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10 Useful Ruby On Rails Gems We Couldn't Live Without

  • By Nagarani Gorantla
  • August 28, 2018

Agira always has some strong fond with Ruby On Rails right from the beginning because Agira always has had experienced the power of Ruby On Rails in so many projects for years.
In order to acquire that level of success in Ruby On Rails, we require some rapidity and intelligence in our working style. That’s where the Ruby On Rails Gems plays a major role in eliminating some frightening issues and proclaims its heavenly supports for us during the development.
So today am planning to list some of the top 10 useful Gems which we’re using in our projects and we hope that could ease your development of Ruby On Rails applications.

  • PRY

Let me introduce you to every gem along with its features and will see how we can use it in our projects too.


While writing the code, integrating some libraries or binding some gems doesn’t integrate properly so during that time continuously we used to get errors. So to eliminate this kind of issue and also for debugging the errors in our code PRY would be the best choice that you can use without a doubt. By using PRY, we are able to implement step-by-step code debugging by setting the breakpoints.

Features Of PRY

Let’s look into some of the best features of PRY,

  • Syntax highlighting
  • Command shell integration (start editors, run git, and rake from within Pry)
  • Navigation around the state (cd, ls and friends)
  • Runtime invocation (use Pry as developer console or debugger)
  • Exotic object support (Basic Object Instances, Classes …)
  • Powerful and flexible command system, etc

To use this, add this following line to your Gemfile,

    # Call 'binding.pry' anywhere in the code for debugger console
    gem ‘pry,’ ‘0.11.3'

Click here to learn more about PRY.


Usually, when we are building an application on social networks or when we build a dependency-based e-commerce solution then we must need to log in the page or can log in through social media. Here obviously we will be in need to provide authentication and authorization for the specific application.
To solve this, some developers go for their own code for user authentication whereas most of the developers prefer to go for Ruby gems and there DEVISE gem would be the best choice for user authentication which makes your work easy and effective.
DEVISE has 10 modules,

  • Database Authenticatable
  • Omniauthable
  • Confirmable
  • Recoverable
  • Registrable
  • Rememberable
  • Trackable
  • Timeoutable
  • Validatable
  • Lockable

To use this, here you can add this line in your Gemfile,

    # Use devise for authentication
    gem ‘devise’

Click here to learn more about DEVISE


This Gem will especially help us while building complex applications in which users allowed to have multiple rules and there you might need to set the access restrictions for specific users. In this kind of situation, this gem will help us to be free in setting up the access restrictions for each and you could maintain all in one place.


The first one is the “Authorizations definition library” this will allow us to define the rules for users and also it will enable the Helpers to access different objects and provides helpers to check for those permissions.
Controller helpers that help to simplify the code in Rails controllers by performing the loading and it will check the permissions of models in controllers.
Now, just add this line in your Gemfile and see what happens,

gem ‘cancancan’, ‘2.2.0’

Click here to learn more about CANCANCAN


When you need to keep some longer running actions on background tasks then in such type of cases the delayed_job gem would be the best for you. Because directly it will get extracted from Shopify where the job table is responsible for the multiple tasks.


  • Sending massive newsletters
  • Image resizing
  • http downloads
  • updating smart collections
  • Updating solr, our search server, after product changes
  • batch imports
  • spam checks

Add this line in your Gemfile,

    # delayed_job supports multiple backends for storing the job queue
    gem 'delayed_job_active_record'

Learn more about DELAYED JOB here


When we face the clumsy situation in setting up email delivery in the development environment and that’s where the gem letter_opener is a will get in. Yes! This will allow us to preview the emails which are sent from an application and dropped straight into your browser’s tab. This will greatly help us in our applications for sending emails to the multiple accounts when the email requires a quick email preview. So, With letter_opener, you no need to wait for an email to deliver to your email inbox every time. And, you no longer need to worry about the emails that are accidentally sent as a test email to someone else’s. Because LETTER OPENER will take care of it.
Add this line in your Gemfile to use LETTER OPENER,

    # Spring speeds up development by keeping an application running in background.
    gem 'letter_opener', '1.6.0'

Click here to learn more about LETTER OPENER


If you want to write the unit test cases for your application, this gem will help you to integrate the RSpec framework into the Rails project by generating the required configuration files and spec helpers. This testing framework used in both BDD and TDD environments. To put it straight, the syntax of RSPEC RAILS would be neat and descriptive.
Use the below line to your Gemfile to access RSPEC RAILS,

    gem 'rspec-rails', '3.8.0'

Learn more about RSPEC-RAILS here.

Also Read

10 Useful Tips & Tricks for Ruby On Rails Developers


Active Admin is a framework for creating administration style interfaces. It abstracts common business application patterns to make it simple for developers to implement beautiful and elegant interfaces with very little effort.

Features Of Active Admin

  • User Authentication
  • Global Navigation
  • Scopes
  • Index Styles
  • Action Items
  • Filters
  • Sidebar Sections
  • APIS and Downloads

To access this, add this line in your Gemfile

    gem 'activeadmin', '1.3.1'

Check more about ACTIVE ADMIN here


Storing the application configuration keys and values in the environment is widely used practice derived from the principle of twelve-factor application, by doing like this, you are able to secure your sensitive data like passwords and API keys outside the code repository, but still, the data will be available during the execution. However, sometimes it is not efficient to set environment variables on the development machine or continuing integration server to run multiple applications. In this case, the dotenv-rails gem would be a good choice to use to protect your sensitive information. This gem will load all the variables from .env file which resides outside of your root project. So, you can able to keep up to secure your application’s keys.
Add this line in Gemfile,

    gem 'dotenv-rails', '2.5.0'

Read more about DOTENV-RAILS

Active Merchant

Active Merchant is RubyGem written and maintained by Shopify. Its main goal is to provide a simple unified API to access the dozens of different payment gateways with diverse internal APIs.
It’s specially developed to use in Ruby on Rails web applications and it can seamlessly help us to integrate it as a plugin also and finally last but not least it will extend its great support when we’re using it as a stand-alone library.
Add this line in your Gemfile,

    gem 'activemerchant', '1.81.0'

Learn more about ACTIVE MERCHANT here

Rails Best Practices

Rails_best_practices is a code metric tool that used to analyze the code to find the code smells, pieces of code that aren’t technically bugged, but which may lead to the creepy software issues in the future. Here come the Rails_best_practices that will, fortunately, offer suggestions to improve your code – for example, suggesting the removal of tabs, annotation of models, or additional database indexes. With the support of this Gem, we can easily share the results of the analysis with our collaborators and can also track our results over time to see how your code has improved.
Add the following line in your Gemfile,

     gem 'rails_best_practices', '1.19.3'

Click here to read more about rails best practices
I hope this helps you! Similarly, you can learn more about interesting on latest technologies, never miss out on anything from our largest blog portal where you can get continuous blog updates & latest posts about all the latest technologies which would be perfect for your 15 minutes tea break! In case if you’re a newbie then don’t forget to subscribe to us to get the latest updates from diverse technologies. For more inquiries reach us via

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Nagarani Gorantla

Software Engineer having 2 years of experience in Web Development, hands on expertise in Ruby, Ruby On Rails, Angular and CMS. An Active ally of Social services and Blood camps.