Abu's blog

Tutorial Windows Communication Foundation (WCF) - ServiceContract & OperationContract - Attributes

2009-07-20T13:07:00Z

ServiceContractAttribute

Name and Namespace - The name and namespace are the optional attibutes. Default name is same as the contract type and namespace is http://tempuri.org. It is always recommondable to use Namespace to specify proper namespace which remove the conflict of the datatype/contract.
CallbackContract - Return contract in a two-way (duplex) conversation.
HasProtectionLevel and ProtectionLevel - Specifies whether all messages supporting the contract have a explicit ProtectionLevel value.
Default ProtectionLevel is ProtectionLevel.None.
ConfigurationName - The name of the service element in the configuration file to use.
SessionMode - This is to specify whether the contract requires a binding that supports sessions.

OperationContractAttribute

Name: The name of an operation is part of a service contract. Default is the method name.
Action: The send message dispatches to the method for the operation based on action.
ReplyAction: To specify the reply message
IsOneWay: Specifies whether the operation is one directional that an does not return a reply message. This is commonly used for notification service.
ProtectionLevel
IsInitiating: Specifies if the operation is the intial operation in a session.
IsTerminating: Specifies if the session will be terminated after the operation
AsyncPattern: To asynchronously using a Begin/End method pair

RESTful WCF Service

2009-07-08T18:10:00Z

RESTful WCF Services works by identifing the Resources & Action from Uniform Resource Identifiers (URIs).

A RESTful web service is called by a unique URI to refer a resource and HTTP verb is to define actions to the resource.

HTTP Method - Verb
GET – Fetch
PUT – Update/Insert
DELETE – Delete
POST – Append

webHttpBinding is a new WCF binding in Fx 3.5 to develop RESTful services. This does not use SOAP envelopes HTTP and HTTPS Transports. It supports XML, JSON and Binary (streams).

WebServiceHost is a specialized SerivceHost which automatically configures address, binding, contract.
If no endpoint is defined, WebServiceHost automatically creates a default endpoint. WebServiceHost adds WebHttpBehavior and disables the HTTP Help page and the Web Services Description Language (WSDL) GET functionality.

[WebGet] And [WebInvoke] attribute
Binds a WCF operation to URI space and HTTP method Indicate the HTTP Method for the operation

WebGet – No method is require

WebInvoke – All verbs other than GET (Method parameter takes in the name of the Verb)

Other attributes can mentioed
BodyStyle – Indicates whether the Request/ Response are wrapped or not
RequestFormat – Json or Xml
ResponseFormat – Json or Xml

UriTemplate – Rich binding to URI UriTemplate String that allows define the structure/pattern of the URI

"M" is "Oslo" Modeling Language Language > Tools - Query Analyzer or SQL Server Management Sudio for SQL and “Intellipad” for "M"

2009-01-17T13:12:00Z

The evolution of programming languages have been categorized as 1GL, 2GL, 3GL, 4GL....E.g. Machine Language -> Assembly Language -> C / Fortran -> SQL / Focus 4GL. The evolution of these languages are towards Low level language to High Level language.

In 1995, I stated learning computer languages. First I learned C, just after going through Fundamentals of Computer. In my first Academic project using C, I spent lots of time only for writing thousands lines of code. During this period I have gone through System Analysis and Design - where I learned about how to translate / transform the business application into computer systems [application]. Then I learned C++ and OOP, it was too nice experience, where I could compare the whole thing to real life cases. But it was amazing when I came to know SQL - real 4GL... Writing SQL Statement is about "WHAT" not "HOW" [With few exceptions - Query Hints etc.]. Using SQL generally few lines code computes the values from a set of collections as the resultset/output. Then I started my career with one of the biggest giant - Petroleum Company in India using Sybase and Power Builder. Here I got opportunity to work with all my favourite technologies.

About the future or coming technologies, termed as NEXT GEN Application, I expressed very early in one of my post published on September 15, 2005 Real Challenge to the architect for architecting and designing for FUTURE application development’s method.

That time I was thinking that DSL, ORM, Modeling language were dream and will be goals for the language developer.

Now Microsoft comes up to this with a fantastic way!!!

