Brijesh Choubey's Blog

Windows Workflow Foundation

2007-02-26T05:29:00.000-08:00

Workflow at its simplest is the movement of documents and/or tasks through a work process. More specifically, workflow is the operational aspect of a work procedure: how tasks are structured, who performs them, what their relative order is, how they are synchronized, how information flows to support the tasks and how tasks are being tracked. As the dimension of time is considered in Workflow, Workflow considers "throughput" as a distinct measure. Workflow problems can be modeled and analyzed using graph-based formalisms.

Business processes are set up by organizations to define precisely how they are to work.

Workflows are a way of defining business processes. They define the steps followed in a process, who carries out each step, and what are the inputs and outputs of each step.

A workflow is often seen as a precise definition of how business is conducted or how a business process proceeds. It defines the business process using a precise set of system terms - for example, roles, tasks, documents, transitions and so on. Most current workflow definition methods define those business processes that follow a precise set of steps.

WWF or WF is the built-in collaboration and workflow technology included in the .NET Framework of the Windows Vista operating system. WF is part of the Vista programming model formerly called WinFX and now called .NET Framework 3.0. To develop workflow applications, Visual Studio 2005 is required plus the Extensions for Windows Workflow Foundation.

From Wikipedia:

Windows Workflow Foundation (WF) is a Microsoft technology for defining, executing, and managing workflows. This technology is part of .NET Framework 3.0 and will be available natively in the Windows Vista operating system, and has been backported to the Windows XP and Windows 2003 Server operating systems. The .NET Framework 3.0 "workflow runtime" provides common facilities for running and managing the workflows and can be hosted in any CLR app domain.

A new XML-based language XAML is commonly used for declaring the structure of a workflow. However, the workflow may also be expressed in code using any .NET-targeted language (like C#).

Workflows comprise 'activities'. Developers can write their own domain-specific activities and then use them in workflows. The .NET Framework 3.0 Windows Workflow Foundation also provides a set of general-purpose 'activities' that cover several control flow constructs.

Windows Workflow Foundation is supported by a companion set of extensions to Visual Studio 2005. These extensions contain a visual workflow designer which allows users to design workflows, a visual debugger which enables the users to debug the workflow designed, and a project system which enables the user to compile their workflows inside Visual Studio 2005.

Here are some good articles to understand what is Windows Workflow Foundation in .NET 3,0 from a higher lever:

What Is Windows Workflow Foundation?

Get Ready for Windows Workflow Foundation

Windows Workflow Foundation at MSDN

Some interview questions related to WWF or WF are:
What is Windows Workflow Foundation?
What is a Workflow?.
What are different types of Workflow in Windows Workflow foundation?
When should we use a sequential workflow and when should we use state machine?
How do we create workflows using designer?
How do we specify conditions in Work flow?
How do you handle exceptions in workflow?
What is the use of XOML files?
Twist: - How can we serialize workflows?
How can we pass parameters to workflow?

Top 12 all time technical books for every Software Developer & Engineer

2007-01-30T01:28:00.000-08:00

Top 12 all time technical books for every Software Developer & Engineer

I found this article on Vishal Sharma's Blog on Startups, Technology, Telecom, Current Affairs very useful. The top 12 books listed here realy very important for every software developer or Engineer. I my self has read most of them but not all :)

The top 12 books listed here are:

Design Patterns: Elements of Reusable Object-Oriented Software by Erich Gamma, Richard Helm, Ralph Johnson, John Vlissides
Code Complete, Second Edition by Steve McConnell
The Mythical Man-Month: Essays on Software Engineering,
20th Anniversary Edition by Frederick P. Brooks
The Art of Computer Programming, Volumes 1-3 Boxed Set by Donald E. Knuth
The Pragmatic Programmer: From Journeyman to Master by Andrew Hunt, David Thomas
Unix Network Programming, Vol. 1 and II: The Sockets Networking API, Third Edition by W. Richard Stevens, Bill Fenner, Andrew M. Rudoff, Richard W. Stevens
Advanced Programming in the UNIX(R) Environment (2nd Edition) by W. Richard Stevens, Stephen A. Rago
Algorithms in C, Parts 1-5 : Fundamentals, Data Structures, Sorting, Searching, and Graph Algorithms (3rd Edition)
Modern Operating Systems (2nd Edition) by Andrew Tanenbaum
The Protocols (TCP/IP Illustrated, Volume 1 by W. Richard Stevens
Fundamentals of Database Systems (5th Edition)
by Ramez Elmasri, Shamkant B. Navathe
The Guru's Guide to Transact-SQL by Ken Henderson.

