Murali's Arena

Article on software dependencies

2008-08-31T16:12:00.004+10:00

I came accross a very good article on software dependencies and I encourage you to have a look when you have some time for a reading.

The auther talks about problems with tightly coupled architectures, effect of coupling on testing and other design patterns such as dependency inversion and dependency injection. Read the full article here.

Cloud computing

2008-05-07T11:35:00.001+10:00

I don't think that I can find a Software Professional who is not aware of this technical phrase 'Cloud Computing'. It is the current talk of the town.

This article on 'Cloud Computing' describes about the term, how Google and IBM would probably dominate the world in this area and its consequences.

Personal data on Facebook at risk

2008-05-02T10:43:00.001+10:00

A news published on the BBC website has reported with proof, that how the personal information of the Facebook users can be hacked and used for any other purposes.

An application written for Facebook can gather the user's personal data as well as his/her friends', when it is added to the user's profile. That means, you can't stay secured by not adding any applications to your profile; You details ca be stolen when one of your friends adds those malicious application.

Read the full story here.

Schedule delivery of mails in Outlook

2008-05-01T09:46:00.001+10:00

There is a nice feature in Outlook 2003/2007, which makes it possible to delay the delivery of a message. This should be very useful in many occasions but one simple situation is when we want to send wishes to a person on his/her birthday or anniversary. We don't have to worry about whether we are away from the computers on that day, the message will be sent by the server on the scheduled time (this will work only when outlook is connected in exchange server mode).

Read more from here.

Daylight Saving time

2008-03-28T11:45:00.001+11:00

A news story says that the PCs in some states (New South Wales, Victoria, ACT, Tasmania and South Australia) of Australia, will not be able to automatically adjust the daylight saving time this year. Not mentioned in the story, according to one of my colleagues in New Zealand, this will affect them as well.

A software update from Microsoft may solve the problem.

Read the full story

Percentile calculation in Oracle

2008-03-12T12:26:00.001+11:00

A percentile is the value of a variable below which a certain percent of observations fall. That is; the 80th percentile is the value below which 80% of the observations can be found. More informations about percentile and the mathematical calculations can be found on the wiki page.

I had to use percentile function in one of our applications where the only option was to use Oracle. I did some research on the subject and found the solution.

There are 2 analytic functions in oracle which can be used for the purpose finding the percentile.

1. Function: Percent_Rank
This function gives the percentile rank, between 0 and 1, in the set (table rows).
Format:
PERCENT_RANK(<value>) OVER (<partition_clause> <order_by_clause>)

E.g.:
SELECT department_id, last_name, salary, PERCENT_RANK()
OVER (PARTITION BY department_id ORDER BY salary DESC) AS pr
FROM employees
ORDER BY pr, salary;
The results of this query will present the department, employee last name, salary and the percentile rank of the salary within the department the employee belongs to, order by percentile rank and salary.

2. Function: Percentile_Cont
This assumes a continuous distribution; the function will retrieve the value for a given percentile.
Format:
PERCENTILE_CONT(<value>) WITHIN GROUP (ORDER BY <expression> [ASC | DESC]) OVER (<partition_clause>)

E.g.:
SELECT last_name, salary, department_id,
PERCENTILE_CONT(0.5) WITHIN GROUP (ORDER BY salary DESC)
OVER (PARTITION BY department_id) PCT_CONT,
PERCENT_RANK()
OVER (PARTITION BY department_id ORDER BY salary DESC) PCT_RANK
FROM employees
WHERE department_id IN (30, 60);
This query returns the employee last name, salary, department, 50th percentile value of the salaries within the departments, percentile rank of the employee salary for departments 30 and 50.

These analytics functions may take some time to response when queried against large tables.

Long wait is over

2008-02-22T14:58:00.001+11:00

I had been away from posting on my blog for more than 3 months. I was neither busy with office projects nor with personal projects; I made a major move in my life. I and my family migrated to Australia and I was busy with preparing to move from Lanka and settling in the new place.

Now, I am back to my usual life; meaning that I have started blog posting as well.

Encrypting web.config sections

2007-10-26T16:52:00.001+10:00

In ASP.Net web applications, we are used to keep some confidential data in clear text and we do not even care about their importance to the intruders. One of them is the database login credentials, kept in the connectionStrings section of the web configuration (web.config) file.

Recently, I was involved in designing a public secured web application for our customers site. After the implementation was completed, we left the application with our 'IT Security Specialist' to evaluate its secureness. One of his feedbacks was to keep the confidential data encrypted. So, we decided to use the .Net Data Protection API for encrypting the database connection information, i.e. connectionString section in web.config file. I share the details on how to encrypt/decrypt (here I have used the 'machine store' option and it is the good choice when the web site is hosted in a shared environment) the particular section in the file.