In last version - .NET Framework 3.5, we got LINQ, LINQ to SQL, LINQ to XML, LING to Object.... Here we focused more on the Entities, Visual Studio writes the code for data manipulation using SQL/XPath all underlying technologies... we stopped thinking about implementation to map the data source to object classes for .NET to some extents. Here we got LINQ to SQL, LINQ to XML and so on so...

This is not the "Full Stop" ("."). Along with more advancement, Microsoft came up with "M". It is "Oslo" Modeling Language which is a declarative language for working with data in more readable way for Structuring the the data as well as for querying too. It's not about how data is stored or accessed, even not by implementation of specific technology.

M builds on three basic concepts: values, types, and extents.

A value is the data which follows the rule
A type describes a set of values.
An extent provides dynamic storage for values.

M has been designed to map the relational model too. Using “Intellipad” tool of “Oslo”, model the data and the corresponding T-SQL statements generated by the compiler. Here “M”->SQL translates “M” "modules" to SQL "schemas."

Oslo - Microsoft Official Site

2009-01-14T07:22:00Z

Microsoft’s forthcoming modeling platform is OSLO. More on http://www.microsoft.com/soa/products/oslo.aspx

"Oslo" realted Downloads are available here http://msdn.microsoft.com/en-us/oslo/cc748654.aspx

"Oslo" SDK download - Download the "Oslo" SDK October 2008 CTP

WCF Tutorial & Hands On Lab (HOL) - Tutorial/Lab # 01 (b) - Client Applications for IIS Hosted Service

2009-01-11T17:10:00Z

Download - The Service and Client Application

Tutorial Windows Communication Foundation (WCF) - Basics of WCF - Contracts

2009-01-11T04:40:00Z

Windows Communication Foundation (WCF) application is divided two layers namely Services and Clients

The WCF services can be exposed in different ways through Web, Windows Service, Self Hosting [Running Console Application]. The Endpoint [Which is having the Address, Binding, Contract(ABC)] is definded to expose service or consume it.

In our sample code so far we have developed Console Based application for both Service and Client Applications; then we have deployed the serive in IIS 6.0 in Windows Server 2003 in the first set of applications. The next set of applications are Web Applications.

For developing a WCF Service we have gone through steps
A. Sevice Layer
Step I - Designing Contracts
Step II - Service Hosting and Selecting Bindings
Step III - Configuring for Hosting the Service

B. Client Application
Step IV - Based on Sevice creating Proxy for invoking the Service

Now we will discuss futher in details.

We have looked that in both application, we have the one common thing, that is Endpoint includes the Service Contact, Address and Binding; only service hosting and client applications are different. The service contact is first item to be designed fo a Service.

A service contract is all about:

Grouping of operations
Signature of the operations for exchanging Mesages
Data types of these messages.
Protocols and serialization formats for communicating the messages

The contact is a set of specific messages organized into basic message exchange patterns (MEPs), such as request/reply, one-way, and duplex

One Way - Datagram-style delivery
Request-Reply - Immediate Reply on same logical thread
Duplex - Reply later and on backchannel (callback-style)

Three Types of Contracts
Service Contract - Operations, Behaviors and Communication Shape
Data Contract - Defines Schema and Versioning Strategies
Message Contract - Allows defining application-specific headers and unwrapped body content

All the contracts are defined on .NET application as CLR types and and on the wire it represents as XML format - WSDL/XSD/SOAP. This is implemented through Attributes. Here the details for all the types

Service
The Service and operations defines in a service through ServiceContract and OperationContract attrubutes.
Mapping: CLR types -> Web Services Description Language (WSDL)

Data
Describes a data structure using DataContract and DataMember attributes.
Mapping: CLR types -> XML Schema Definition (XSD)

Message
Defines the structure of the message on the wire using MessageContract, MessageHeader, MessageBody
Mapping: CLR types -> Simple Object Access Protocol (SOAP) messages.