Null Coalescing Operator in C# 2.0

2006-07-10T02:15:00.000-07:00

Today while going through David Hayden's blog I found this "??" Null Coalescing Operator in C# 2.0.

This operator (null coalescing operator) is new in C# 2.0. The null coalescing operator provides inherent null-checking capabilities. The result of the expression is based on whether the first operand is null. If the first operand is not null, it is the result of the expression, otherwise, the result falls to the second operand. In other words, return the first value if not null, otherwise the second.

a ?? b is equivalent to a != null ? a : b.

To show an example of this operator. I created a new C# windows application wrote below code for Form_Load.

private void Form1_Load(object sender, EventArgs e)
{
int? a = null, b = 1;
int? x = a ?? b;
MessageBox.Show(x.ToString()); // x = 1
}

A couple of links on this are: Fritz Onion's blog and Oliver Sturm's blog .

.NET Framework 3.0

2006-06-28T04:11:00.000-07:00

WinFX is Now the .NET Framework 3.0

S. Somasegar describes the decision to rename WinFX to the .NET Framework 3.0. The comments and questions on this blog are interesting. Why does microsoft always comes up with some name and then changes that and I agree with Wasim Sadiq on Microsoft screwing up cool names.

Now one more question is .NET 3.0 = 2.0 ? It seems like taking existing .NET Framework 2.0 and adding WPF (Windows Presentation Foundation), WCF ( Windows Communication Foundation), WF (Windows Workflow Foundation) and WCS (Windows CardSpace) and calling it .NET Framework 3.0.

Unit Testing with VSTS

2006-06-12T08:57:00.000-07:00

I attended the MS Tech-Ed session on Unit Testing with Visual Studio Team System last friday. Unit testing .NET code is not something new. Developers have been doing unit testing of .NET code since .NET is out. To name a few .NET unit testing tools are :
1.NUnit
2.MbUnit
3.TestDriven.Net

With VSTS microsoft has integrated not only unit testing framework with .NET IDE but has added supports to other testing, such as functional and load testing. Code coverage and Static Code analysis tool (FxCop) are other tools which are available with VSTS.

There has been already a lot of talk about the pricing for VSTS and different flavours of Visual studio 2005. Professional version doesnot have any of the above mentioned tools, while VSTS for developers (VSTD) has unit testing, FxCop and Code Coverage but functional (web testing) and load testing tools are not available with this. To get functional (web) testing tool and load testing tool you will have to buy Visual Studio team suite or VSTS for testers.

Unit testing tool available with VSTS is very similar to NUnit with added features like you can right click on your method/class and create unit test. It will create a unit test and test project for you. You can go ahead and modify the unit test by setting proper values etc. Other features of this unit testing framework are that you can make your test data driven and can see the coverage of your tests using code coverage.

The thing I like about this unit testing framework integrated with .NET IDE is that I can use my unit tests for load testing and as well as for my subsiquent build verification tests. Since this unit tests are nothing but similar .NET projects I can store them in source safe and can have different versions of my unit tests.

Here is a good article on MSDN on unit testing walkthrough with visual studio team test .

BarCampPune coming up on 17th June...

2006-05-30T01:46:00.000-07:00

BarCamp is an ad-hoc un-conference born from the desire for people to share and learn in an open environment.

After the success of BarCamp at BarCampBangalore and BarCampMumbai it is coming to BarCamppune and I think it is going to be a greater success here. I am looking forward to this event and it is going to be a great fun.

Some useful articles on .NET 2.0

2006-05-23T02:22:00.000-07:00

1. Comparing Strings in .NET 2.0

Sometimes the seemingly simplest things turn out to be the most difficult. For example, one would think that comparing strings in a program would be simple. It turns out that things can get ugly very quickly, and prior to .NET 2.0 there wasn’t a foolproof way to eliminate the problem.

Here is a good article on Comparing Strings in .NET 2.0 . This article very well describes how to compare culture-invariant strings: strings that must compare identically regardless of the culture. This article takes the well known the "Turkish I" problem to explain how to Compare Culture-Invariant Strings in .NET 2.0.

2. New Memory Management Functions in .NET 2.0

This article talks about the new memory management functions in .NET 2.0. Several new memory management facilities have been added to .NET 2.0 to have more control on garbage collector and ability to check for sufficient memory. This article also talks about new garbage collector functionality.

3. Playing Sounds with .NET 2.0

The .NET 2.0 Framework Class Library includes a new class in the System.Media namespace, called SoundPlayer. SoundPlayer provides a simple interface for loading and playing a .wav file. This is a much nicer and more robust interface than the PlaySound interface that programmers used in previous versions and is described in Playing Simple Sounds.

