[Ruby]: Update hash values with Array


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Hi Folks,

In this small tutorial, I am writing a program that updates value of each element in hash with a given array values.
Given that:
h = { h1: 'value1', h2: 'value2', h3: 'value3', h4: 'value4' }
a = [ '1', '2', '3', '4' ]
Where h is a Hash and a is an Array

Output we would like to achieve here is:
h = { h1: 'value1_1', h2: 'value2_2', h3: 'value3_3', h4: 'value4_4' }

Let’s code it:

h = { h1: 'value1', h2: 'value2', h3: 'value3', h4: 'value4' }
a = [ '1', '2', '3', '4' ]

h.each_with_index do |(k, v), i|
break if a.size > h.keys.size

a.each_with_index { |val, index|
if i == index
h[k] = v.to_s + ‘_’ + val.to_s

p h.inspect
# Output => h = { :h1 => “value1_1”, :h2 => “value2_2”, :h3 => “value3_3”, :h4 => “value4_4” }

I’ve tried to minimize the number of loops here. Appreciate your feedback and suggestions.

Happy Coding! :)

Learning RSPEC with Rails 4 (Alpha)


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Hi Folks,

Hope you all are fine and doing good! I am sure most of you, are using TDD for years now. And, once we think of TDD, the first thing comes into our mind is, RSPEC. We all agree that Rspec is a great framework of Test-Driven-Development and its integration with other libraries (like fixtures etc.) is seamless.

With rapid revolution happening in Rails community, Rspec too has evolved over the years, and my motto is to bring this newly developed RSPEC framework in such a way so that, those who are eager to learn TDD can take tips and take this as a learning material. And those, who are planning to migrate can refer to this!

Environments I am using:

  • Ruby 2.1.2
  • Rails 4.2.1
  • Rspec 3.2.0

Idea is to share small code snippets while learning these changes, where we see: what is new. So let’s explore this now:

1. In Rspec 3, the support for ‘should‘ (e.g. foo.should == bar) is deprecated and is no longer supported. Instead of ‘should’, rspec encourages us to use ‘expect‘. Let’s see how it works:

If you try running this example, you’ll get this deprecation warning message:

Deprecation Warnings:

Using `should` from rspec-expectations‘ old `:should` syntax without explicitly enabling the syntax is deprecated. Use the new `:expect` syntax or explicitly enable `:should` with `config.expect_with(:rspec) { |c| c.syntax = :should }` instead

Now, let’s take an example of controller spec. Create a controller with scaffold and write the spec as below:

I’ll cover model, helper and view spec very soon.

Happy Coding :)

[Ruby] Fetching Emails from Microsoft Outlook


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Hi Folks,

Hope everyone is fine and doing good. In this article of mine, I am going to narrate, how you can fetch Emails from your Microsoft Outlook account. I am only going to cover ‘Inbox‘ here. However, the scope of library (Gem) is very vast and you can customize this as per your need.


  • Ruby
  • ViewPoint Gem: gem install viewpoint

For Debugging, I am using viewpoint/logging/config

Hope this helps someone! Keep in touch and Happy Coding :)


Rails 4: Changeset


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Hey Everyone,

I know, I am very late in posting this article, as I didn’t get chance to do much hands-on in Rails 4. But now, that we all are on the same page, let me quickly set the summary here.

Most of us (1) have already started with Rails4, most of them (2) are planning to and most of them (3) are still on Rails 3. So my target audience for this post is #2 and #3. Developers working on Rails4, if they wish to provide any comments/suggestions they are most welcome.

Recently, I got a chance to develop a new application in Rails4. There are many articles available online, which will provide you insight about the changeset in Rails4. But my idea is to give a step by step information, as I continue to work on my existing application. Hence, this post will keep updating at regular intervals.

Folks can take the information from here which is relevant to them.

– If you wish to localize your gems (including Rails4), to your application, you must need to run:

After, rails new {APP_NAME}, then your bundle runs. Once it is finished, run this command:
bundle install --path vendor/gems

This command will create a .bundle folder inside your app. If you open this folder, there is a config file, where path of the gems is defined. You don’t need to define the path again and again. This config file will take care of it.

– If you have a pending migration and you’re trying to browse your application, Rails tells you to do a rake db:migrate before you see you app in action. See attached screenshot for more reference.

Pending Migration Rails4

Including modules in Rails4: If you wish to include any re-usable module in a common place (say application_controller.rb) from your {Rails.root}/lib folder, then you must need to tell your application to load the path. To do this, type:
config.autoload_paths += %W(#{config.root}/lib)

Model.find_or_create_by_{COLUMN_NAMES} is deprecated in Rails4. To use it:
Model.where(col_1: SOME_VALUE, col_2: SOME_VALUE).first_or_create

ActiveRecord::Relation is now changed to #<ActiveRecord::Associations::CollectionProxy []>

– using of conditions while defining associations is no longer supported. Till Rails 3, one can use this syntax:

– Adding Stylesheets: If you’re trying to add any stylesheet into layout, You must need to add it under ‘config/initializers/assets.rb’
Rails4 shows it in a very beautiful way (refer to the attached screenshot)

assets handling in rails4

assets handling in rails4

ActionMailer: deliver_now & deliver_later: Action Mailer is now integrated with Active Job so that you can send emails outside of the request-response cycle, hence the user doesn’t have to wait for the request to complete.