Fault/Exception
For any CLR exceptions defined as fault contract using FaultContract attribute and the fault's CLR Type converts to SOAP faults.
Mapping: CLR types -> SOAP faults

WCF Tutorial & Hands On Lab (HOL) - Tutorial/Lab # 01 (b) - Hosting with IIS

2009-01-09T10:46:00Z

Now after creating "Hello World" most easy Service we will very happy to see by getting access throug a browser to access WSDL file and can be used in any other application by adding Service Reference.
Yes, we can access it just like to .asmx web service through .svc file. To host one service using IIS 6.0 - Windows Server 2003, we have to map .svc file ISAPI extention. Here is the the .SVC, Web.config files to download

SOA in the Real World

2009-01-08T06:16:00Z

This is one of my most interesting eBook which gives the real concepts of SOA. I am here to share this... Click on the book's image to download

A2Z WCF Hands On Lab (HOL) - Tutorial/Lab # 01 (a) - Metadata Exchange - WSDL

2009-01-05T11:45:00Z

The metadata is to describe how to interact with the service's endpoints. We could generate Proxy class for the Client as well as it updates the .config files[App.config/Web.config] for the Client Application.
For example Svcutil.exe could automatically generated client code for accessing the service..
Trough Visual Studio 2008/2005 with WCF extension, we can "Add Service Reference" which does the entire necessary task for us.

For is purpose it is the following code added to the Service Code.

using System.ServiceModel.Description;

ServiceMetadataBehavior svcMetaBehav = new ServiceMetadataBehavior();
svcMetaBehav.HttpGetEnabled = true;
svcHost.Description.Behaviors.Add(svcMetaBehav);

The WSDL of this service looks like as following:

<wsdl:binding name="BasicHttpBinding_IMyFirstService" type="i0:IMyFirstService">

<soap:binding transport="http://schemas.xmlsoap.org/soap/http" />

<wsdl:operation name="MyFirstMethod">

<soap:operation soapAction="http://KolkataNET.WCF.HOL/IMyFirstService/MyFirstMethod" style="document" />

<wsdl:input>

<soap:body use="literal" />

</wsdl:input>

<wsdl:output>

<soap:body use="literal" />

</wsdl:output>

</wsdl:operation>

</wsdl:binding>

<wsdl:service name="MyFirstService">

<wsdl:port name="BasicHttpBinding_IMyFirstService" binding="tns:BasicHttpBinding_IMyFirstService">

<soap:address location="http://abu:8080/WCFKolkataNET/HOL/MyService" />

</wsdl:port>

</wsdl:service>

WCF A2Z Hands On Lab (HOL) - Tutorial/Lab # 01 (a) - Client Application

2009-01-04T12:04:00Z

Step 5. Create New Console Project for creating Client Application the Service - Start running the Service when you generate the Proxy of the Service

5.1- Added Service Reference of the created Service

5.2- Created Proxy Class of the created Service - In service explorer click on show all files then a set of files will be showing which are auto generated, the proxy class file is here Reference.cs

5.3 This also generates the service binding details in App.config file

5.3 Auto generated Binding Details of the service in App.config file

<binding name="BasicHttpBinding_IMyFirstService" closeTimeout="00:01:00"

openTimeout="00:01:00" receiveTimeout="00:10:00" sendTimeout="00:01:00"

allowCookies="false" bypassProxyOnLocal="false" hostNameComparisonMode="StrongWildcard"

maxBufferSize="65536" maxBufferPoolSize="524288" maxReceivedMessageSize="65536"

messageEncoding="Text" textEncoding="utf-8" transferMode="Buffered"

useDefaultWebProxy="true">

<readerQuotas maxDepth="32" maxStringContentLength="8192" maxArrayLength="16384"

maxBytesPerRead="4096" maxNameTableCharCount="16384" />

<transport clientCredentialType="None" proxyCredentialType="None"

realm="" />

</security>

</binding>

</basicHttpBinding>

</bindings>

5.3 Auto generated End Point of the service in App.config file

<endpoint address="http://abu:8080/WCFKolkataNET/HOL/MyService" binding="basicHttpBinding"

bindingConfiguration="BasicHttpBinding_IMyFirstService" contract="MyFirstServiceClient.IMyFirstService"

name="BasicHttpBinding_IMyFirstService" />

</client>

5.4 Code in Prorgarm.cs

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Runtime.Serialization;

using System.ServiceModel;

namespace KolkataNETWCFHelloWorld

{

class Program

{

static void Main(string[] args)

