Action methods in Ruby on Rails - Mini Project: Build & Apply

Building Action Methods in Rails Controller

📖 Scenario: You are creating a simple Rails application to manage a list of books. Each book has a title and an author. You want to build action methods in a controller to show a list of books and display details of a single book.

🎯 Goal: Build a Rails controller with action methods index and show to list all books and show details of one book.

📋 What You'll Learn

Create a BooksController class

Add an index action method that sets @books to all books

Add a show action method that finds a book by params[:id] and sets @book

Use Rails conventions for controller and action methods

💡 Why This Matters

🌍 Real World

Controllers in Rails handle user requests and prepare data for views. Action methods like index and show are common for listing and displaying records.

💼 Career

Understanding how to write action methods in Rails controllers is essential for backend web development roles using Ruby on Rails.

1

Create BooksController class

Create a Rails controller class called BooksController that inherits from ApplicationController.

Ruby on Rails

# Your code here

Need a hint?

Controllers in Rails are classes that inherit from ApplicationController.

2

Add index action method

Inside the BooksController class, add an index action method that sets an instance variable @books to Book.all.

Ruby on Rails

class BooksController 
  # Your code here
end

Need a hint?

Action methods are defined with def and set instance variables for views.

3

Add show action method

Inside the BooksController class, add a show action method that sets an instance variable @book by finding a book with Book.find(params[:id]).

Ruby on Rails

class BooksController < ApplicationController
  def index
    @books = Book.all
  end

  # Your code here
end

Need a hint?

The show action finds a single record using params[:id].

4

Complete controller with both actions

Ensure the BooksController class contains both index and show action methods exactly as specified.

Ruby on Rails

class BooksController < ApplicationController
  def index
    @books = Book.all
  end

  def show
    @book = Book.find(params[:id])
  end
end
# Verify both actions are present

Need a hint?

Double-check both action methods are inside the controller class.