A great use for Thor is creating custom generators. CombiningThor::Group,Thor::Actions and ERB templates makes this very easy. Here is an example:

classNewgem <Thor::GroupincludeThor::Actions# Define arguments and optionsargument:nameclass_option:test_framework,:default=>:test_unitdefself.source_rootFile.dirname(__FILE__)enddefcreate_lib_filetemplate('templates/newgem.tt',"#{name}/lib/#{name}.rb")enddefcreate_test_filetest=options[:test_framework] =="rspec" ?:spec ::testcreate_file"#{name}/#{test}/#{name}_#{test}.rb"enddefcopy_licenceifyes?("Use MIT license?")# Make a copy of the MITLICENSE file at the source rootcopy_file"MITLICENSE","#{name}/MITLICENSE"elsesay"Shame on you…",:redendendend

Doing athor -T will show how to run our generator. It should read:thor newgem NAME. This shows that we have to supply a NAMEargument for our generator to run.

Thecreate_lib_file uses an ERB template. This is what it looks like:

class <%=name.capitalize %>end

The arguments that you set in your generator will automatically be passed inwhentemplate gets called. Be sure to read thedocumentation for more options.

Running the generator withthor newgem devise will create two files: "devise/lib/devise.rb", and "devise/test/devise_test.rb". The user will then be asked (via a prompt by theyes? method) whether or not they would like to copy the MIT License. If you want to change the test framework, you can add the option:thor newgem devise --test-framework=rspec.

This will generate two files: "devise/lib/devise.rb" and "devise/spec/devise_spec.rb".