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Creating A New Controller

Getting Started

1. Create your project

2. View your project in the browser. You should see a default page.

Create your Controller

Controllers are classes that inherit from ApplicationController.

Controllers in Rails have one or many actions. Each action is defined as a method inside the controller. Some standard actions are index, create, new, edit, show, update, and destroy. But you're not limited to using those names.

We will start with index, which can be used to display the main page in your application.

3. Create your first controller called HomeController.

Create a controller file in the app/controller folder. The file should always be named with lower case letters and underscores.

app/controllers/home_controller.rb

4. Create your controller, with an empty index method. In the home_controller.rb file add:

class HomeController < ApplicationController
  def index
  end
end

Create your View

5. Create your first view, to be associated with the Home controller and the index action.

Create a new folder in app/views. The folder name should always be lower case and the name of your controller.

app/views/home

Create a file for your first action in the app/views/home folder. The filename should always be lower case and the name of the action.

app/views/home/index.html.rb

Each view created is associated with one controller action. You don't even really need to define a method in the associated controller: as long as the associated controller and route exist, Rails will pretend that the method exists, and is empty, and render as such.

Create your Route

A route is a path that points to an action for a specific controller. This controller and action pair (often stylized as controller#action) also indicates which view should be used, via the file naming conventions mentioned above.

6. Edit routes.rb so that the base url points to your application entry point

root 'home#index'

NOTE: This says that your base url (i.e. root) should use the index action of the home controller. The view used will be the file in the app/views/home folder with name index (e.g. app/views/home/index.html.erb).

Each subsequent route should be defined in a similar way:

get 'about' => 'home#about'

NOTE: This says that the base url with /about on the end will direct to the about action in the home controller.

Test your new Controller

7. Go back to your project in the browser and confirm that on the root path you now see the content from your index.html.erb file instead of the default Rails welcome page.

8. Add an about action to the Home controller and test that you can see it at the /about path in the web browser.