4. NET Delegates: A C# Bedtime Story

A nice and good article on delegates in .NET 2.0. C# Bedtime story modified for 2.0.

5. Guidelines for Test-Driven Development

Find out how to incorporate Visual Studio Team System into test-driven development practices emphasized in Agile development methodologies.

What is the Maximum Page Size in SQL Server 2000?

2006-05-18T23:04:00.000-07:00

I have always read and also told others that 8060 is the maximum page size in SQL server 2000. Earliear when I had came accross this error "The total row size for table exceeds the maximum number of bytes per row (8060). Rows that exceed the maximum number of bytes will not be added." even if the row size in my create table script was slightly less than 8060, I used to think that SQL server requires some sapce for its overheads to store header etc. information.

Recently I came across this article What is the Maximum Page Size in SQL Server 2000? by Steve Jones. This article explains in detail where and how much space SQL server requires and also that maximum possible row size is in fact 8039.

Second Generation Agile Software Development

2006-03-28T19:22:00.000-08:00

Time to market constraints is pushing the development community to respond faster. Constant pressures to get things done faster are forcing us towards light weight and faster software development processes.

The field of software development is never shy of introducing new methodologies. While no agreement on what the concept of agile refers to exists, it has generated a lot of interest. The introduction of extreme programming method known as XP has been widely acknowledged as the starting point of various agile software development approaches.

Randy Miller, on MSF for Agile Software Development, has a post that examines the next generation of agile software development. He talks about "new" XP as second generation agile software development. He also talks about the “Chinese menu” approach to creating own second generation agile processes.

MSF for Agile Software Development Process Guidance is a scenario-driven, context-based, agile software development process that utilizes many of the ideas embodied in Team System.

These are two sites dedicated to agile software development Manifesto for Agile Software Development and Agile Alliance .

Practical Tips For Boosting The Performance Of Windows Forms Apps

2006-03-10T05:07:00.000-08:00

Practical Tips For Boosting The Performance Of Windows Forms Apps

This is a very good article on MSDN regarding performance of Windows Forms Applications. This article talks about:
1. Improving application startup time
2. Tuning up control creation and population
3. Improving painting performance
4. Rendering text and images
5. Efficient resource management

ASP.NET Best Practices for High Performance Applications

2006-02-21T06:35:00.000-08:00

This is a very good article on codeproject on ASP.NET best practices for high performance. This article explains following points:

1. Plan and research before you develop
2. String concatenation
3. Avoid round trips to the server
4. Save viewstate only when necessary
5. Use of session variables carefully
6. Use Server.Transfer
7. Use server controls when appropriate and avoid creating deeply nested controls
8. Choose the data viewing control appropriate for your solution
9. Optimize code and exception handling
10. Use a DataReader for fast and efficient data binding
11. Use paging efficiently
12. Explicitly Dispose or Close all the resources
13. Disable tracing and debugging
14. Precompiling pages and disabling AutoEventWireup
15. Use of stored procedures and indexes

Click here for the article.

ASP.NET 2.0 Page LifeCycle

2006-02-21T00:58:00.000-08:00

This chart was created by Leon Andrianarivony.

Static constructors in C#

2006-01-31T04:17:00.000-08:00

Some important point regarding static constructor in C# are :

1) The static constructor for a class executes before any instance of the class is created.
2) The static constructor for a class executes before any of the static members for the class are referenced.
3) The static constructor for a class executes after the static field initializers (if any) for the class.
4) The static constructor for a class executes at most one time during a single program instantiation
5) A static constructor does not take access modifiers or have parameters.
6) A static constructor is called automatically to initialize the class before the first instance is created or any static members are referenced.
7) A static constructor cannot be called directly.
8) The user has no control on when the static constructor is executed in the program.
9) A typical use of static constructors is when the class is using a log file and the constructor is used to write entries to this file.

Refrences:
1. c-sharpcorner
2. C# Language Specification
3. C# Programmer's Reference

C# Coding Standards

2005-12-09T05:04:00.000-08:00

Writing C# code is very easy now days. Having few months of experience and you can write a code, which compiles and runs. But developing a good application is not all about writing a code, which compiles and runs. Writing an efficient code or what we call "Production Quality" code requires having some coding standards in place.

These are the two C# coding standards which I liked. I am not saying everyone should use this but can have a look before making C# coding standards for their applications.

The C# coding standard as defined by Philips Medical Systems - Software / SPI

C# Coding Standards and Best Programming Practices On Code Project

2005 Nobel Prize for Physics

2005-10-04T07:25:00.000-07:00

This years noble prize for Physics have been awarded to Roy J Glauber and John L Hall of USA and Theodor W Hänsch of Germany.

