Pragash

2011-09-29T02:29:00.001-07:00

private static void generateHashMapFromString(String line) {
Hashtable hsh = new Hashtable();

int s_index = line.indexOf("{");
int e_index = line.indexOf("}");

//Extract the message line from the sent message
String msg_line = line.substring(s_index + 1, e_index);

//Split the msg_line into an array using "," delimeter
String[] arr_lines = msg_line.split(",");

String l = "";
for(int i = 0; i < arr_lines.length; i++) {
l = arr_lines[i];

String[] k = l.split(":");

hsh.put(k[0], k[1]);
}

System.out.println(hsh);
}

பெர்முடதியன் இன் Python

2011-09-23T10:02:00.000-07:00

Last time I wrote a post on how to write permutation in Ruby. Since, I have started learning some Python I thought to do the same thing with Python as well. Please find the code below,


#! /usr/bin/python2.7

def permutate(a):
  n = []

  for i in a:
    c = a[:]
    c.remove(i)

    if len(a) == 2:
      n.append("%s%s"%(a[0], a[1]))
      n.append("%s%s"%(a[1], a[0]))

      return n
    else:
      d = permutate(c)
      for k in d:
        n.append("%s%s"%(i, k))
    
  return n

if __name__ == '__main__':
  print permutate([1,2,3,4])

Some funny coding.....

2011-09-09T10:38:00.000-07:00

I thought of writing some code that is really fun and interesting along with my team mates. So, I'll be able to publish some code on Ruby over the next few weeks. The plan is to implement some simple algorithm for doing some very basic mathematics. As a beginning I've written two codes to generate Fibonacci numbers and Permutation.

Permutation


def calculate_combination(arr_params)
  arr_combination = []
  arr_params.each do |e|
     #delete the current item from the array and assign it to a temp array. 
     #This will not have an effect over the original array
    tmp_params = generate_temp_array(arr_params, e)

    if arr_params.length == 2
      arr_combination[0] = "#{arr_params[0]}#{arr_params[1]}"
      arr_combination[1] = "#{arr_params[1]}#{arr_params[0]}"

      return arr_combination
    else
      arr_new_combination = calculate_combination(tmp_params)
      arr_new_combination.collect{ |x| arr_combination << "#{e}#{x}" }
    end
  end

  return arr_combination
end

def generate_temp_array(a, i)
  arr = []

  a.each do |v|
    arr << v unless v == i
  end

  arr
end

result = calculate_combination(["a", "b", "c"])

Fibonacci Numbers


def generate_fibonacci_number(limit)
  n = 0
  f = []
  valid = true

  f << 0
  begin
    n = f[f.length - 1] + f[f.length - 2] if n >= 1
    n = 1 if n == 0

    valid = n < limit
    f << n if valid
  end while valid

  f
end

f = generate_fibonacci_number(100)

Mantis to Redmine....

2011-08-05T22:09:00.000-07:00

It's been a long time since I moved away from Mantis for bug tracking and started using Redmine which is more of a project management tool. Redmine allows you to maintain a wiki, issue tracker, repository viewer and road map for each project. This way of isolating projects from one another makes Redmine very clean. And in fact it is easier to work with it as it is just one single project that you have to worry about when using the system. So, it's easier to search files, issues, etc..
Well if you are planning to migrate from Mantis to any other bug tracking tool I'd recommend to give it a try with Redmine, as it is open source, user friendly and feature rich.

In order to move your old data from mantis to Redmine just follow the steps below,

1. Set up Ruby on Rails on your PC/Server
2. Download the latest redmine version
i. svn co http://redmine.rubyforge.org/svn/branches/1.2-stable or
ii. http://www.redmine.org/projects/redmine/wiki/Download
3. Navigate to the Redmine root folder
4. Install the required gems "rake gems:install"
5. Set the Redmine database configurations in "config/database.yml" file
6. Run the following task "rake redmine:load_default_data"
7. Then, run "rake redmine:migrate_from_mantis". This will ask a few questions about the mantis database please check atachment. Once you've given all the required information press enter.

There you go, you've got a redmine system loaded with your old data from mantis up and running.

Easy script to set up rails

2011-07-06T10:06:00.000-07:00

I've created a .sh file which will install and set up Ruby, Rails, Mysql in Ubuntu. If any of you want to set up rails then this would be an easy way to get it done without having to spend time browsing the web.

How to use the file?
1. Download the file from here
2. Give 777 permission to the file.
e.g. chmod 777 [filename]
3. Execute the file through the terminal or by double clicking the file.

You should be able to see the progress of Ruby, Rails, Mysql installation as if you are running it manually.

