Our morning standups are now starting at 9:30 and we were given our first project assignment which was to find the difference between:

  1. rails g controller name [arg1] vs rails g controller name
  2. rails g model name [arg] vs rails g model name

My pair partner and I decided to time box this to an hour max and you can see below what we’ve discovered.

  • The controller generator is expecting parameters in the form of generate (short 'g') controller ControllerName action1 action2. So if we make a Greetings controller with an action of hello. We will run:

      bin/rails generate controller Greetings hello
    create  app/controllers/greetings_controller.rb
      route  get "greetings/hello"
     invoke  erb
     create    app/views/greetings
     create    app/views/greetings/hello.html.erb
     invoke  test_unit
     create    test/controllers/greetings_controller_test.rb
     invoke  helper
     create    app/helpers/greetings_helper.rb
     invoke  assets
     invoke    coffee
     create      app/assets/javascripts/greetings.js.coffee
     invoke    scss
     create      app/assets/stylesheets/greetings.css.scss

    This will create the controller file and create a method for us called hello which is our action and as you can see from above we also have a view file for it. You can the method in our controller below:

      class GreetingsController < ApplicationController
    def hello
    end
  end

Saves us time! If we run it without an argument i.e. action, it will just generate an empty controller and no view files.

  • The module generator is expecting parameters in the form of generate model ModelName arg1:type arg2:type etc. So we will run:

      rails g model minion eyes:integer colour:text
       invoke  active_record
       create    db/migrate/20151013092345_create_minions.rb
       create    app/models/minion.rb

And it will create a migration file which is a modification of our database. In this case, as we don’t have a minion’s table it will create it for us with two columns eyes, taking a number (integer) value, and colour, which will take a text value. It will also create the action model for the minion. For a reference, our migration file code is looking like this:

class CreateMinions < ActiveRecord::Migration
 def change
   create_table :minions do |t|
     t.integer :eyes
     t.text :colour

     t.timestamps null: false
   end
 end
end

On the other hand, if we run rails g model minion without an argument, it will generate an empty table and a model.

Dan & Zhivko