Glauber : Theoretical description of the behaviour of light particles. (quantum theory of optical coherence)

Hall and Hänsch : Laser-based precision spectroscopy, that is, the determination of the colour of the light of atoms and molecules with extreme precision (optical frequency comb technique).

The Nobel Prize in Physics 2005

The Nobel Prize in Physiology or Medicine 2005

Setting accessibility for get and set of a Property in c# 2.0

2005-08-29T21:04:00.000-07:00

In c# 1.0 there was no way you can set the accessibility qualifiers for get or set inside a property.

C# 2.0 allows you to set different accessibility qualifiers for your get and set of a property. This feature is useful when you want to have different accessibility for your get and set.

public class Employee
{
private string _employeeName;

public string EmployeeName
{
public get { return _employeeName; }
protected set { _employeeName = value; }
}
}

Refrence Chris Breisch

ASP.NET Articles

2005-08-25T06:11:00.000-07:00

More than 100 good articles on ASP.NET are available at ftp online for ASP.NET developers.

Below are few articles, which are helpful in day-to-day programming.

IIS 7.0

A First Look at IIS 7.0

Componentization and ASP.NET integration are among the many new features coming up in the next version of Internet Information Services.

Visual Studio 2005

Customize Sites With Web Parts

Customizing site with web parts. The Visual Studio 2005 Toolbox features a tab called WebParts, which includes a dozen Web Part infrastructure controls that make up the Web Part framework.

ASP.NET 2.0

The New ASP.NET 2.0 Code-Behind Model

The New ASP.NET 2.0 Code-Behind Model. This article explains the working of new partial classes in ASP.NET 2.0.

Manage Users Fast

Add a new user to your system using ASP.NET 2.0's rich API for manipulating users and roles.

Master pages

ASP.NET 2.0's master pages can help you develop consistent Web apps without the additional overhead of include files, user controls, or third-party add-ins.

Techniques for managing client state

Working with and understanding how client state is used in your app is critical to putting a good design into practice. Examine three techniques for managing client state.

Manage Session State

Manage Session State on the Server

Client-Side Script

Add Client-Side Script Code

Web Services

Use Custom .NET Collections

Create and use .NET custom collection classes to pass containers of data in your Web services projects.

Stateful Web services

This article illustrates a programming technique that let’s you deliver better-performing, stateful Web services by supporting ASP.NET. I'll also show you how to use Simple Object Access Protocol (SOAP) headers to implement additional features, such as custom authentication and authorization, and create more flexible Web services that send and receive additional data that doesn't map to method arguments.

ASP.NET controls

Wizard control to build wizard-based forms

Take advantage of ASP.NET 2.0's new Wizard control to build wizard-based forms with less code.

Repeater, DataList, and DataGrid controls

Repeater, DataList, and DataGrid and what's new for these controls in ASP.NET 2.0.

ASP.NET Server Control

Build an ASP.NET Server Control

Customize Tabular Display

Customize Tabular Display for DataBinding controls like DataGrid.

Multiple Arguments to HyperLink

Pass Multiple Arguments to HyperLink Columns

ASP.NET 2.0 performance

Speed Up Your ASP.NET Pages

Here are seven ways to boost the performance of your Web pages and sites.

Improve ASP.NET Application Performance

Increase performance in your ASP.NET applications by handling events in the browser, rather than at the Web server using HTC.

5 Caching Tips

Here's some real-world advice to help you maximize your benefit from ASP.NET caching.

ADO.NET

Use DataReader or DataSet?

ADO.NET exposes two primary classes for retrieving data. Learn to decide which one to use.

Please note that you need to register on ftp online to read complete articles.

Cyclomatic Complexity

2005-08-24T07:07:00.000-07:00

Cyclomatic Complexity helps to find the complexity of code. Cyclomatic Complexity verification has been added in latest version of FxCop. I found this feature of great help while doing code review with the help of FxCop.

This is good article on Code Review and Complexity by Michael Swanson (Senior Consultant,Microsoft Corporation). This article also explains the advantages of McCabe's Cyclomatic Complexity as:

It is very easy to compute
Unlike other complexity measurements, it can be computed immediately in the development lifecycle (which makes it Agile-friendly)
It provides a good indicator of the ease of code maintenance
It can help focus testing efforts
It makes it easy to find complex code for formal review

This is a good presentation on Taming the Software
Development Process by Michael Swanson (Senior Consultant,Microsoft Corporation). This presentation also explains the cyclomatic complexity and its advantages.

