WCF vs Web API vs WCF REST vs Web Service (SOAP)

The .Net framework has a number of technologies that allow you to create HTTP services such as Web Service, WCF and Web API.

Web Service

  • It is based on SOAP and return data in XML form.

  • It support only HTTP protocol.
  • It is not open source but can be consumed by any client that understands xml.
  • It can be hosted only on IIS.

WCF

  • It is also based on SOAP and return data in XML form.

  • It is the evolution of the web service(ASMX) and support various protocols like TCP, HTTP, HTTPS, Named Pipes, MSMQ.
  • The main issue with WCF is its tedious and extensive configuration (see WCF Tutorial).
  • It is not open source but can be consumed by any client that understands xml.
  • It can be hosted with in the application or on IIS or using windows services.

WCF Rest

  • To use WCF as WCF Rest service you have to enable webHttpBindings.

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

Web API

  • This is the new framework for building HTTP services with easy and simple way.

  • 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)
  • 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.
  • It can be hosted with in the application or on IIS.
  • It is light weight architecture and good for devices which have limited bandwidth like smart phones.
  • 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

  • Choose WCF when you want to create a service that should support special scenarios such as one way messaging, message queues, duplex communication etc.

  • 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.
  • 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).
  • Choose Web API when you want to expose your service to a broad range of clients including browsers, mobiles, iphone and tablets.

Asp.net MVC vs Asp.net Web API

Asp.net MVC framework can return JSON data by using JsonResult and can also handle simple AJAX requests. Asp.net Web API is the new framework for building HTTP services with easy and simple way.

  1. Asp.Net MVC is used to create web applications that returns both views and data but Asp.Net Web API is used to create full blown HTTP services with easy and simple way that returns only data not view.

  2. Web API helps to build REST-ful services over the .NET Framework and it also support content-negotiation(it’s about deciding the best response format data that could be acceptable by the client. it could be JSON, XML, ATOM or other formatted data), self hosting which are not in MVC.

  3. Web API also takes care of returning data in particular format like JSON, XML or any other based upon the Accept header in the request and you don’t worry about that. MVC only return data in JSON format using JsonResult.

  4. In Web API the request are mapped to the actions based on HTTP verbs but in MVC it is mapped to actions name.

  5. Asp.Net Web API is new framework and part of the core ASP.NET framework. The model binding, filters, routing and others MVC features exist in Web API are different from MVC and exists in the new System.Web.Http assembly. In MVC, these featues exist with in System.Web.Mvc. Hence Web API can also be used with Asp.Net and as a stand alone service layer.

  6. You can mix Web API and MVC controller in a single project to handle advanced AJAX requests which may return data in JSON, XML or any others format and building a full blown HTTP service. Typically, this will be called Web API self hosting.

  7. When you have mixed MVC and Web API controller and you want to implement the authorization then you have to create two filters one for MVC and another for Web API since boths are different.

  8. Web API is light weight architecture and except the web application it can also be used with smartphone apps.

Asp.net Web API Features

Web API is the great framework for exposing your data and service to different-different devices. It is open source an ideal platform for building REST-ful services over the .NET Framework. Unlike WCF Rest service, it use the full features 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

  • It supports convention-based CRUD Actions since it works with HTTP verbs GET, POST, PUT and DELETE.
  • Responses have an Accept header and HTTP status code.
  • Responses are formatted by Web API’s MediaTypeFormatter into JSON, XML or whatever format you want to add as a MediaTypeFormatter.
  • It may accepts and generates the content which may not be object oriented like images, PDF files etc.
  • 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.
  • It can be hosted with in the application or on IIS.
  • 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 ?

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

Asp.net MVC Life Cycles

At a high level, life cycle is a sequence of steps or events used to handle some type of request or change of an application state.

1. Application life cycle – refers to the time when the application process starts to run in IIS (Application start) until the process stops (Application end).

2. MVC Request life cycle – the sequence of events that happens every time an HTTP request is handled by the application.

MVC Request life cycle

Asp.net MVC Request Life Cycle

Asp.net MVC Request Life Cycle

Routing: The entry point for every MVC Application begins with Routing. After the application receives the request, it uses URL Routing Module to handle the request. The routing module is responsible for matching the incoming urls with the routes defined in the application. All routes have an associated MVC Route Handler. If the request is matched with one of the routes defined into application, the MVC Route Handler executes and retrieves an instance of MVC HttpHandler.

Controller initialization: The MVC HttpHandler begins the process of initializing and executing a controller. MVC framework converts our routing data into a specific controller that handle the request. This is accomplished by Controller Factory and Activator. This is the step where dependency injection are resolved. The next major step after controller creation is action execution.

Action execution: A component called Action Invoker finds and selects an appropriate Action Method to invoke in our controller. Before the method is called, Model Binding takes place and it maps the data from HttpRequest to parameters into our Action Methods. Action Filters are called before and after the method creates an Action Result.

