ASP.NET 2.0 Beginners Troubleshooting Guide

Problem: I'm using ASP.NET 2.0's membership provider for forms authentication. It is working fine in VS environment with the integrated web server. But when I move it to IIS, login control fails to authenticate the same user.

Resolution : In IIS the account(ASPNET or NETWORK SERVICE) access the app_data folder. Therefore the app_data folder must have write/modify permission for this account

I will try to add some troubleshooting tips into this article time to time.

Do you believe in Unit Testing

Most of the developers don't believe in unit testing. As for my experience I don't really blame for developers. Why they are not attempting is b'cos product/project release time pressures. Many software houses have not embraced unit testing into their process therefore the time component of unit testing is not included in the estimation. But that's only an one aspect of it the other side is lack of knowledge and training on proper unit testing tools and practices. If you are planing to implement unit testing process for your team have a look the flowing tools. They are very useful to implement the unit testing process properly. One of the good book in this topic is Art Of Unit Testing by Roy Osherove".

Here is how one of Microsoft MVP's described this book

“Beautifully craft ed, detailed unit testing masterpiece.
Bravo, Bravo, Bravo!”
—Mohammad Azam, Microsoft MVP, HighOnCoding

Some of the supplementary tools are :

- NDbUnit, DbUnit
- Rhino Mocks, NMock
- Fit, WinFITRunnerLite
- TypeMock
- NUnitAsp

Enjoy and Rethink about unit testing.....

.NET Tools Portal

Sometimes it's difficult to find the correct tool at the correct time. I found this portal for .NET tools a common place to some valuable tools. It has categorized the tools nicely and easy to find. Here is the site

Maintainable Regular Expressions

We all know regular expression is a very powerful tool. But one of the difficulties we face is reading regex statements written by others. Sometimes it's almost impossible. So it's always better to document your regular expressions and make them more readable for others and make your piece of code more maintainable. Here what you can do

Regex regex = new Regex(@"
^ # anchor at the start
(?=.*\d) # must contain at least one numeric character
(?=.*[a-z]) # must contain one lowercase character
(?=.*[A-Z]) # must contain one uppercase character
.{8,10} # From 8 to 10 characters in length
\s # allows a space
$ # anchor at the end",
RegexOptions.IgnorePatternWhitespace);

You can comment your expressions using # but make sure you use the RegexOption IgnorePatternWhitespace.

How to Study with your Spouse, Children and a Full Time Job

You may be wondering this is impossible. 50% of my colleagues don't believe in this and they destroy their careers after they got married and have started on their kids. Read this article this is a good one to keep you energize and to move up with your career. Though you have not done your degree or professional certifications you will be up-to-date in your industry by following this and count on me you will be in a good position in your work place :)))

How to Study with Full Time Job

CSS Friendly Adaptor Controls

Our web designers are always complain about the code generated from ASP.NET controls. For an example code generated from Menu controls are using table tags. But modern web designers love CSS based menus b'cos of two reasons. They looks elegant and the page size is very small compared to table base menus. So here is what you are looking for...... CSS Friendly Adaptor Controls, brilliant piece of work. You can make your existing site produce CSS friendly code and style your controls using CSS without even touching your existing aspx pages. It's definitely a wow isn't it :) Actually it is.... Compare the following rendered html using adaptor control with your own table base menu rendering results you will feel the difference.

<div class="SimpleEntertainmentMenu" id="Menu1">
 <div class="AspNet-Menu-Horizontal">
   <ul class="AspNet-Menu">
    <li class="AspNet-Menu-WithChildren">
     <a href="javascript:__doPostBack('Menu1','bMusic')" class="AspNet-Menu-Link">
      Music</a>

     <ul>
      <li class="AspNet-Menu-Leaf">
       <a href="javascript:__doPostBack('Menu1','bMusic\\Clasical')" class="AspNet-Menu-Link">
        Clasical</a>
      </li>
     </ul>
    </li>
    <li class="AspNet-Menu-WithChildren">

     <a href="javascript:__doPostBack('Menu1','bMovies')" class="AspNet-Menu-Link">
      Movies</a>
     <ul>
      <li class="AspNet-Menu-Leaf">
       <a href="javascript:__doPostBack('Menu1','bMovies\\Action')" class="AspNet-Menu-Link">
        Action</a>
      </li>
     </ul>

    </li>
   </ul>

 </div>
</div>

In the App_Browsers folder create the CSSFriendlyAdapters.browser and configure all the adaptor controls to be used with different ASP.NET controls.
In this file you can configure in which browsers Adaptor controls should be enabled or disables. Please refer CSS Friendly Adaptors for more details

MS SQLEXPRESS Issue

If somebody is getting the following error when trying to create new sqlexpress data bases from Visual Studio please follow the instructions bellow to sort out the problem. I've been struggling for couple of hours to figure out the problem

Error : "Failed to generate a user instance of SQL Server due to a failure in starting the process for the user instance"

Resolution : Delete C:\Documents and Settings\USERNAME\Local Settings\Application Data\Microsoft\Microsoft SQL Server Data\SQLEXPRESS.

