications. Client App can sync the information it needs

at its own pace.

Abstracts protocol complexity and provides access to all communication

& collaboration workloads

API

WEB

ROLE

APP SRT

P

UI

ASP.NET WEB API

MODEL

UCWA

Unified Communications Web API (UCWA)

First-class modern HTTP programming model

Easily map resources to URIs and implement the uniform interface of HTTP

Rich support for formats and HTTP content negotiation

Enable hypermedia and link generation

Separate out cross cutting concerns

Flexible hosting

Light-weight, testable, scales

ASP.NET Web API

Getting started with ASP.NET Web APIIncluded with ASP.NET MVC 4 and Visual Studio 2012Available as stand-alone NuGet packagesSupported on .NET 4 and laterDocumentation on http://www.asp.net/web-api Install the ASP.NET Fall 2012 Update preview (http://www.asp.net/vnext) to get the latest features

Your first Web API

Creating Web APIsDefine your routes (or just use the default one)

Create a new class that derives from APIControllerName your class {controller} + ControllerImplement your actions

routes.MapHttpRoute( name: "DefaultApi", routeTemplate: "api/{controller}/{id}", defaults: new { id = RouteParameter.Optional });

Web API dispatcherInvoke action

Action filters

Parameter binding

Select action Exception filters

Route to controller Formatting

HttpRequestMessage

HttpResponseMessage

Authorization filters

Web API dispatcherInvoke action

Action filters

Parameter binding

Select action Exception filters

Route to controller Formatting

HttpRequestMessage

HttpResponseMessage

Authorization filters

Implementing Web API actionsWeb API actions map to HTTP methodsPrefix your action name with the desired HTTP methodEx GetCustomer, PostComment, DeleteOrder, etc.

Use [HttpGet/Post/Put/Delete] if you prefer a different nameOverload actions based on the presence of data in the URI

Note: Action selection can also be done using the {action} route variable just like MVC

IEnumerable<Customer> Get() {…}Customer Get(int id) {…}

Web API dispatcherInvoke action

Action filters

Parameter binding

Select action Exception filters

Route to controller Formatting

HttpRequestMessage

HttpResponseMessage

Authorization filters

Web API dispatcherInvoke action

Action filters

Parameter binding

Select action Exception filters

Route to controller Formatting

HttpRequestMessage

HttpResponseMessage

Authorization filters

Action parametersSimple parameter types are taken from the URIRoute data, query parameters

Complex parameter types come from the body (only one)Configured MediaTypeFormatters (formatters) are used to deserialize the request body based on the content typeJSON, XML, and form–url–encoded supported by default

Override using [FromUrl], [FromBody], [ModelBinder], custom parameter bindingYou can always work with HttpRequestMessage directly

Parameter validationValidation is run on the bound parametersSpecify validation rules using DataAnnotations or custom validation logicValidation errors are accumulated in the ModelStateCheck ModelState.IsValidSend back validation errors to client using Request.CreateErrorResponse(ModelState)

Web API dispatcherInvoke action

Action filters

Parameter binding

Select action Exception filters

Route to controller Formatting

HttpRequestMessage

HttpResponseMessage

Authorization filters

Web API dispatcherInvoke action

Action filters

Parameter binding

Select action Exception filters

Route to controller Formatting

HttpRequestMessage

HttpResponseMessage

Authorization filters

Web API dispatcherInvoke action

Action filters

Parameter binding

Select action Exception filters

Route to controller Formatting

HttpRequestMessage

HttpResponseMessage

Authorization filters

Response formatting and content negotiationReturned object is serialized in the response body using configured formattersRequest indicates preferred format using the accept headerServer selects a format for the response based on the request, action return type, configured formattersYou can always just return HttpResponseMessage directly

Scaffolding an entity framework code-first based Web API

Web API dispatcherInvoke action

Action filters

Parameter binding

Select action Exception filters

Route to controller Formatting

HttpRequestMessage

HttpResponseMessage

Authorization filters

FiltersUsed to handle cross cutting concernsAction filters run before and after invoking an actionAuthorization filters run before model binding and are specifically for authorizing the userException filters handle generating responses for error cases in a centralized way

Configured globally, per controller, or per action as an attribute (ex [Authorize])

ASP.NET Web API ODataQuerySimply return IQueryable to enable OData query supportAdd an ODataQueryOptions parameter to manage the query yourself

PagingUse [Queryable(ResultLimit=10)] to limit the number of resultsAdd the new ODataMediaTypeFormatter to enable next links using the OData format

OData query and paging

ASP.NET Web API ODataFeaturesCRUD operationsQueryAtom and JSON formatsActionsModel builderService Document, $metadataInheritanceCollection properties

Coming post DecSelect, expandContainmentFunctionsChange setsNamed streamsOpen typesEtagsRecursive routing

Non-SQL data sources

Support as much query as you want

Lots of custom business logic

When to use ASP.NET Web API OData

WCF Data Services ASP.NET Web API OData

Architecture Interfaces Components

Server? Client? Server and Client Server only

Maturity Released Preview

OData coverage Full Partial, more coming

Flexibility Low High

Key requirements IQueryable -

Custom business logic Medium Easy

Formats OData only Any format

Untyped Yes No

HTTP request/response handling

Http Client

HttpClient

Handler

Host Http

Dispatcher

Http Serve

r

Message handlers Message handlers

Task<HttpResponseMessage> SendAsync(

HttpRequestMessage request,

CancellationToken cancellationToken)

Message handlers:

Flexible hosting

Supporting multiple clients

Web API

Single Page App

Single Page Application (SPA) with ASP.NET Web API

Supporting multiple clients

Web API

Single Page App

Windows Store App

Windows Phone App

Windows Store and Windows Phone clients

SummaryASP.NET Web API is a framework for building HTTP

services that can reach any clientIt’s great for building Azure hosted back ends for Windows Store

and Windows Phone apps

Try out the new Single Page Application, OData, Help Page, and Tracing support in the ASP.NET Fall 2012 Update preview

http://www.asp.net/web-api

http://aspnetwebstack.codeplex.com

Resources

Please submit session evals on the Build Windows 8 App or at http://aka.ms/BuildSessions

• Follow us on Twitter @WindowsAzure

• Get Started: www.windowsazure.com/build

Resources

Please submit session evals on the Build Windows 8 App or at http://aka.ms/BuildSessions

© 2012 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.