Rob Caron's Blog

2005-08-16T07:38:00.000-07:00

I like and read the articles on "Rob Caron's Blog A Team System Nexus". He has listed a suggested readings for Team Systems which is great.

Rob Caron's Blog A Team System Nexus

Microsoft Windows Vista

2005-08-02T21:34:00.000-07:00

Microsoft has named its new windows as Vista and they just released its Beta1.
Check out this site for windows vista
Windows Vista .

Visual Studio .NET IDE for Linux!

2005-07-28T06:16:00.000-07:00

Check the latest Visual Studio .NET IDE for Linux! on code project or at http://dev.mainsoft.com/Default.aspx?tabid=45.

Using Configuration Files in NUnit

2005-07-17T22:19:00.000-07:00

Using configuration file for NUnit is similar to web.config file in ASP.NET web application and application.config for executables.

What will you do when NUnit requires a .DLL assembly and your code has been written to use a configuration file? The answer is that you will create a configuration file for testing using NUnit J.

NUnit creates an instance of the AppDomain for the .DLL you are testing. One of the other things it does is to manually look for an assembly.dll.config file. Thus, if you need configuration options for your application, copy those settings into a .config file for testing. In our example, such a .config file would be MyDll.dll.config, placed in the same directory as the test DLL loaded by NUnit.

Lets say I have a method bool IsNum(string val) in my MyDLL class (MyDll.dll) which takes a string as parameter and if the string is a number is will return true else false.

What I want is that I create generic test using NUnit and different values passed to my IsNum method to test should be read from the config file. The test should be performed as many times as there are test values in my configuration file. So tomorrow if I want to pass a new value to see if my method is working correctly or not I just need to add a new entry in the config file.

This is my sample MyDll.dll.config file:

Place this config file with your test dll.

Now my Test method will look like:

[Test]
public void ValidateNumberTest()
{
NameValueCollection nvc = (NameValueCollection) ConfigurationSettings.GetConfig("ValidateNumberTest");
MyDll d = new MyDll();
string val = "";
for(int i=0;i< nvc.Count;i++)
{
val = nvc.Get(i);
Assert.AreEqual(true,d.IsNum(val));
}
}

I know this sample is not a great one but I think it gives a fair Idea how we can use a configuration file with NUnit.

Cracking .NET Assemblies

2005-07-12T02:44:00.000-07:00

Today one of my friends send me a link of an article describing how to crack a .NET assembly. I liked this article very much and thought to put that link in my blog :).

http://www.grimes.demon.co.uk/workshops/fusionWSCrackOne.htm

This article describes how to crack and tamper a .NET assembly. It aslo explains the process of strong naming of an assemble and how to crack strong named .NET assemblies.

But the good news is that the approach explained in this article to crack and tamper .NET strong named assemblies does not work in new version of .NET i.e. this has been corrected in new version of .NET.

Large Number of DLLs and circular dependencies

2005-06-27T22:42:00.000-07:00

I think every one should read this thread on gotDotNet message board about too many DLLs.
http://www.gotdotnet.com/Community/MessageBoard/Thread.aspx?id=301653

"Try grouping things by application type/usage. Keep in mind that there is an issue when creating circular references. If DLL A references DLL B, DLL B can't reference DLL A because it would create a circular dependency. This means that you will want to carefully plan which classes go into which DLL's/class libraries. This is an artifact of assembly metadata. Circular references are possible in code using reflection. ".

Visual Studio does not allow adding circular dependencies if you have all your projects in a single solution and add refrence to projects.

While it's true that circular references should be avoided and indicate questionable design, it should be mentioned that this is not always feasible or possible. Real life can get ugly. I don't have much idea when in real life we will have to use circular dependency. If some one can help me understand and let me know in what circumstances we should allow circular dependencies and what precautions should be taken in these cases it would be a great knowledge for me.

Linking Code File to more than one project and GlobalAssemblyInfo.cs in VS.NET 2003

2005-06-16T03:16:00.000-07:00

Today I downloaded and installed Microsft Enterprise Library and while going through the code I found the GlobalAssemblyInfo.cs file. Two things which were new for me were:

1. GlobalassemblyInfo.cs
2. Linking same GlobalassemblyInfo.cs to all projects in the solution.

I found out that there is a "link File" button hidden under the "open" button when adding an existing item to a project which can be used to share a code file between two projects, or a "Solution Item" in multiple projects.

GlobalAssemblyInfo.cs is used to provide the same versioning information to all dlls. You can delete the attributes from AssemblyInfo.cs and stick these in GlobalAssemblyInfo.cs. Then link this GlobalAssemblyInfo.cs to all projects in the solution.