This is definitely authentication problem. When you uninstall and reinstall sqlexpress it can happen.

Automate your Build and Packaging Process

Check this out great toolset for automate your build and packaging process

Wix ToolSet
Tips and Tricks
Learn MSBUILD

Beauty Of .NET (Extender Controls)

Have you ever wanted to extend functionality of .NET controls ? if so first thing you will do is subclasing the control and implement your functionality. Hmm there is a much more elegant way of doing this by using Extender Controls.

Extender controls allows you to extend functionality of exiting controls in a form without subclasing. You have to only drag the extender control to the form and there you go ..... all the controls in the form are equipped with the new functionality.

The basics are very simple, and you have to build the rest according to your needs. End of this article I have presented some interesting things that can be done using this technique. Extender control is a component so you have inherit your class from a component and implement the IExtenderProvider interface.

[ProvideProperty("HelloWorld",typeof(System.ComponentModel.Component))]
public class HelloWorldComponent : Component,IExtenderProvider

IExtenderProvider interface is very simple. You have to only implement the CanExtend method.

public bool CanExtend(object extendee)
{
if (extendee is Control && !(extendee is HelloWorldComponent))
{
return true;
}
else
{
return false;
}
}

The above will extend all the controls in a form (win or web) with properties extended from extender control. You can introduce one to many properties to controls in a form using one extender control. For introduce a property you have implement two methods Set(Component,String) and Get(Component). ProvideProperty attribute gives names of the properties. Pls refer Extender Controls Tutorial for more details on creating and using extender controls.


Interesting things you can do with Extender Controls

1) UI Security Implementations
2) Two Way Data Binding in ASP.NET for simple controls like text boxes and radio buttons

Have fun.........

Robust Coding with CBO's and Hydrator

I thought of giving some of my thoughts on DAL and BL designing. Some buzz words today among designers are DTO's and Business Objects (BO's). DTO Vs BO discussion is somewhat controversy and I'm not going to touch that here :). DTO's are smiler to CBO's (Custom Business Objects) that I'm talking in this article.

First I'll refer to a Framework that use CBO's and hydrator design pattern. DotnetNuke is a open source Content Management and Portal development framework (http://www.dotnetnuke.com/). It has a large community and fairly stable product. We have used this for couple of commercial products and customers are happy so do we. The complete data layer of this solution is built on CBO's and a Hydrator. This greatly reduces the size of the code and it's complexity.

If you are using CBO's in your code just think how are you going to populate those objects using a DaraReader. If you are going to hand code all the filling mechanisms definitely it's going to be a nightmare. Just think the the maintenance effort, if you change something in the data model you have to go and change the filling codes as well. You can greatly reduce this complexity by using a hydrator or a helper class with CBO's to automatically fill your CBO's based on reflection.

Few hints on how to write a flexible helper class (Hydrator)

• Use .NET 2.0 Generics to define the FillCollection method

public static C FillCollection(Type objType, IDataReader dr)
where T : class, new()
where C : ICollection, new()

By using generics you can generalize the method to use custom return collections as well as to define concrete objects to be filled at compile time. What I love about this is you can specify generic constraint using where clause.

C# supports five different constraints:

1. Interface constraint - The type argument must implement the specified interface.
2. Inheritance constraint - The type argument must derive from the specified base class.
3. Class constraint - The type argument must be a reference type.
4. Struct constraint - The type argument must be a value type.
5. New constraint - The type argument must expose a public, parameterless (default) constructor.

In the above "where T : class, new()" means the object should be a reference type and it should have a parameterless constructor

• Use Custom Attributes to map object properties to DB columns and to define custom values to null properties. So you don't have to use the same DB column names in your object properties and you can override default null values.

Download Code

Google Apps

My friend Hasith one day showed me this interesting concept of google docs. Though I was not that interested on it, Today i thought of just looking at it. I came across this online Google Application concept it's not just Google docs, it has different application packages for home users, small business users, enterprise users etc. It's interesting concept ah! Everything is 100% free :) only requirement is you have to have a domain name to get registered into Google apps. Before I was using MS word to write my blog posts today I'm using Google Docs Wow. The great benefit I'm getting is I can write my documents if I can get hold of a computer and Internet connection. I don't have to wait till I come home or to the office. This is a hassle free powerful communication & collaborative platform for all of us enjoy!

