Rails generate command 5.0

Examples

• 1

  Rails Generate Migration

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  1

  You can generate a rails migration file from the console using this formula:

  rails generate migration AddFieldsToModels field_name:field_type field_name_2:field_type

  For example, if you wanted to add the first_name and last_name fields to the users table, you can do this:

  rails generate migration AddNamesToUsers last_name:string first_name:string

  Rails will create this file:

  class AddNamesToUsers < ActiveRecord::Migration[5.0]
    def change
      add_column :users, :last_name, :string
      add_column :users, :first_name, :string
    end
  end
  

  Now, migrate the database by running rake db:migrate in the console.

  Note: For even less typing, you can replace generate with g.

  edited yesterday

  

  
• 1

  rails generate model

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  1

  To easily generate an ActiveRecord model that inherits from the right class in Rails and automagically creates the correct db migrations & boilerplate test files for your model, simply do:

  rails generate model NAME lots_of_options
  

  Options include the name of the column and the type (e.g. name:string or body:text).

  You can also setup foreign keys easily by doing belongs_to:model_name.

  So say you wanted to setup a User model that has a username, email and belongs to a School, you could do something like this:

  rails generate model User username:string email:string school:belongs_to
  

  You could also simply do rails g instead of spelling out rails generate. So the above would look like this:

  rails g model User username:string email:string school:belongs_to
  

  created Jul 22 at 15:57

  
• 0

  rails generate controller

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  we can easily generate controller with rails g controller command.

  example

  $ bin/rails generate controller controller_name
  

  The controller generator is expecting parameters in the form of generate controller ControllerName action1 action2.

  Let's make a Greetings controller with an action of hello, which will say something nice to us.

  $ 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.coffee
       invoke    scss
       create      app/assets/stylesheets/greetings.scss
  

  it will generate controller file, a view file, a functional test file, a helper for the view, a JavaScript file and a stylesheet file, as well as adding the routes for each action to routes.rb.

  edited yesterday

  

  
• 0

  rails generate scaffold

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  0

  DISCLAIMER: Scaffolding is not recommended unless it's for very conventional CRUD apps/testing. This may generate a lot of files(views/models/controllers) that are not needed in your web application thus causing headaches(bad :().

  You can generate a fully working scaffold for a new object, including model, controller, views, assets, and tests by using the rails g scaffold command.

  For example:

  $ rails g scaffold Widget name:string price:decimal
      invoke  active_record
      create    db/migrate/20160722171221_create_widgets.rb
      create    app/models/widget.rb
      invoke    test_unit
      create      test/models/widget_test.rb
      create      test/fixtures/widgets.yml
      invoke  resource_route
       route    resources :widgets
      invoke  scaffold_controller
      create    app/controllers/widgets_controller.rb
      invoke    erb
      create      app/views/widgets
      create      app/views/widgets/index.html.erb
      create      app/views/widgets/edit.html.erb
      create      app/views/widgets/show.html.erb
      create      app/views/widgets/new.html.erb
      create      app/views/widgets/_form.html.erb
      invoke    test_unit
      create      test/controllers/widgets_controller_test.rb
      invoke    helper
      create      app/helpers/widgets_helper.rb
      invoke    jbuilder
      create      app/views/widgets/index.json.jbuilder
      create      app/views/widgets/show.json.jbuilder
      invoke  assets
      invoke    javascript
      create      app/assets/javascripts/widgets.js
      invoke    scss
      create      app/assets/stylesheets/widgets.scss
  

  Then you can run rake db:migrate to set up the database table.

  Then you can visit http://localhost:3000/widgets and you'll see a fully functional CRUD scaffold.

  edited Jul 23 at 4:03