{

EndpointAddress endPointAddr = new EndpointAddress("http://abu:8080/WCFKolkataNET/HOL/MyService");

MyFirstServiceClient clientProxy = new MyFirstServiceClient(new BasicHttpBinding(), endPointAddr);

string strResponse = clientProxy.MyFirstMethod();

Console.WriteLine(string.Format("Response from MyFirstService: {0}", strResponse));

Console.WriteLine();

Console.ReadLine();

}

Run the Client Application

WCF A2Z Hands On Lab (HOL) - Tutorial/Lab # 01 (a) - Service

2009-01-04T05:41:00Z

Step 1. Created one Console Project

Step 2. Created one Project in the same Solution IMyFirstService.csproj for declaring/designing Service contact

2.1- Added reference to System.ServiceModel

using System;

using System.Runtime.Serialization;

using System.ServiceModel;

namespace KolkataNETWCFHelloWorld

{

[ServiceContract(Namespace="http://KolkataNET.WCF.HOL")]

public interface IMyFirstService

{

[OperationContract]

string MyFirstMethod();

}

2.2 Design Simple Service Contract with one

[ServiceContract(Namespace="http://KolkataNET.WCF.HOL")]

public interface IMyFirstService

2.3 Design Simple Operation [Method/Function] using Attribute [OperationContract] by declaring the method name MyFirstMethod

Step 3. Created one Project in the same Solution MyFirstService.csproj for declaring/designing Service

3.1- Added reference to System.ServiceModel

using System;

using System.Runtime.Serialization;

using System.ServiceModel;

namespace KolkataNETWCFHelloWorld

{

public class MyFirstService : IMyFirstService

{

public string MyFirstMethod()

{

return string.Format("Hello World. Welcome KolkataNET!!!");

}

3.2 Design Simple Service implementing the above service Contract

public class MyFirstService : IMyFirstService

3.3 Design Simple Operation [Method/Function]

public class MyFirstService : IMyFirstService

{

public string MyFirstMethod()

{

return string.Format("Hello World. Welcome KolkataNET!!!");

}

Step 4. Modified the initial main Console Project to Self Host the Service

4.1- Added reference to System.ServiceModel - For hosting the service and exposing MEX - Metadata Exchange of the Service

using System;

using System.Runtime.Serialization;

using System.ServiceModel;

using System.ServiceModel.Description;

namespace KolkataNETWCFHelloWorld

{

class Program

{

static void Main(string[] args)

{

Uri svcBaseAddress = new Uri("http://abu:8080/WCFKolkataNET/HOL");

ServiceHost svcHost = new ServiceHost(typeof(MyFirstService), svcBaseAddress);

svcHost.AddServiceEndpoint(

typeof(IMyFirstService),

new BasicHttpBinding(),

"MyService");

ServiceMetadataBehavior svcMetaBehav = new ServiceMetadataBehavior();

svcMetaBehav.HttpGetEnabled = true;

svcHost.Description.Behaviors.Add(svcMetaBehav);

svcHost.Open();

Console.WriteLine("<ENTER> to stop the service - MyFirstService");

Console.WriteLine();

Console.ReadLine();

svcHost.Close();

}

4.2 Defining Base Address to host the Service

Uri svcBaseAddress = new Uri("http://abu:8080/WCFKolkataNET/HOL");

ServiceHost svcHost = new ServiceHost(typeof(MyFirstService), svcBaseAddress);

svcHost.AddServiceEndpoint(

typeof(IMyFirstService),

new BasicHttpBinding(),

"MyService");

4.3 Allowing to expose MEX of the Service

ServiceMetadataBehavior svcMetaBehav = new ServiceMetadataBehavior();

svcMetaBehav.HttpGetEnabled = true;

svcHost.Description.Behaviors.Add(svcMetaBehav);

4.3 Running the service until <ENTER> key has been pressed

svcHost.Open();

4.4 Closing the service when <ENTER> key has been pressed

svcHost.Close();

Running the Service - now we will create client to call it

Download Code - A2Z WCF Hands On Lab (HOL) - WCF Tutorial/Lab # 01- Service and Client Application

2009-01-03T06:23:00Z

Here is the code...