Connection Strings

Guys who want's to refer connection strings here is the site http://www.connectionstrings.com/

.NET Documentation Compilers

When Microsoft introduces XML documentation I was wondering why Microsoft didn’t introduce a compiler to compile this XML documentation into nice looking API’s. Hmm I don’t have an answer for it but some open source guys came up with a good tool (NDOC) for this need. Guys who have the experience in NDOC know what I’m talking about. If you don’t know about NDOC have a look at http://sourceforge.net/projects/ndoc/

Now the good news is Microsoft have open up there internal MSDN style XML documentation tool to the community. All who are interested in code / API documentation look at SandCastle. http://blogs.msdn.com/sandcastle/ is a good place to hang around. Download it from http://www.microsoft.com/downloads

SandCastle is purely command prompt base set of tools and compilers. If you like to get a technical overview of the tool have a look at this blog

https://blogs.msdn.com/sandcastle/archive/2006/07/28/681209.aspx

Some guys have written a NDOC style application in top of SandCastle tools and can be found at http://www.codeplex.com/SHFB

Enjoy !

Change Your Destiny....

Last 3 days I attended the Microsoft Tech.ED 2006 held at Waters Edge Sri Lanka. It was a good experience but bit pissed off b'cos the expected contents are not delivard in this 3 days of sessions. I'm not expected marketing presentations in a TechED forum. Do you? Some of the speakers new what they are talking about (technically fluent) but that is less than 40% of them and the rest are Marketing guys.

Actually I loved the concept of "People Ready" software which I believe futuristic concept. It shows the maturity of the IT industry. Big thanks go to Microsoft for addressing this and I hope Microsoft will think backward compatibility issues and not to discontinue their tools and platforms as they wish b'cos many is going to suffer from it.

ADO.NET Data Reader Vs DataSet

ADO.NET Data Reader Vs DataSet

For a long time I was thinking of maintaining my own blog, but unfortunately I couldn’t find time for it since I’m always busy with my office work.

Though I’m enjoying my daily life style very much, I always feel I’m not sharing my thoughts and knowledge with others. So here is my first writing in the area of ADO.NET.

Let’s start

When I first heard the name ADO.NET I thought this is the next version of classic ADO. But I was wrong it’s totally new set of components that are optimized to the internet world.

ADO.NET provides two options to retrieve data from an underlying data source. Those are: DataSet and

DataReader

The above are exposed through different providers in ADO.NET. Data providers in .NET framework are used to connect to a database execute commands and retrieve data. This resides as a thin layer between the code base and the data source which optimizes the connectivity.

Lets start with DataReader

There are number of Data Providers in ADO.NET which has its own implementations of DataReader. Commonly they all have implemented the IDataReader interface. If you are sending out the DataReader from a method you can send it out as IDataReader which wraps the actual implementation which solves the problem of many actual implementations when passing the DataReader around different layers of your design.

DataReader is a one way forward only, read only method to read data from a result set. Once you get data into a DataReader it’s very important to remember that the pointer is just before the first record in the result set. You have to call .Read() which moves the pointer to the next location in the result set and returns “true” if it is a valid row.

Common way of reading data from a DaraReader is as follows:

SqlDataReader reader = command.ExecuteReader();

If(reader.HasRows)
{

while(reader.Read())

{
…..
}
}

DataSets

DataSets are database independent in memory data store which can be used to access one or many tables. It can contain one or many DataTables and these tables can contain rows and columns of data.

Data within DataSets can be updated by the user and can persist to the underplaying data store through DataAdapters. DataAdapters are database specific implementations in DataProiders.

Which to be used?

If you need one way read only access to data that we often need in ASP.NET DataReader makes sense. ASP.NET is a stateless technology and you will not hold any data or database connections between requests. ASP.NET allows holding data using session state but it’s not the ideal model to hold custom DataSets between requests and will not make your solution scalable.

The bad side of DataReader is it keeps the database connection open till you finish entire processing of your data. So keep in mind if you have any long processing requirements DataSets may be ideal.

For windows and Smart client applications DataSets are ideal since they maintain their state whole through its life time. The dark side of using DataSet is it holds the entire data store in memory. This may cause high memory requirements if you are loading thousands and millions of data into these DataSets. Data readers are ideal in such cases.

Some Key Points

If you are passing a DataReader around your logical layers there is an inherent problem of closing the Database connection. This is one of the mistakes developers do in their developments which causes application performance and scalable issues. This issue can be solved by using the CommandBehavior.CloseConnection parameter with the ExecureReader which automatically close the database connection when closing the DataReader.

command.ExecuteReader(CommandBehavior.CloseConnection)

DataSets can be easily converted into XML and vise versa, this can be very useful if you want to serialize data across the wire (.ReadXML, .WriteXML methods can be used).

DataSets are accepted by ASP.NET web services and can return DataSets as well. You must be thinking this is strange, though you think it’s limits usability of you web service, it might be a good reason to use those features if you know all your web service consumers are .NET.