Ctags allows you to follow tags (of functions, variables, macros, whatever) to their definitions. If you do your Rails development in an editor that supports Ctags you might have been manually setting the TAGS-file up in your projects. To create a TAGS-file in my Rails projects, I always created a rake task.
Finally, I got tired of this and decided to write up a Rails plugin to do it. The result is Mactag. Mactag gives you a DSL to create a TAGS-file for your Rails projects.
An example configuration (config/mactag.rb) might look like this:
Mactag::Table.generate do
app "app/**/*.rb", "lib/*.rb"
plugins "thinking-sphinx", "whenever"
gems "paperclip", "authlogic"
gem "formtastic", :version => "0.9.7"
rails :except => :actionmailer, :version => "2.3.5"
end
When this is set up you just run the builtin rake-task and the TAGS-file will be created for you.
$ rake mactag
See README at Github for a brief howto. And the documentation for detailed information.