Finish the connectionString section configurations in web.config
Open command prompt, change the directory to %WinDir%\Microsoft.NET\Framework\<versionNumber>
e.g. C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727
Execute the following command (AppName: virtual directory name of the
application in IIS e.g. myapplication)
aspnet_regiis -pe "connectionStrings" -app "/AppName"
-prov "DataProtectionConfigurationProvider“
Open web.config file and verify the encrypted section

If it is required to decrypt the section (to change the database settings), this is how to do that.

Open command prompt, change the directory to %WinDir%\Microsoft.NET\Framework\<versionNumber>
e.g. C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727
Execute the following command (AppName: virtual directory name of the
application in IIS e.g. myapplication)
aspnet_regiis -pd "connectionStrings" -app "/AppName"
Open web.config and the section would be in clear text

More information about the Data Protection API can be found here.

Google products you may not know about

2007-10-26T16:19:00.001+10:00

Lifehacker has listed 10 Google products which many people may not be aware of. Even I have not used a few among the list.

Top 10 Google Products You Forgot All About

DevDay 2007

2007-10-19T17:44:00.000+10:00

Microsoft Sri Lanka and the dotnetforum.lk conducted the above event on the 16th Tuesday at the Mount Lavinia Hotel. Yes! this time I was able to attend (I missed a similar one, 3 years back).

There were 2 speakers, 'Chua Wen Ching' from Malaysia, talked mostly about .Net framework 3.5, C# 3.0 and LINQ and 'Venkata Rangan' from India, talked about the 'Windows Presentation Foundation (WPF)' and 'Silverlight'. It was a bit difficult to tune to Ching's English, but the contents of the presentations were good and at last he ran out of time because of too many demos. Venkata had made his session more interesting by showing colorful animations, mainly a matrimony site with pictures of lots of young girls :-).

I expected to receive a Visual Studio .Net 2008 beta installation DVD at the end of the event, but the forum guys said it had not arrived on time to Lanka.

Backlinks to your site

2007-10-15T16:43:00.000+10:00

I just came accross a web site especially useful for web masters. Its Backlink Watch.

We can type the URL into Backlink Watch and get complete detailed information about the quality and quantity of backward links pointing to the website. It shows anchor text, Google Toolbar PageRank, total outbound links on that page and nofollow flag for each of the inbound links available.

I compared the 'backlink watch' results for my site with the results from Google 'web master tools'; This site had provided a more complete and accurate information.

Umbraco tip - Publish event action handler

2007-10-12T14:50:00.000+10:00

I have been working with Umbraco, the open source CMS (content management system) in .Net, for quite some time. Though it is a good system with many features, the documentation available on the web is not sufficient enough to help the developers with their 'how to' questions. So, I think the help should be provided by sharing the knowledge. With that in mind, I like to include useful umbraco tips within my blog, starting from this post.

There can be many situations where one would want to catch the default events and to implement custom action handlers. One of the important events in a CMS is the 'Publish' event and I have provided here the code to implement a custom action handler.

It is used to make the navigation menu (drop down or what ever) on a web site to be dynamic so that it can be automatically updated without the developer intervention. Usually an editor who adds or removes pages from a site would see this feature a really useful one in CMS enabled site. Here the technic is that, when the home page of the site is published, it automatically updates the javascript which is used for the navigation menu.

The steps to follow;

Create a visual studio project to build an application library
Create a class and add the following code
Change the code according to your requirements
Build the solution
Place the built dll file into the umbraco installation's 'bin' folder
Verify the action form the umbraco management site

Code fragment

public class MenuHandler : umbraco.BusinessLogic.Actions.IActionHandler
{

String umbraco.BusinessLogic.Actions.IActionHandler.HandlerName()
{
// return the name of the custom action handler
return "lib.MenuHandler";
}

umbraco.interfaces.IAction[] umbraco.BusinessLogic.Actions.IActionHandler.ReturnActions()
{
// return the actions for which this action handler is used
return new IAction[] { new ActionPublish() };
}

Boolean umbraco.BusinessLogic.Actions.IActionHandler.Execute(
umbraco.cms.businesslogic.web.Document documentObject, umbraco.interfaces.IAction action)
{
// if more than one actions are returned in ReturnActions() method,
// the action parameter can be used to decide the current action.

// check whether it is the home page which has been published
if (documentObject.ContentType.Alias.Equals("HomePage"))
{
// Code to rebuild the navigation menu
}
}

}

Perfect domain for me

2007-09-27T17:44:00.000+10:00

I have been trying to get the perfect domain (www.balamurali.com) for my online presence, for some time, but I didn't succeed until the previous registration expired last month. After years of patience, I grabbed my dream domain through the domain auction agent snapnames.

From now onwards Balamurali.com will be my permanent place, globally on the web, and I'm trying to find some free time to renovate my personal web.

