Bringing the Thunder with Thor & Rails Generators for

the Command Line

*Boom*

Actual Summary

• Thor (the ruby framework)

• Rails Generators

• Application Templates

What is Thor?

*In practice, not so much.

Why Thor?

• You need a CLI options parser

• It’s already installed (Rails 3)

• Useful file and directory operations

• Creating a generator

Flavors of Code Gen

~/projects/myproject(master)$

rails g model Product name:string

~/projects$

rails new myproject -m stock_project.rb

~/projects/myproject(master)$

petstore upgrade

Key Resources

• Thor::Actions - http://rdoc.info/github/wycats/thor/master/Thor/Actions.html

• Rails::Generators - http://api.rubyonrails.org/classes/Rails/Generators/Actions.html

• Writing/Overriding Generators - http://guides.rubyonrails.org/generators.html

Using Generators

rails generate model Turtle name:string

Rolling your own

rails g generator product

Product Generator

Templates

Key Points

• All public methods are invoked in order of declaration

• Private methods are available in the template

• Can have inline or external templates

• ‘working’ directory is always the root of the project

Thor::Actions

Rails::Generators::

Actions

Stupid Generator Tricks

Thor CLI Apps

• Generating code can be done without a generator

rails new MY_APP• Packaging as gem executable

• Don’t need to clutter list of generators in projects

• Example: A tool to upgrade to Rails 3

Making a Gem

http://asciicasts.com/episodes/245-new-gem-with-bundler

Gemfile & gemspec

Hello World

Showing off

Multiple Commands

Running Thor Commands

Application Templates

• Just a .rb file with thor/rails generator commands

• Used to configure new rails projects

• Can be local or remote

Sample Template

Easier kickstarting

Questions?