Ruby on Rails training

2011-05-04T06:51:00.000-07:00

I have been working in ROR(Ruby On Rails) over the last 18 months since November 2009. I feel this is one of the best languages which is there in the web development market at present. It can well and truly be competitive with PHP and probably go beyond the limitations of PHP. But, unfortunately it's not widely used in Srilanka. I feel there is a lot of opportunities for ROR developers in countries like USA, UK and rest of the europe. This means that sooner or later it is going to come over here as well because srilanka has a prominant place in off shore development. I along with few of my colleagues have planned to train people who are willing to learn ROR.

The training programme will be really beneficial for developers who are planning to learn and unveil the story behind the ROR and at the same time for students(beginners). If you need to know more about the training drop me an email to pragashonlink@gmail.com.

Gravatar gem

2011-05-04T06:26:00.000-07:00

Today I managed to release my first gem which I created thanks to Bundler. Bundler is a useful gem and one of the things that bundler make easy for you is to create your own gem. Once you run the "bundle gem [gem_name]" it'll create all the required files with which you can get started.

So, this gem which I created will help one to display the image uploaded in gravatar.com on there application by passing the email address. The following shows you the steps that one need to go through in order to get there picture up on there application from gravatar http://en.gravatar.com/site/implement/images/. This gem does all the hard work for you, you just need to pass it an hash and there you go the image will appear in the view of you rails application. I'll write a descriptive doc on how to use this in my next post. This is just to announce that there is a easier way to use gravatar images in your rails application.

Gem installation command

sudo gem install my_gravatar

Learning to draw

2010-12-05T05:48:00.000-08:00

Late last night since I didn't find anything interesting to do so, I thought of learning to draw. I have to admit the fact that my drawing skills are 0. I can't even imagine myself holding a piece of pencil between my fingers trying to draw something(not even a mango that looks somewhat like a mango). So, as usual I started googling to find a website that teaches me how to do this. Thanks to Google I found a quiet a few sites and this site impressed me a lot.

The good thing about this site is that it explains where things went wrong for individuals like me who have given up drawing after 5th 6th class. Also, I now realize that drawing is the first step towards education, every child starts drawing around age 3. Due to some reason we loose the interest or the motivation to keep drawing. After about 15 years I now feel like holding a pencil and drawing(still haven't improved though :) ). Anybody who is feeling the same way I do just check out this site and enjoy.

http://www.learn-to-draw.com/

Continuous integration

2010-03-12T03:13:00.000-08:00

The term team work is inevitably associated with software development. This means most of the time more than 1 person will be working concurrently in a project and will be working in different tasks to arrive at a common goal. Since, there are more than 1 person it is very likely that the code one writes gets overridden or get improperly updated.

Just look at the following scenario,

Developer 1 - Creates a new class named "Employee" and names the class file as "PermanentEmployee.cs"

Developer 2 - Creates another class named "Employee" and name the class file as "Employee.cs"

Both developers will have their unit tests pass locally which means for them they've done a good job in finishing their task. But, when their code is integrated and compiled in order to release a version to the server the compiler will then throw an error. This may sound simple right now but, this is just a sample scenario where things could go wrong at the last moment. According to me integration of code is one of the most difficult part in software development because this is where things may go wrong in a way we never imagined/planned.

So, what could done to avoid last minute headache as this, this is where continuous integration comes into act. What is this thing called continuous integration?? and what sort of a solution can this provide??.

Actually as the name implies continuous integration means a way to integrate all your code continuously. When we have a lot of(more than 1 :)) developers working in a project we can have continuous integration tools(cruise control) setup in a server. These tools will keep an eye on the Source repository(SVN/CVS) and when they find a new version getting created it'll automatically download the latest code from the repository and will run a it in the server along with the tests which are available. During the integration tests if it comes across any error in tests it'll send notification to the developers and q&a who are involved in that project. We can also make manual builds to check if we have a stable version in the repository.

1. Help maintain versions in the repository as stable as possible.
2. Help figure out issues at an early stage before they surface.

So, if all the developers commit the code to the server at the end of the day and when they comeback office the next day they will have notifications about what went wrong with the build so, that they can fix the issue and do another build in the server and make sure it passes. This assures that all the other developers get a stable version to carry on from where they left off without building up on error prone code base.

I recently came across this great tool called CruiseControl which is one of the best tools available for continuous integration. Also, go through the following article

ASP.NET website Continuous Integration+Deployment using CruiseControl.NET, Subversion, MSBuild and Robocopy to get started.

Enjoy.......

Scrum....

2010-03-10T21:57:00.000-08:00

It's been long time since, I last blogged. I took a lot of time out of blogging since I didn't have anything much to blog about :). Today, while I was browsing the Internet I came across this website which has almost all the important things to note about, if you're planning to introduce agile development methodologies at work.

This article defines the building blocks of scrum which is a agile development framework. As a person who has personally worked in Scrum team I believe it is one of the best agile development frameworks that is there which helps keep things Simple and stupid(like a KISS). If you're interested just have a read.