However, if you wish to send the mail straightaway, use deliver_now.


Kick-Off: First Rails 4 Application with HABTM Association


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Hello Folks,

Its been a long time since I’ve not written a post. Now, I realize that it’s time to share some useful snippet with all of you.

Recently, I got a chance to get my hands cleaned with Rails 4. So much is happening around Rails community and with the rapid development of Rails 4, I was finding it bit difficult to keep my momentum going.

Well, leave all this apart. Now, by putting some extra efforts my system is ready with:

Ruby 2.1 & Rails 4.1

In order to start with my first Rails 4 Application, I took HABTM Association (weird, isn’t it?). It came randomly into my mind. However, I will dig into other associations as well with time, but to start with let’s take HABTM association with example.

I assume most of you are aware what changes Rails 4 has introduced. If you’re new to Rails 4 or would like to re-visit the changes, here’s the most useful link I’ve found. Just take a look.

Once you’re sure about changeset in Rails4, let’s draw an example:


  • Ruby 1.9.2+
  • Rails 4.1.0+
  • Traditional Database (MySQL/Postgres)


  • Person Model
  • Communtiy Model
  • A Join Table

Defining the Relationships & creating tables:

For rest of the code-flow (controllers, views) you can download the zip of the application from my GitHub page, run it on your local and see Rails4 HABTM in action.

Happy Coding :)

Add duplicate rows in Excel using Ruby


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Happy New Year Folks,

Few days back a friend of mine came to me and said, “I am a RUBY Programmer and I am stuck in a requirement, wherein I have to read an excel-sheet (that contains multiple records and each record can have multiple entries in it.)”

Think of an example like given in the link: timesheet. It says we have 2 columns: EmployeeID and WorkingHours. Each EmployeeID can have multiple working hours.

Now, I would like to write a small Ruby program that iterate over each record in the excel, combine EmployeeID’s that has multiple entries and add working hours.

Let’s code it then!


  • Ruby 1.9.2 or higher
  • Spreadsheet gem: to read Excel
  • Download timesheet excel from the link above

Happy Coding! :)

Installing mysql2 gem with Ruby 2.0


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Hi Folks,

In this short tutorial of mine, I am going to write down the steps of how you can install mysql2 gem with Ruby2.0 on Windows machine.

Installing Mysql gem is always a big time pain for most of the developers who are working on Windows machine. But thanks to active folks over the internet for their comments, posts.


1. Ruby 2.0.0 pre-installed.
2. DevKit installed
3. gem install rails – command should install all the gems. Return should be success.

Steps to install mysql gem:
1. Go to: http://dev.mysql.com/get/Downloads/Connector-C/mysql-connector-c-noinstall-6.0.2-win32.zip/from/pick, download will start automatically (don’t think at this moment that you’ve a 32 bit or 64 bit operating system.

2. Extract the folder to some place (in my case I am extracting it to C:\mysql-connector-c-noinstall-6.0.2

3. Run this command:

4. Output will return in below manner:

5. If you see this message, create a new Rails4 application, open your Gemfile and use:
gem 'mysql2', '0.3.13'

and run bundle install. Once bundle install runs successfully. You should try:
rake db:create and
rake db:migrate

to ensure that gem is installed correctly.

Hope this will help someone!

Happy Coding!! :-)

Ruby Cheat-Sheet


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Hi Folks,

In this new tutorial, I am going to show you what most of developers/programmers already know, but not able to keep track of such things. I call it as ‘Ruby cheat-sheet‘, you can call it by the name you like.

This will also help those people who have just started learning ‘Ruby’.


