Introduction to Ruby on Rails

Ruby on Rails is a web application framework that allows developers to create database-backed web applications according to the Model-View-Controller (MVC) pattern. It is written in the Ruby programming language and is designed to make programming web applications easier by making assumptions about what every developer needs to get started. In this blog post, I will cover 5 topics related to Ruby on Rails to provide anyone new to the framework a comprehensive overview of the framework, - let's get started.

Model-View-Controller (MVC) Pattern

The Model-View-Controller (MVC) pattern is a design pattern used in software engineering to separate the application logic from the user interface. It consists of three components:

  • Model: The model represents the data and the business logic of the application. It interacts with the database and performs all the necessary calculations and validations.
  • View: The view is responsible for presenting the data to the user. It is the user interface of the application and is responsible for displaying the data in a way that is easy to understand.
  • Controller: The controller is the intermediary between the model and the view. It receives input from the user and updates the model accordingly. It also updates the view to reflect the changes made to the model.

In Ruby on Rails, the MVC pattern is used to structure web applications. The model represents the database schema, the view represents the HTML templates, and the controller handles the user input and updates the model and view accordingly. This separation of concerns makes it easier to maintain and modify the application over time.

Active Record

Active Record is the Object-Relational Mapping (ORM) layer provided by Ruby on Rails. It is responsible for mapping database tables to Ruby classes and vice versa. Active Record provides an easy-to-use interface for interacting with databases and eliminates the need for writing SQL queries.

Active Record provides a number of features, including:

  • Associations: Associations allow you to define relationships between different models. For example, you can define a one-to-many relationship between a user and their posts.
  • Validations: Validations allow you to ensure that the data being saved to the database is valid. For example, you can ensure that a user's email address is unique.
  • Callbacks: Callbacks allow you to execute code at certain points in the lifecycle of an Active Record object. For example, you can execute code before or after an object is saved to the database.

In Ruby on Rails, Active Record is used to interact with databases. It provides an easy-to-use interface for performing CRUD (Create, Read, Update, Delete) operations on database tables.


Routing is the process of mapping URLs to controller actions. In Ruby on Rails, routing is handled by the router, which is responsible for determining which controller and action should handle a particular request.

Routes are defined in the config/routes.rb file. The routes.rb file contains a set of rules that map URLs to controller actions. For example, the following rule maps the root URL to the welcome#index action:

root 'welcome#index'

This rule tells the router to map the root URL (/) to the welcome controller and the index action.

Routes can also include parameters, which are used to pass data to the controller. For example, the following rule maps the URL /users/1 to the users#show action:

get '/users/:id', to: 'users#show'

This rule tells the router to map the URL /users/1 to the users controller and the show action, and to pass the value 1 as the id parameter.

In Ruby on Rails, routing is used to map URLs to controller actions. It provides a flexible and powerful way to handle requests and to build RESTful web applications.


Views are responsible for generating HTML responses to requests. In Ruby on Rails, views are typically written in ERB (Embedded Ruby), which is the default templating language, it allows you to embed Ruby code in HTML.

Views are associated with controllers and actions. For example, the index action in the welcome controller might have a corresponding index.html.erb view file. When a request is made to the welcome#index action, the index.html.erb view file is rendered and the resulting HTML is sent back to the client.

Views can also include partials, which are reusable pieces of HTML that can be included in other views. For example, you might have a _header.html.erb partial that contains the header of your website, which is included in every view.

In Ruby on Rails, views are used to generate HTML responses to requests. They provide a flexible and powerful way to generate dynamic content and to build web applications.


Testing is the process of verifying that your application works as expected. In Ruby on Rails, testing is typically done using the built-in testing framework called MiniTest, there are other testing library, like the popular RSpec testing library.

There are three main types of tests in Ruby on Rails: unit tests, functional tests, and integration tests. Unit tests are used to test individual components of your application, such as models and controllers. Functional tests are used to test the behavior of your application from the user's perspective, such as testing the login process. Integration tests are used to test the interaction between different components of your application, such as testing the interaction between the front-end and the back-end.

Testing is an important part of the development process in Ruby on Rails. It helps to ensure that your application works as expected and that changes to your code do not introduce new bugs or regressions. By writing tests, you can catch errors early in the development process and avoid costly mistakes down the line.


In this blog post, I have covered five important topics related to Ruby on Rails. I have discussed the basics of Ruby on Rails, including its architecture and key features. I have also covered the Model-View-Controller (MVC) design pattern, which is a fundamental concept in Ruby on Rails development. Additionally, I have discussed the importance of testing in Ruby on Rails development and have provided an overview of the different types of tests that are commonly used. Finally, I have discussed the importance of security in Ruby on Rails development and have provided some best practices for securing your Ruby on Rails applications.

Ruby on Rails is a powerful web application framework with a lot of advantages. It offers simplicity, efficiency, security, and scalability, making it an ideal choice for many developers. I hope that this blog post has provided you with a general overview and foundation for understanding Ruby on Rails. If you're feeling adventurous the best place to start is the Rails Documation