Engineering vs Software Engineering

2007-08-22T15:27:00.000+10:00

In the last issue of 'Engineering and Technology' magazine by the IET, I read a small article (I forgot the name of the author but I remember the topic). It was about the usage of the job title 'Engineer' within the software industry. The author had said that an Engineer should be a person who is involved in hardware design and manufacturing activities. In all the other industries such as 'Civil', 'Electronics', 'Mechanics', 'Aeronaughtics' etc. the tasks of an Engineer is related to designing hardware components. In contrast, the software industry has been mis-using the job title 'Engineer' for people who design software, which difers a lot from usual engineering processes. Hence, they should be called 'Software Designers' instead, he had further added.

I have been hearing these kinds of arguements time to time from various people I meet. The reasons I think for all these mis-understandings are;

1. Software industry has not matured enough or it has not aged well to define its standards.
2. Software Engineering is a totally different aspect of Engineering where people are new to the intangible properties of the product and its capabilities.

Because of its immatured nature, the people in this industry have started using many different job titles without standardizing/defining them in a proper way. This has lead to many problems and mis-understanding. However, I believe that the 'software engineering' would soon come under the 'umbrella of engineering' as the community become more aware about the issues nowadays.

One puzzle

2007-08-06T14:57:00.000+10:00

Most of the time, I enjoy listening to radio channels rather than playing a music CD on my car stereo. Comperes can make the channels more interesting by having lots of fun items within the programs. One stuff they often do is 'riddling'. They throw away some quiz questions and let the audience answer them through the phone.

Today, on my way to the office I heard this quiz, being asked again and again by the Compere but not answered for hours of time.

Greater than God, more evil than the devil, the poor have it, the rich need it, and if you eat it, you will die. What's that?

He was also providing some statistics about the riddle; He said 80% of kinder-garden students answered while only 17% of Standford university seniors. I didn't get the answer during my journey so I searched the net when I reached the office and found out that it is a famous riddle.

The answer is 'Nothing'.

Now I can read the puzzle with the answer in place.

Nothing is greater than God; nothing is more evil than the devil; the poor have nothing; the rich need nothing; and if you eat nothing, you will die.

Multiple web sites in IIS 5.1

2007-08-01T20:37:00.000+10:00

Last few weeks I had been working with one web based CMS (Content Management System) software called Umbraco. The system has a limitation which does not allow it to be hosted inside a virtual directory within IIS. It has to be installed in the web server root in order for it to work properly.

I wanted to install and try the software at any cost. However, I didn't want to mess up my existing web server as I have already configured many virtual directories in it. I could not create a new web site instance through IIS also because, its not possible with Windows XP Professional and IIS 5.1. I had to find a solution for the problem because I couldn't just find a machine to install the new software only. So, as usual I googled the net and I could find some cool tools available to do the trick. Here I share the tool which I still use in my machine.

IIsAdmin.NET: Create Multiple Web Sites Under Windows XP

The only limitation with the tool is that only one web site can be active at one time. Since I use my machine for development purposes I feel it is tolerable.

Team Trip - Hotel Blue Water

2007-07-31T19:59:00.000+10:00

Our project code-named 'JERI' was successfully completed by mid of June and as usual we were allocated the fund by our Development Manager to go for a trip (team outing). It's just after around one month of our annual trip, which we didn't appreciate much. So, this time we wanted to visit a near-by beach hotel so that we could reduce the cost and time for travelling and spend more for hotel stay. We didn't have any second comment in choosing the hotel The Blue Water in Wadduwa as the destination.

July 28-29, was very much entertaining and relaxing weekend at a wonderful hotel surrounded by fantastic coastal atmosphere. We admired the way the water is circulated everywhere including the huge swimming pool, keeping the place really cool.

As the event was with lots of fun stories, I think my photo album would say it all. Here is the link.

Trip to Hotel - The Blue Water

LinkedIn or Facebook?

2007-07-27T15:51:00.000+10:00

People often talk about Facebook and LinkedIn, 2 popular social networking services. I have been using LinkedIn for sometime and it's not new for me. I wanted to know how the Facebook works and its pros (or cons) over the other service.

This article seems to address the issue by comparing the 2 services. Today I have planned to explore the features of Facebook little more so I can verify the author's comments.

Entrepreneurs Need Both Facebook and LinkedIn

My LinkedIn profile

Open source Content Management Systems

2007-07-18T18:16:00.000+10:00

There was a need for me to investigate about several open source Content Management Systems (CMS) for a personal project. It was a big list where I had to choose the better one which suit my requirements. Three systems were in my short-list.

I had already worked with a commercial Enterprise CMS, called Tridion in my company. So, I didn't have any problems when evaluating the functionalities in each system in my short list.

Here I talk about the system which I have chosen to be the best within the short listed candidates.