  • I will keep on updating this article frequently.
  • Also need your valuable response, if you feel there is a better/easy concept available.
  • If I am not sure of something or don’t know the concept, I am going to highlight that with ‘Red‘ color. Later, you can put your opinion in the comment section and I will update that with your name.
  1. Symbols (e.b :name, :age etc.) as just a convenient way of referencing a name.
  2. You don’t need to per-declare a symbol.
  3. A ‘Class‘ is a combination of state (for example, the name of the animal) and method that use that state (perhaps the method how animal eats).
  4. The standard ruby constructor is ‘new‘.
  5. Every object in Ruby has a unique ‘Object identifier‘ (called as Object ID).
  6. Class have instance methods. These instance methods have access to the object’s instance variables.
  7. Methods are defined with the keyword ‘def‘ followed by method name.
  8. The most common way to create String objects in Ruby is ‘string literals‘. (E.g. “I am a string”, ‘I am another string’)
  9. The logical difference between ‘Single quotes‘ and “Double quotes” in Ruby is the amount of processing Ruby does. In double quote case, Ruby first looks for substitution and replaces them with some binary value. (E.g. puts “Good Night, \nAuthor”)
  10. Global variables: starts with ($) sign: E.g. $name
  11. Instance variable: starts with (@) sign: E.g. @name
  12. Class variables: starts with (@@) sign: E.g. @@name
  13. Class name, module name and Constants: Starts with the uppercase letter: E.g class MyClass, module Login
  14. Array stores collection of object with a key to access them.
  15. An array can have objects of different types.
  16. Hash contains key, value pair.
  17. Ruby treats ‘nil’ as false in conditions.
  18. A regular expression is a way of specifying a pattern of characters to be matched in a string.
  19. The match operator (=~) can be used to match a regular expression against a string.
  20. Yield (yield) is a Ruby method
  21. In Ruby, nil is also an Object
  22. When you run Ruby programs you can actually pass arguments. This concept is called command-line-arguments. For e.g. ruby my_example.rb firstname lastname city.
  23. The initialize method in Ruby lets us set the state of each object. When we call ClassName.new to create a new object, Ruby allocates some memory to hold an UN-initialized object.
  24. When we pass an object to puts based on the class, it writes the name of the object’s class, followed by a colon and a unique identifier.
  25. Ruby gives flexibility to its programmers. You can over-write the default methods. (E.g. def to_s)
  26. attr_reader is the modified way of accessor methods.
  27. attr_accessor provides you to read and write methods. (E.g. attr_accessor :age)
  28. Virtual attributes**
  29. require‘, ‘require_relative‘ & ‘load
  30. Access Controls – ‘Public‘, ‘Private‘ & Protected
  31. In ‘Ruby’ a variable is not an Object. It is simply reference to an Object.
  32. initialize‘ is a private method in Ruby.
  33. Block, Procs and Lambda are ways of grouping code we want to run. These are examples of closure in Ruby.
  34. Both Proc and Lambda are Proc Objects.
  35. Lambda check the number of arguments and throws argument error, whereas Proc does not.
  36. In “Inheritance“, if class B inherits the property of class A, then all the methods of class A becomes the member of class B.
    • Assuming child = Child.new; then child.superclass => Parent
    • parent.superclass => Object
    • Object.superclass => BasicObject
    • BasicObject.superclass => nil
  37. Modules: is a way of grouping together Methods, Classes and Constants.
    • Provide namespaces and prevent name clashes.
    • Supports the mix-in functionality.
    • A Module is not a class.
    • A Module cannot have instances.
    • We can always include a module in a class definition – After doing that all module instance methods are suddenly becomes available as methods in the class. They get mix-in.
    • mix-in modules don’t use instance variable directly. They use accessors to retrieve data.
  38. self.method_name: Gives you access to the current object.
  39. begin-rescue blockUse for exception handling.

Displaying Something from The Database


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Guys in this tutorial I will explain you how to fetch values from the database and show those in a Table format.

Here I assumed one thing, that the user is logged in. and that user has the rights to delete a particular record from the table.

NOTE: This tutorial is very old. But will glimpse you how you can format your data in a structured manner.

So are you Guys Ready???? Then Let’s Start……..

Note: This will start the session of that particular user.

What a leader should learn from M.S. Dhoni


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M.S. Dhoni, yes the world knows him! What he has achieved so far in his cricketing career, nobody else does. He is Indian skipper, known as ‘Maahi’, ‘Capatin Cool’ and lots of other names.

Well, after India became T20 champions and then in 2011 became World champions, soon after that I started hating Dhoni. Trust me, but it’s true. Somewhere in my mind, I thought he is arrogant, proudy and a person who doesn’t respect his seniors and don’t give any value to his team. Trust me when I say this, I mean it.

But in June, 24th 2013, I’ve witnessed of another glory/achivement of Indian team and this time Indian team won the ICC champions trophy 2013 cup. And the Man in highlight is again the Indian skipper M.S. Dhoni.

He was given a team of those players who have either debuting their ODI career or played very limited number of ODI’s or have no experience of playing overseas matches. But in the end, everyone contributed and delivered their best. All credit goes to ‘Maahi’.

What he has done? He showed his trust in #IshantSharma and he proved to be the Game changer/Turning point for #TeamIndia.

* What mantra he (Dhoni) is using?
* Any divine power on him?
* Any Totka he do before every match starts?

Well, the answer to each and every question lies in his Captaincy skills. The way he manages his team, the level of trust he has and the decision making power, the ability to motivate team memeber even if he is not performing and the ability to stay calm, makes him what he is now.

In this article, I am going to talk about what we can learn from Dhoni, how we can adapt some extra ordinary skills and improve ourselves.

Personally, I won’t be giving a lecture kind of thing here.. We all want to be leaders and with the examples like this we can be the masters of our era.


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