What about some PDF reports........

2009-06-03T09:31:00.000-07:00

Well it's been quiet a long time since, I last posted on my blog. I have done a few things in the past which can be posted in my blog but, I find it dificult to gather these information in a bloggable way. So, How am I writing this post? well, I have a friend who always used to push me to write a post atleast, once a week. I should really thank him for pushing me all the time.

This post will be based on ITextsharp which is an assembly available as a freeware for creating PDF reports.

As enterprise developers we develop systems to help(enable) organizations make key business descisions on it's business domain. System reports play a major part in describing the current state of the business. If the system,budget are huge and the system is considered to be critical then an organization would go for a BI project. If the above said is not the case then they would just hang on with HTML reports. It is not a bad idea to display reports as HTML inorder to stay within budget but, this comes up with certains limitations which can be eliminated by using PDF reports.

There is a well documented and easy to use API available as a .net assembly in http://itextsharp.sourceforge.net/ and could be downloaded for free. There are a lot of things you can do by using this dll. Some of the important points are given below,

HTML to PDF
Support for working with XML,RTF,etc
PDF reports.

The main API has the following namespaces,

iTextSharp.text.xml
iTextSharp.text.rtf
iTextSharp.text.pdf
iTextSharp.text.markup
iTextSharp.text.html

The highlight of all these will be the iTextSharp.text.pdf. We can find almost all kinds of classes and methods which are used to create pdf files. It has two classes to create pdf tables one is Pdftable and the ohter is the PdfPtable. Both, have there own good and bad but, one can use either of these classes and build good looking, portable and feature rich reports. In addition to merely creating files you can also do the following,

Merge PDF files.
Append information in one PDF to another.
Create reports based on a template, etc.

More facts can be gathered in http://itextdocs.lowagie.com/tutorial/. I have attached a couple of reports I created using Itextsharp for you to check out.

I hope this gives you a good impression about this API and the power of it. I suggest one can make some really cool reports using this API with a bit of creativity.

Enjoy.....

Ummmm.... What is better

2009-04-08T10:23:00.000-07:00

As we all know that there was a namespace as System.Web.Mail came in with the release of .net framework1.1 and it was considered as the best technique to send emails in .net until a new namespace was introduced as System.Net.Mail in .net Framework 2.0. This drew the attention of all developers and many told that this is the best technique over System.Web.Mail and this arguement is still valid. I just got a thought while thinking last week and I thought of writing a post on my blog on what makes System.Net.Mail better than System.Web.Mail. I have read a few articles on this and have summarized the information as shown below.

All of us who work in web technologies would have had to send emails in our applications.Before, the introduction of ASP.NET one had to use the CDONTS,CDOSYS APIs developed by microsoft. These APIs gave a set of methods and properties to send emails but, these dlls were tightly coupled with the OS.

With the introduction of ASP.NET which has revolutionised the web developers started moving away from these APIs towards System.Web.Mail. But, unfortunately the System.Web.Mail wasn't a .net native implementation of the SMTP protocol. Instead, it was kind of a wrapper for the CDO,CDONTS dlls. Thus, it wasn't independant from the COM libraries. This made the System.We.Mail more rigid and had to suffer all the issues related to CDO and CDONTS.
Actually, when the Smtp class sends an email it will check the OS version if it is less than 4 then it creates an object of the CDONTS.NewMail else it creates an object of CDO.NewMessage class.
Below is a list of issues related to CDO,CDONTS.

CDONTS has been deprecated in IIS5 and is completely removed from Windows Server 2003, and even Windows XP. Yes, it is possible to install on
Windows Server 2003 but with the performance improvements and other enhancements, there should be no need to do so.
Carries a lot of overhead.
Using the CDO and CDONTS the System.Web.Mail had to be dependent on the COM libraries.

To overcome these issues the ASP.NET 2.0 came up with a new namespace with a new set of classes written from the ground up without any interop. Thus, it is not dependant upon other COM libraries. System.Net.Mail introduces brand new classes for creating and sending email. Although some functionality has been removed, the new System.Net.Mail namespace is much more versatile than the older CDO dependant System.Web.Mail.

The configuration settings to send emails using System.Net.Mail can be directly put in the web.config file which is another cool feature, so that when the Smtpclient.Send() method is called the settings in the web.config is picked up from the configuration file.This can be done through the code as well. Below are the settings which should be added in the configuration file to send emails using System.Net.Mail.

2009-04-06T00:09:00.000-07:00

We all know that there is a BUZZ around the word WEB2.0. This is about the new standards which should be followed by webapplications/websites.

Just have a look at the link below if you have any leisure time and if you feel you play around with the web. This article has a .ppt presentation for u guys and it's very clear and precise on it's topic.....

Thoughts about Web2.0