Help with railroad

Can anyone help me install railroad gem?

What I need is a simple class diagram of my rails website. Not necessarily with railroad (if you know any other software, for mac, that works).

The website is

I couldn’t find any explanation on how to install it.

Thank you,


Have you tried running the command "gem install railroad"?
What result does that give you?

I am happy using rails erd:

If needed, not only the model diagrams, use

I did manage to install it with ‘install railroad gem’, problem is that when I run any command like ‘railroad -a -i -M | dot -Tpng > doc/models.png’ it doesn’t work, I get this:

/Users/rodrigoruiz/.rvm/gems/ruby-1.9.2-p180@rails3/gems/railroad-0.5.0/lib/railroad/app_diagram.rb:54:in `disable_stdout’: uninitialized constant AppDiagram::PLATFORM (NameError)

from /Users/rodrigoruiz/.rvm/gems/ruby-1.9.2-p180@rails3/gems/railroad-0.5.0/lib/railroad/app_diagram.rb:72:in `load_environment'

from /Users/rodrigoruiz/.rvm/gems/ruby-1.9.2-p180@rails3/gems/railroad-0.5.0/lib/railroad/app_diagram.rb:18:in `initialize'

from /Users/rodrigoruiz/.rvm/gems/ruby-1.9.2-p180@rails3/gems/railroad-0.5.0/lib/railroad/models_diagram.rb:14:in `initialize'

from /Users/rodrigoruiz/.rvm/gems/ruby-1.9.2-p180@rails3/gems/railroad-0.5.0/bin/railroad:36:in `new'

from /Users/rodrigoruiz/.rvm/gems/ruby-1.9.2-p180@rails3/gems/railroad-0.5.0/bin/railroad:36:in `<top (required)>'

from /Users/rodrigoruiz/.rvm/gems/ruby-1.9.2-p180@rails3/bin/railroad:19:in `load'

from /Users/rodrigoruiz/.rvm/gems/ruby-1.9.2-p180@rails3/bin/railroad:19:in `<main>'

Ya, actually I do need a class diagram for controllers and models.

How can I use that railroady?

do you install the graphviz? is needed for generate the diagrams, linux or mac your OS?

other mode for generate models in rails is, very simple and require too graphviz, much easer

Ya, but I need both, models and controllers diagram, and yes I did install graphviz (manually though, not through command line)

and I did manage to generate the controllers and models with their methods, but not instance variable or inheritance connections.