generate.md

Inventory of everything Rails g can do.

$ rails g -h

g and generate are interchangble

All of the Rails generators are entered as commands into the terminal and will follow this syntax:

$ rails g <name of generator> <options>

Supported Data types for migrations:

:binary
:boolean
:date
:datetime
:decimal
:float
:integer
:primary_key
:string
:text
:time
:timestamp

Generate a new Rails app w/ Postgres support

$ rails new my_app --database=postgresql

Creating a Model (name it something singular)

$ rails g model Mod name:string start_date:string
# includes the attributes: name and start date

Will create the following files:

invoke  active_record
create    db/migrate/20190618010724_create_mods.rb
create    app/models/application_record.rb
create    app/models/mod.rb

Migration file created:

class CreateMods < ActiveRecord::Migration[5.1]
  def change
    create_table :mods do |t|
      t.string :name
      t.string :start_date

      t.timestamps
    end
  end
end

Add Column to Existing Model

$ rails generate migration AddFieldToMods classroom:string

Migration file created:

class AddFieldToMods < ActiveRecord::Migration[5.1]
  def change
    add_column :mods, :classroom, :string
  end
end

The change method will allow you to:

add_column
add_index
add_timestamps
create_table
remove_timestamps
rename_column
rename_index
rename_table

Creating a Standalone Migration

$ rails g migration AddFieldToMods

Creating a Controller

_{notice the plurization}

$ rails g controller Mods show: index: create:

Will create the following files:

create  app/controllers/mods_controller.rb
       route  get 'mods/create:'
       route  get 'mods/index:'
       route  get 'mods/show:'
      invoke  erb
      create    app/views/mods
      create    app/views/mods/show:.html.erb
      create    app/views/mods/index:.html.erb
      create    app/views/mods/create:.html.erb
      invoke  rspec
      create    spec/requests/mods_request_spec.rb
      create    spec/views/mods
      create    spec/views/mods/show:.html.erb_spec.rb
      create    spec/views/mods/index:.html.erb_spec.rb
      create    spec/views/mods/create:.html.erb_spec.rb
      invoke  helper
      create    app/helpers/mods_helper.rb
      invoke    rspec
      create      spec/helpers/mods_helper_spec.rb
      invoke  assets
      invoke    coffee
      create      app/assets/javascripts/mods.coffee
      invoke    scss
      create      app/assets/stylesheets/mods.scss