What is Web API

What is Web API and why to use it ?

Asp.Net Web API is a framework for building HTTP services that can be consume by a broad range of clients including browsers, mobiles, iphone and tablets. It is very similar to ASP.NET MVC since it contains the MVC features such as routing, controllers, action results, filter, model binders, IOC container or dependency injection. But it is not a part of the MVC Framework. It is a part of the core ASP.NET platform and can be used with MVC and other types of Web applications like Asp.Net WebForms. It can also be used as an stand-alone Web services application.

Why Asp.Net Web API (Web API) ?

Today, a web-based application is not enough to reach it's customers. People are very smart, they are using iphone, mobile, tablets etc. devices in its daily life. These devices also have a lot of apps for making the life easy. Actually, we are moving from the web towards apps world.

So, if you like to expose your service data to the browsers and as well as all these modern devices apps in fast and simple way, you should have an API which is compatible with browsers and all these devices.

For example twitter,facebook and Google API for the web application and phone apps.

Web API is the great framework for exposing your data and service to different-different devices. Moreover Web API is open source an ideal platform for building REST-ful services over the .NET Framework. Unlike WCF Rest service, it use the full featues of HTTP (like URIs, request/response headers, caching, versioning, various content formats) and you don't need to define any extra config settings for different devices unlike WCF Rest service.

Web API Features

1. It supports convention-based CRUD Actions since it works with HTTP verbs GET,POST,PUT and DELETE.
2. Responses have an Accept header and HTTP status code.
3. Responses are formatted by Web API’s MediaTypeFormatter into JSON, XML or whatever format you want to add as a MediaTypeFormatter.
4. It may accepts and generates the content which may not be object oriented like images, PDF files etc.
5. It has automatic support for OData. Hence by placing the new [Queryable] attribute on a controller method that returns IQueryable, clients can use the method for OData query composition.
6. It can be hosted with in the applicaion or on IIS.
7. It also supports the MVC features such as routing, controllers, action results, filter, model binders, IOC container or dependency injection that makes it more simple and robust.

Why to choose Web API ?

1. If we need a Web Service and don’t need SOAP, then ASP.Net Web API is best choice.
2. It is Used to build simple, non-SOAP-based HTTP Services on top of existing WCF message pipeline.
3. It doesn't have tedious and extensive configuration like WCF REST service.
4. Simple service creation with Web API. With WCF REST Services, service creation is difficult.
5. It is only based on HTTP and easy to define, expose and consume in a REST-ful way.
6. It is light weight architecture and good for devices which have limited bandwidth like smart phones.
7. It is open source.

Difference Between Http Services

Difference between WCF and Web API and WCF REST and Web Service

The .Net framework has a number of technologies that allow you to create HTTP services such as Web Service, WCF and now Web API. There are a lot of articles over the internet which may describe to whom you should use. Now a days, you have a lot of choices to build HTTP services on .NET framework. In this article, I would like to share my opinion with you over Web Service, WCF and now Web API. For more information about Web API refers What is Web API and why to use it ?.

Web Service

1. It is based on SOAP and return data in XML form.
2. It support only HTTP protocol.
3. It is not open source but can be consumed by any client that understands xml.
4. It can be hosted only on IIS.

WCF

1. It is also based on SOAP and return data in XML form.
2. It is the evolution of the web service(ASMX) and support various protocols like TCP, HTTP, HTTPS, Named Pipes, MSMQ.
3. The main issue with WCF is, its tedious and extensive configuration.
4. It is not open source but can be consumed by any client that understands xml.
5. It can be hosted with in the applicaion or on IIS or using window service.

WCF Rest

1. To use WCF as WCF Rest service you have to enable webHttpBindings.
2. It support HTTP GET and POST verbs by [WebGet] and [WebInvoke] attributes respectively.
3. To enable other HTTP verbs you have to do some configuration in IIS to accept request of that particular verb on .svc files
4. Passing data through parameters using a WebGet needs configuration. The UriTemplate must be specified
5. It support XML, JSON and ATOM data format.

Web API

1. This is the new framework for building HTTP services with easy and simple way.
2. Web API is open source an ideal platform for building REST-ful services over the .NET Framework.
3. Unlike WCF Rest service, it use the full featues of HTTP (like URIs, request/response headers, caching, versioning, various content formats)
4. It also supports the MVC features such as routing, controllers, action results, filter, model binders, IOC container or dependency injection, unit testing that makes it more simple and robust.
5. It can be hosted with in the application or on IIS.
6. It is light weight architecture and good for devices which have limited bandwidth like smart phones.
7. Responses are formatted by Web API’s MediaTypeFormatter into JSON, XML or whatever format you want to add as a MediaTypeFormatter.

To whom choose between WCF or WEB API

1. Choose WCF when you want to create a service that should support special scenarios such as one way messaging, message queues, duplex communication etc.
2. Choose WCF when you want to create a service that can use fast transport channels when available, such as TCP, Named Pipes, or maybe even UDP (in WCF 4.5), and you also want to support HTTP when all other transport channels are unavailable.
3. Choose Web API when you want to create a resource-oriented services over HTTP that can use the full features of HTTP (like URIs, request/response headers, caching, versioning, various content formats).
4. Choose Web API when you want to expose your service to a broad range of clients including browsers, mobiles, iphone and tablets.

Choosing which technology to use

The following table describes the major features of each technology.

 

WCF	ASP.NET Web API
Enables building services that support multiple transport protocols (HTTP, TCP, UDP, and custom transports) and allows switching between them.	HTTP only. First-class programming model for HTTP. More suitable for access from various browsers, mobile devices etc enabling wide reach.
Enables building services that support multiple encodings (Text, MTOM, and Binary) of the same message type and allows switching between them.	Enables building Web APIs that support wide variety of media types including XML, JSON etc.
Supports building services with WS-* standards like Reliable Messaging, Transactions, Message Security.	Uses basic protocol and formats such as HTTP, WebSockets, SSL, JQuery, JSON, and XML. There is no support for higher level protocols such as Reliable Messaging or Transactions.
Supports Request-Reply, One Way, and Duplex message exchange patterns.	HTTP is request/response but additional patterns can be supported throughSignalRand WebSockets integration.
WCF SOAP services can be described in WSDL allowing automated tools to generate client proxies even for services with complex schemas.	There is a variety of ways to describe a Web API ranging from auto-generated HTML help page describing snippets to structured metadata for OData integrated APIs.
Ships with the .NET framework.	Ships with .NET framework but is open-source and is also available out-of-band as independent download.

Use WCF to create reliable, secure web services that accessible over a variety of transports. Use ASP.NET Web API to create HTTP-based services that are accessible from a wide variety of clients. Use ASP.NET Web API if you are creating and designing new REST-style services. Although WCF provides some support for writing REST-style services, the support for REST in ASP.NET Web API is more complete and all future REST feature improvements will be made in ASP.NET Web API. If you have an existing WCF service and you want to expose additional REST endpoints, use WCF and the WebHttpBinding.