Click to Download

This is my first post for WCF HOL. I will be posting series of Lab Sessions with code and explanations for the whole series. I have noticed in one UG Session people who don't have any WCF backround but who are familiars of ASP.NET/.NET for them this series will be useful as a tutorial with practical.

Step by step I will be covering all the possible aspects of WCF. Same time I will be covering the SOA / Service based real life application scope especially for Connected and Distributed systems.

Please note that in the sample application every where I have used abu - which is my machine name, now for your case this will be your machine name

In Service Code
Uri svcBaseAddress = new Uri(http://abu:8080/WCFKolkataNET/HOL); // Change "abu" by your machine name

In Client Code
EndpointAddress endPointAddr = new EndpointAddress(http://abu:8080/WCFKolkataNET/HOL/MyService); // Change "abu" by your machine name

ASP.NET AJAX Client Libraries Webcast from Rob Bagby

2008-12-25T04:57:00Z

This series of Webcast includes A2Z[complete] ASP.NET AJAX Client Libraries - calling Web services, object-oriented development, creating controls, creating behaviors, and tips and tricks for development

WCF Services from ASP.NET AJAX

ASP.NET AJAX Client Library

REST in WCF

2008-12-23T14:26:00Z

The series blog post on REST in WCF

REST in WCF - Part I (REST Overview)

REST in WCF - Part II (AJAX Friendly Services, Creating The Service)

REST in WCF - Part III (AJAX Friendly Services, Consuming The Service)

REST in WCF - Part IV (HI-REST - Exposing a service via GET - Configuring the service)

REST in WCF - Part V (HI-REST - Exposing a service via GET - The ServiceContract and Implementation)

REST in WCF - Part VI (HI-REST - Consuming our GET service via AJAX)

REST in WCF - Part VII (HI-REST - Implementing Insert and Update

REST in WCF - Part VIII (HI-REST - Implementing Delete)

REST in WCF - Part IX - Controlling the URI

REST in WCF - Part X - Supporting Caching and Conditional GET

Url Rewriting using WCF

2008-12-22T21:26:00Z

One of my interesting thing is "URL Rewriting". The first time I have implemented it through implementing HTTPHandler using .NET 1.1. Same concept I have applied to a Document Management Service [DMS] project to PUT the document and GET the document by an .ASMX WebService. There I added verb * using wild charater in IIS 6.0 as well as added <httpHandler> node in web.config. Then we got in different way in .NET 2.0. Finally this time we got using URITemplate, WebGet, WebInvoke in WCF 3.5 SP1.

The UriTemplate class provides methods for working with sets of URIs that share a common structure for URL Rewriting.
As this follows based on the URL pattern comprises left portion of URI which is fixed and rest is dynamic where certain parameter is getting manipulated or changed to request a page. System.UriTemplate provides runtime support for URI template syntax.
UriTemplate is to manipulate parameters using ByName and ByPosition.
[WebGet] - supports HTTP GET method
WebOperationContext provides easy access to Web specifics (e.g., headers, status codes)
[WebInvoke] supports other HTTP methods; POST is default method

http://blogs.msdn.com/endpoint/archive/2008/08/22/rest-in-wcf-part-ix-controlling-the-uri.aspx

http://weblogs.asp.net/jgalloway/archive/2007/05/02/mix07-wcf-adding-system-uritemplate-webget-and-webinvoke.aspx

Corresponding to previous version's URL concept the available resources are in

http://msdn.microsoft.com/en-us/library/ms972974.aspx

http://weblogs.asp.net/scottgu/archive/2007/02/26/tip-trick-url-rewriting-with-asp-net.aspx

http://www.simple-talk.com/dotnet/asp.net/a-complete-url-rewriting-solution-for-asp.net-2.0/

WAW!!! What a serie of blog posts for "Covariance and Contravariance" - C# Future...