Umbraco (http://www.umbraco.org/)

This is an ASP.NET based CMS, uses Microsoft Sql Server as the backend. Currently the latest stable version is 3.0.1.

It took more than half-a-day for me to install because there were lots of problems I had to solve during the installation. I found out that, when it is installed in IIS web server, it should be the root application. It cannot be installed in a virtual directory. I used the Sql Server Express 2005 which I installed as an instance (not the default option). It raised a lots of error messages when I tried to access the application saying that it could not get the database connection (even after I configured it properly). Then I had to re-install the database with the default option.

I write this small review with my usage of few hours of the software, so I might have missed a good feature altogether. So, please bear with me. I'll update my blog with my experience later. This is the only CMS which is similar atleast in few features of the standard Tridion software. This has the flexibility of making the building blocks of the web site from scratch. When it is installed fresh, there is no predefined settings, even for the member groups. It is possible to create a simple web site without using the .Net programming knowledge at all. But it is necessary to have enough programming skills to build a sophisticated web site. Developers have the option of utilising the .Net web/user controls or the XSLT style sheet to define the layout and contents.

Other options in my list were Mambo and Cuyahoga. I didn't go deep into the features of Mambo as it has used PHP for its front end which is not suitable for my purpose. The laster has used ASP.Net for front-end and Sql server, MySql or PostgreSql for the back-end. Though this offers flexibility in database, the features were not useful. I can say it has limited range of usage.

Today is 13th, Friday

2007-07-13T16:10:00.000+10:00

Today is the second Friday the 13th in this year (first one was in April), believed to be the most unlucky day by the Englishmen. The fear of 13th Friday has also been given a name, Paraskevidekatriaphobia.

When I searched the Net to get good articles about of this culture, I found a lot of resources. Among them, I feel the below links have got better information.

iPhone review - good one

2007-07-03T18:19:00.000+10:00

Still, I haven't got a chance to try the currently-hot device, Apple iPhone. It has not been yet marketed in our country. I normally use the published reviews to knowledge myself about the new arrivals. Good reviews always help to get the feeling of a hands-on usage of the devices.

Here is a very descriptive and focused review about the recently released iPhone.
iPhone review

Trip to Dickwella

2007-06-25T19:48:00.000+10:00

Dickwella, a place in the south coast of Sri Lanka, had been chosen to be the spot for the company annual trip (for our group). We enjoyed the pleasure trip on 23rd and 24th June at the Dickwella resort. We travelled on Saturday morning in 3 buses and returned on Saunday night.

It was a fun-filled weekend with more relaxation, food, dinner dance, sports and fun events. My wife and kid accompanied me this time and it had been our first long trip with her.

I have shared the photoes in my album.

Trip to Dickwella

Web Browsers - timeline

2007-06-25T15:56:00.000+10:00

The timeline of web browsers shown here seems to be very useful. I can think about the following ways, the information can be utilized.

Details of all the existing / non-existing web browsers and their version release periods
The ways in which different web browsers have evolved and their ancestors
Maturity levels of the browsers
etc. (there may be more)

I couldn't find the famous text based 'lynx' browser (found in Linux OS) in the timeline. May be it was not considered as a web browser?

Web 2.0 - design guidelines

2007-06-22T15:11:00.000+10:00

I was googling to find some resources about web 2.0 design trends. I say web 2.0 design trend because the web sites' designs have changed drastically since the introduction of web 2.0 services. I found this as a good article on the topic.

web 2.0 how-to design style guide

It gives good explanations on the changes to the web design with examples and some links to more information.

Opera Mini - mobile browser

2007-06-14T13:54:00.000+10:00

While I was in Sweden, I met Ms. Malin Rundberg, Project Manager of Opera Mini software, at Graziela's (our Development Manager) birthday party. We had a good chat about various things for some time. One of the topics was about the Opera Mini, the free mobile browser.

I use Nokia 6230 and I had been using its default browser to access the internet over GPRS. At the party Malin recommended me to use the Opera Mini, not just because she is the Project Manager of it, but it has got some nice features. When she was telling the features of the software, I was thinking like, 'how did I miss this nice piece of software?'. I decided to try this when I'm back home.

I downloaded the software and I have been using it for a while. It's amazing! If I say the truth, now I don't like to open my phone's default browser at all. I recommend this software for everybody around and I should thank Malin for introducing me to this application.
This is how you install the product (phone should support java applications):

Open the default mobile browser and connect to the internet
Access the site www.operamini.com
Download the software by clicking the appropriate link
Allow the phone to install the java application
Exit your phone browser, now the application has been installed.

Opening the browser is as easy as running a java application in the phone. Just select the 'Opera Mini' from the phone's applications collection and let it to connect to the internet (you will be prompted to allow network access). Now you can play with it.