Result execution: MVC separates declaring of the result from executing the result. If the result is a View type, the View Engine is called and it’s responsible for finding and rendering our view. If the result it’s not a view, the ActionResult executes on it’s own.

HttpModules and HttpHandlers

From the developers point of view the difference between those are: one implements IHttpModule interface another implements IHttpHandler interface.

Module participates in the request processing of every request in order to change or add to it in some way.

Handler is responsible for handling the request and producing the response for specific content types.

MVC Grid Paging with EntityFramework or Stored Procedures

Here we’ll implement Custom Paging in webgrid in MVC4 application.
It is a very essential approach to use paging technique in applications where lot of data to be loaded from the database.

HomeController.cs

Index.cshtml

Custom paging

Or you can use PagedList to do the paging code.

Updated version using Stored Procedures on MyGit.

Katana & Owin – Part II

This tutorial shows how to host ASP.NET Web API in a console application, using OWIN to self-host the Web API framework.

The source to add sample Web API configuration:

Greeting.cs

GreetingContoller.cs

WCF with Windows authentication

I ran into this problem because I wanted a WCF service hosted in IIS 7.5/8 on a website that had Windows Authentication enabled.
The service configuration looks much simpler in the config file of the web application hosting the WCF service:

Server configuration:

Remember to set this to the WCF service:

Client configuration:

I ended up using basicHttpBinding as explained in the article . Client config is generated using “svcutil”.

SignalR

SignalR is an asynchronous signaling library for ASP.NET that helps you build real-time multi-user web applications.

You can start playing with it by getting it with NuGet:

Install-Package SignalR

SignalR is broken up into a few package on NuGet:

SignalR – A meta package that brings in SignalR.Server and SignalR.Js (you should install this)
SignalR.Server – Server side components needed to build SignalR endpoints
SignalR.Js – Javascript client for SignalR
SignalR.Client – .NET client for SignalR
SignalR.Ninject – Ninject dependeny resolver for SignalR.

If you just want to play and make a small up, start up Visual Studio 2010. First, make an Empty ASP.NET application, and install-package SignalR with NuGet, either with the UI or the Package Console.

Second, create a new default.aspx page and add a button, a textbox, references to jQuery and jQuery.signalR along with this script.

The /signalr/hubs endpoint exposes all the available hubs in the solution and lets you access their public methods. You will first need to initiate connection.

Entire page source below:

We have two choices of models with SignalR: low level using PersistentConnection or highlevel using Hub. Hubs expose public methods to the clients and raise callbacks on the clients. In most web-based scenarios, you will be utilizing hubs, which follow the publish-subscribe pattern. See Hubs for additional details.

When a connection between a web client and a server is made, SignalR will determine a suitable transport type based on your client capabilities. It will gracefully degrade so older browsers might get long-polling instead of the fancy WebSockets. The transport mode can have a significant impact on the performance of the app.

WebSockets (bidirectional stream)
Server Sent Events (push notifications from server to browser using DOM events)
Forever Frame (uses HTTP 1.1 chunked encoding to establish a single long-lived HTTP connection in a hidden iframe)
Long polling (hit the server hit the server hit the server hit the server hit server and hope something comes back with data)

We’ll use second approach based on Hubs. Simply create a class and inherit from an abstract Hub class.

When you want to distribute messages to your clients, you can do so using the Clients dynamic object. Any method that you call on Clients will raise a callback on the client. Furthermore, you can get access to the current client call id using Context.ConnectionId or Groups dynamic object which looks after groups management. To publish on a specific connection you can use Clients[“groupName”].method(params) or Clients[Context.ConnectionId].method(params).

Please check this link with a short demo with MVC3, signalR and backbone.js.

Live presentation from authors of SignalR can be found on channel9.

jQuery UI and autocomplete TextBox

This article demonstrates how to add autocomplete feature to asp.net TextBox, exposing autocomplete values via WebService.

The Autocomplete widget is one of the widgets provided in jQuery UI and provides suggestions while you type into the field. jQuery UI is a free widget and interaction library built on top of the jQuery JavaScript Library, that you can use to build highly interactive web applications.

First let’s create the webservice that will generate some random values.

As you see in comments, please make sure [System.Web.Script.Services.ScriptService] is not commented otherwise you’ll have issues.

Below the code that do our job:

System.Lazy and System.Lazy

One of the cool new feature inside the .Net 4.0 framework is System.Lazy and System.Lazy<T>. What System.Lazy brings to the table is a way to create objects which may need to perform intensive operations and defer the execution of the operation until it is 100% absolutely needed.

Lazy initialization occurs the first time the Lazy.Value property is accessed or the Lazy.ToString() method is called.

HostingAccount.cs

HostingAccountFactory.cs

 

As you can see using Lazy is easy and can be a very powerful tool in your tool chest. But like everything else, this feature of the framework is NOT meant for ever scenario, use it where it makes sense.