How to change source for a custom rails generator? (Thor)

Question

I\'m making a custom generator that generates a new rails app, and I do it like this

require \'thor\'
require \'rails/generators/rails/app/app_generator\'

c         


        

Answer 1

It's an old post, however, the problem remains the same, I spent time to figure that out. I let a comment here if it can help.

Rails add by default the path lib/templates so you can custom any templates by copying them in this directory.

Check out the correct directories structures https://github.com/rails/rails/tree/v6.0.1/railties/lib/rails/generators/rails

There is subtle though and is not so obvious to catch.

Take for instance the helper generator, as mentioned in the official Rails documentation, the structure is

https://github.com/rails/rails/tree/v6.0.1/railties/lib/rails/generators/rails/helper

- helper
  - templates
    - helper.rb.tt
  - helper_generator.rb 

Here, what Railties expects to find in your project:

- lib
  - templates 
    - helper
      - helper.rb

your helper.rb is a copy of helper.rb.tt

the last thing, if you plan to use it in Rails::Engine you have to tell it to load that path

# lib/blorgh/engine.rb 
module Blorgh
  class Engine < ::Rails::Engine
    isolate_namespace Blorgh
    config.generators.templates << File.expand_path('../templates', __dir__)
  end
end

Really hope that can help and save time for others.

1. https://github.com/rails/rails/blob/v6.0.1/railties/lib/rails/application/configuration.rb#L188
2. https://guides.rubyonrails.org/generators.html#customizing-your-workflow-by-changing-generators-templates
3. https://github.com/rails/rails/blob/v6.0.1/railties/CHANGELOG.md
4. https://guides.rubyonrails.org/engines.html