2008-12-16T18:46:00Z

So nicely step by step blogged by Eric Lippert for "Covariance and Contravariance" as "Fabulous Adventures In Coding"

Covariance and Contravariance, Part Eleven: To infinity, but not beyond

Immutability in C# Part Three: A Covariant Immutable Stack

Covariance and Contravariance in C#, Part Ten: Dealing With Ambiguity

Covariance and Contravariance in C#, Part Nine: Breaking Changes

Covariance and Contravariance in C#, Part Eight: Syntax Options

Covariance and Contravariance in C# Part Seven: Why Do We Need A Syntax At All?

Covariance and Contravariance in C#, Part Six: Interface Variance

Covariance and Contravariance In C#, Part Five: Higher Order Functions Hurt My Brain

Covariance and Contravariance in C#, Part Four: Real Delegate Variance

Covariance and Contravariance in C#, Part Three: Method Group Conversion Variance

Covariance and Contravariance in C#, Part Two: Array Covariance

Covariance and Contravariance in C#, Part One

C# Dynamic - CSharp's new feature of the coming version 4.0

2008-12-15T17:50:00Z

Very good resources for the coming version...

Sam Ng

Dynamic in C# Part One
Dynamic in C# Part Two

Chris Burrows

Eric Lippert

PDC

TL16: The Future of C#
- Anders Hejlsberg
TL10: Deep Dive: Dynamic Languages in .NET
- Speaker: Jim Hugunin
TL11: An Introduction to Microsoft F#
- Speaker: Luca Bolognese
TL12: Future Directions for Microsoft Visual Basic
- Speaker: Paul Vick and Lucian Wischik
TL44 IronRuby: The Right Language for the Right Job
- Speaker: John Lam
TL46: Microsoft Visual C# IDE: Tips and Tricks
- Dustin Campbell
TL54: Natural Interop with Silverlight, Office and Python
- Alex Turner
TL57: A Panel on the Future of Programming Languages
- G. Bracha, D.Crockford, A. Hejlsberg, E. Meijer, W.Schulte, J. Siek

"What NEXT?" - Visual Studio 2010 and with C# 4.0 and VB.NET 10.0 (Oslo)

2008-11-29T18:19:00Z

"What's Next?" - Everybody is interested to know about new and upcoming things. While I purchase new thing, I could not wait to use. Previously I was curious to know abour Whidbey, Orcas, WinFx ( Indigo, Avalon)... Next???

Now it is the case for Oslo too.

Now after PDC 2008, may many of us come to know about Visual Studio 2010.

"10" - this one very significant number for football player or hockey player; only the most important player are getting No. 10 as their jersey number.

Yes, this time, it is "10" - Visual Studio 2010, VB.NET 10, Visual Studio 10 is the NEXT.

Here are some very useful links related to this.

http://blogs.msdn.com/kirillosenkov/archive/2008/11/20/links-about-visual-studio-2010-and-c-4-0.aspx

http://weblogs.asp.net/pgielens/archive/2008/10/27/the-future-of-c-4-0.aspx

http://code.msdn.microsoft.com/csharpfuture

http://code.msdn.microsoft.com/csharpfuture/Wiki/View.aspx?title=Home&version=4

http://blogs.msdn.com/bclteam/archive/2008/11/04/what-s-new-in-the-bcl-in-net-4-0-justin-van-patten.aspx

C# Language Evolution - Features of C# 4.0

2008-11-29T06:27:00Z

C# Language Enhancement

C# 3,0 LINQ

C# 3.0 and LINQ With Language Extention

C# Dynamic Language Enhancement

C# 4.0 can be found on the Downloads page. The CSharpDynamic samples include several projects showing how to use Dynamic with Office, IronPython and other technologies. There is also a covariance and contravariance example, and an example show how to use the new IDynamicObject interface to create native C# objects that can be called dynamically.

The document New Features in C# 4.0 is a high level description of the additions to the C# language, and the samples are designed to show off the new language features, particularly around the dynamic scenario.

Application Architecture Pocket Guides

2008-11-26T05:27:00Z

Application Architecture Pocket Guides http://blogs.msdn.com/jmeier/archive/tags/AppArch/default.aspx