17 August 2015
My Travel Companions
I did some researches in the Internet and decided to take the following with me.
1. Osprey Farpoint 40 Liter Backpack
2. Two pants (Purchased from Grameen UNIQLO)
3. Three shirts
4. Two Lungi
5. TwoT-shirts
6. A warm Jacket
7. A 700 ml water bottle
8. A Waterproof transparent bag
9. A sleeping bag
10. A lightweight towel
11. A shorts
12. A trekking Shoe
13 A Sandal
14. Three pairs of socks and underwear
15. A power bank
16. Laptop
17. Mobile
What do you think about the list? Have I missed anything? Have I decided to take something unimportant?
What do you usually take while going for a backpacking tour somewhere?
17 June 2011
Display Avatar in Ruby on Rails application
In this example I will show you a way to display Gravatar in your Ruby on Rails web application.
First I will write a helper method which will return an image url for displaying Avatar. Gravater, id is simply the MD5 hexdigest of the email address. So the line returning avatar id will be:
gravatar_id = Digest::MD5.hexdigest(user.email.downcase)
I would like to display the avatar as 48x48, which is the usual size of a twitter display image. Also, I want to show a default image url if avatar is not shown. For these two, we need to pass some extra parameters. The method will look like:
def avatar_url(user) default_url = "#{root_url}images/default-image.jpg" if(user.present?) gravatar_id = Digest::MD5.hexdigest(user.email.downcase) return "http://gravatar.com/avatar/#{gravatar_id}.png?s=48&d=#{CGI.escape(default_url)}" else return default_url end endIn your view:
<%= link_to(image_tag(avatar_url(user)), user_path(user.id))%>
The above line, will show the avatar and will take you to the show method of UsersController if you click on it.
You can also choose from an user to display his avatar from gravatar or your local file system. All you need to do is to have a boolean field 'avatar' in your User table and re-arrange the logic in avatar_url method.
It's that simple! Happy coding!!
05 March 2011
SEO friendly URL in ruby on rails and friendly_id
By default Rails generate URL with ID. In short to_param method returns a string, which Action Pack uses for constructing an URL to this object. The default implementation returns records’ id as a string.
Suppose, we have a Category model. The routes.rb will look like:
map.resources :categoriesIn categories.rb controller:
@category = Category.find(1)In view index.html.erb:
<%=link_to(@category.title,category_path(@category))%>This will generate the URL: /category/1
While working on building a website Khan Academy In Bangla as a part of the translation project of Khan Academy , I realized that a SEO friendly URL is mandatory. In this website, I have categories like physics, biology or math and tutorials under each category. In order to make the user friendly URL I needed to overwrite to_param method in model.
In order to make it SEO friendly, in Category.rb model I added the line:
def to_param "#{id}-#{title.downcase.gsub(/[^a-zA-Z0-9]+/, '-').gsub(/-{2,}/, '-').gsub(/^-|-$/, '')}" endThe regular expression will remove any special character. It generates the url: /category/1-biology. Looks better, right?
Although the URL has become SEO friendly now but this method has some drawbacks. To summarize some:
1. It appends the id with the name. If we remove ID, then maintaining uniqueness will be a problem
2. If the title field is edited then the URL will be changed causing SEO to break.
3. For a large application, it will not be feasible to overwrite to_param in tons of model.
In this point, I found a nice plugin/gem to make all these pretty simple and it is friedly_id . It will do all the work for you with some simple steps. For my system what I did were:
1. Install the gem:
gem install friendly_id2. In environment.rb include the gem.
require 'friendly_id'3. Generate friendly_id by going to my application directory:
cd khanacademybangla script/generate friendly_id4. Run the migration
rake db:migrate5. Add has_friendly_id to the models which I am looking for to generate user friendly id
class Category < ActiveRecord::Base has_friendly_id :title, :use_slug => true end6. Run a rake task to generate slugs for existing records:
rake friendly_id:make_slugs MODEL=ModelNameFor my example it was:
rake friendly_id:make_slugs MODEL=categoryThat’s it! Now we will be able to see a completely SEO friendly url: /category/biology
I am yet to push my code to production! You need to wait till tomorrow to see it live.
13 January 2010
Displaying status feed of twitter in Rails
Couple of days ago I needed to show twitter status in a rails application. The specification was to show the last 5 status of a twitter account. Twitter itself has a good API. But I used twitter gem which left me to do just a couple of lines of code.
Twitter gem supports both OAuth and HTTP Auth. I used HTTP Auth for authentication. Let me dig in to code.
First of all, install twitter gem.
gem install twitterLoad ruby gem to environment.rb.
require 'twitter'
Then perform the authentication using HTTP Auth. You need to provide your user id and password of the twitter account. You should read this from a config file. For the simplicity I am placing it at code.
def twitter_feed httpauth = Twitter::HTTPAuth.new(‘twitter_account_name’, ‘twitter_account_password’) twitter_client = Twitter::Base.new(httpauth) @latest_status_feeds = twitter_client.user_timeline[0..4] if twitter_client.present? #it will show most recent 5 status. If you would like to show recent 20 don't put any bar. render :partial=>"twitter_feed" end
In twitter_feed partial you can display the text using some properties.
<h4>Latest Tweet</h4> <%if @latest_status_feeds.present?%> <% @latest_status_feeds.each do | @latest_status_feed|%> <p>"<%= @latest_status_feed.text %>"<br /><span class="time" style="font-size:11px;font-style:italic;"> <%= convert_date(@latest_status_feed.created_at.to_date) %></span></p> <%end%> <%end%>
This will show the last 5 status from your twitter feed.
If you would like to show the twitter feeds of your friends, the following tweak is needed to be made:
@friends_feeds = twitter_client.friends_timeline
You can display from the view in the same way!
That's it! Pretty simple, yeah? Happy coding.
31 December 2009
Presentation on bad smells in code
Most of you must have read the famous book on “Refactoring” written by Martin Fowler. Based on this book and and my fellow colleague Rashed Kibria presented at the BASIS, titled as “Bad Smells in code (Part-1)”. We have shared the document. You can take a look at it.
Bad Smell in Codes-1