Why controllers handle requests in Ruby on Rails

Introduction

Controllers in Rails act like traffic managers. They receive requests from users and decide what to do next, such as showing a page or saving data.

When a user clicks a link or submits a form on a website

When the app needs to decide which page or data to show based on user actions

When you want to organize how your app responds to different user requests

When you need to connect user input with the right part of your app logic

When you want to keep your app code clean by separating request handling from data and views

Syntax

Ruby on Rails

class ControllerNameController < ApplicationController
  def action_name
    # code to handle request
  end
end

Controllers are Ruby classes ending with 'Controller'.

Each method inside a controller is called an action and handles a specific request.

Examples

This controller action shows a list of all products when the user visits the products page.

Ruby on Rails

class ProductsController < ApplicationController
  def index
    @products = Product.all
  end
end

This action finds and shows a specific user based on the ID from the URL.

Ruby on Rails

class UsersController < ApplicationController
  def show
    @user = User.find(params[:id])
  end
end

Sample Program

This simple controller has one action 'hello' that sets a message to show on the page.

Ruby on Rails

class GreetingsController < ApplicationController
  def hello
    @message = "Hello, welcome to our site!"
  end
end

Important Notes

Controllers keep your app organized by handling user requests separately from data and views.

Each action corresponds to a URL route that users can visit.

Controllers often use parameters from the request to find or save data.

Summary

Controllers handle user requests and decide what the app should do.

They keep your app organized by separating request logic from data and views.

Each action in a controller responds to a specific user request or URL.