Monday, September 21, 2009

Showing unread posts/comments: An example of rails ActiveRecord 'touch'

I worked on the following story:-
"As a partner, when I visit a project's dashboard I want to see five most recently started or updated discussion threads with number of unread comments, if any. If any of these are new, I want to see them in a highlighted view. Next, if I open the thread, I want to see all new comments in a highlighted view as well. However, once seen, the threads/comments should no longer be highlighted from the rest."
I used the following steps to implement this.

Step#1: Added a model MessageReadTime (message_id, user_id, last_read_at)
class Message 
has_many :messages_read_times 
Step#2: Added filters in the messages_controller
after_filter :update_message_read_time, :only => [:show]
def update_message_read_time
read_time = MessageReadTime.find_or_create_by_message_id_and_user_id( params[:id],
read_time.last_read_at =!
Step#3: Added :touch=>true and unread? function in Comment class
class Comment
belongs_to :message, :touch => true
def unread?(user)
read_time = self.message.message_read_times.find_by_user_id(user_id)
return true unless(read_time)
return read_time.last_read_at < (updated_at || created_at) end end
Step#4: Added unread_comments method in Message class like this
class Message
def unread_comments(user)
self.comments.collect{|comment| comment.unread?(user) ? comment : nil }.compact

def unread?(user)
read_time = self.message_read_times.find_by_user_id(
return true unless read_time
return self.updated_at >= read_time.last_read_at
This is it! If you know a better way to do this, lets discuss in the comments. You are also welcome to share your thoughts/suggestions :-)

Thursday, September 17, 2009

Some useful plugins for RoR projects

Previously I used a few plugins in RoR projects including ScrumPad. On a more recent work, I found the following plugins to be really useful and easy to get started:-

1. I18n: Rails Internationalization
2. Seed-fu: Initial data loading for application  (e.g. admin user, product categories)
Tutorial A support is now built in for Rails 2.3.4
3. Thinking-sphinx: Full text search
4. Paperclip: File and image upload made hassle free

If you looking for any of the above for features in your app, I suggest you give these plugins a try. It should be good for most of the apps unless you have some really unique needs.

Write in comments if you would like to share some other useful RoR plugins.

Wednesday, September 09, 2009

The CGI story on agile scaling success on a large project

This intro is from the presenters:-
PAS was a joint venture development initiative by 4 major oil and gas
companies and CGI. Devon, Encana, Husky and Talisman joined with CGI to
develop a new Production and Revenue Application. Each company put 3 senior
business resources on the project. The development component of the PAS
initiative cost $35M over 5 years with up to 90 people on the team. This
presentation is on how we used Agile to achieve this mammoth undertaking.

The product is currently running in production at 5 major oil and gas
companies with great reviews. It is also in production for several mid and
smaller sized companies. CGI is currently marketing the product.
This was my first ever meet with the Calgary agile methods user group, CAMUG and it was a great experience. Off late, I have been looking for my graduate research topic on agile methods, especially around scaling agile beyond a single team and this was just a perfect session for me.

I noted down a few of their discussed topics that I would like to share with my readers:
  1. The project continued in dev mode for 5 years, a $35M project.
  2. It started with only 3 members and extended to a team of 90 following Scrum+XP.
  3. The project had 5 sponsoring companies or clients.
  4. They had 6 teams working in the same sprint cycles.
  5. In each team, there were significant members from the business working full time with the team onsite and in the same open-space arrangement.
  6. They had some 3000+ unit tests and also 300+ acceptance test.
  7. They automated all repetitive tests.
  8. The had external experts visiting them from time to time. Eric Evans once visited them and helped them getting better grasp on Domain Driven Design.
  9. There had been a $800K and one month deviation from the projected cost and timeline.
They also discussed some issues related to working in a multi-team, multi-client project. I remember the following ones:-
  1. They had to balance between features/bug fixes.
  2. The deployment was taken care of by the respective sponsors, not the teams.
  3. They had issues with sprint backlog management.
They highlighted some aspects with great emphasis:-
  1. Open communication is the key to success.
  2. Onsite and full time real user availability is very important for such a big project.
  3. Automated tests, partial pair programming and continuous integration is a big plus.
  4. Staying co-located was really helpful.
What about scaling beyond?
  1. I asked them, if they felt it would still be a similar success if there had been 12 teams or even more with 200 people or so. They said, it would be challenging. But in response, they also said, following waterfall would make life much harder with such a big team, if at all it could be a success at the first place! Yes, I also believe this.
  2. One of the audiences asked if they outsourced a part of the project and the response was 'No'. CGI has a big team in India with a very high CMM ranking, but the project manager and asst. project manager said, it would be much difficult for differing time zones. Also, it would be difficult to transfer the knowledge as well as replicate the value of onsite client presence. The development manager also added that, the cultural difference between an agile and CMM setup would also been an issue if they had to go for the off-shore team.
The session was much more eventful than what I could compile. So, if you are anywhere near Calgary and interested about meeting agile practitioners from the industry, lets meet at the next meet! 


Sunday, September 06, 2009

A new home at Calgary and starting days

We relocated to the northwest section of Calgary, Alberta on the 26th August. I am new to this part of the world and traveling to this opposite time zone (GMT+6 to GMT-6) took around 33 hours. Did you ever take a flight on Qatar? Not? I recommend it. They offer best foods for your south asian delight. My route was Dhaka - Doha - London - Calgary. I enjoyed the trip (don't tell anyone, I was a bit scared when traveling over the Atlantic :-))

The city of Calgary is really eye soothing green during this season. The little homes and lawns look fabulous in my eyes. People here celebrate the summer in style, you will see large family camping vans every now and then. So far the people here are also very friendly and welcoming towards new comers. It has been a good experience and hopefully coming days will be even better!

On the 4th, I attended the graduate orientation program and met a lot of people. It was nice to know that the University of Calgary is equipped with all amenities required for an excellent graduate education. I am looking forward to use my free pass to the swimming pool! It'll be fun!

I met my supervisor, Frank, and also people at my Lab. My next duty will be to select a topic for my research by the end of this year. But the earlier it is selected, the better it is. Let me know if you have a good idea on your heads around agile software process/tools or digital tabletops.

My upcoming posts will be a mix of my graduate studies and my software related works. Also, I will be TAing and wish to share some of my teaching experience as well. Stay tuned!