Ruby on Rails diagrams generator - this repository contains the patches that allows it to be used with rails 2.3
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RailRoad generates models and controllers diagrams in DOT language for a Rails application.

This is a patched version based on the original v0.5.0.

I (Peter Hoeg) am not trying to hijack Javier's project, but since he hasn't released any new versions since May '08, I figured I'd better put one out in order to make railroad work with rails v2.3.


Run RailRoad on the Rails application's root directory. You can redirect its output to a .dot file or pipe it to the dot or neato utilities to produce a graphic. Model diagrams are intended to be processed using dot and controller diagrams are best processed using neato.

railroad [options] command


Common options:

-b, --brief                      Generate compact diagram
                                   (no attributes nor methods)
-s, --specify file1[,fileN]      Specify given files only for the diagram
                                   (can take a glob pattern)
-e, --exclude file1[,fileN]      Exclude given files
                                   (can take a glob pattern)
-i, --inheritance                Include inheritance relations
-l, --label                      Add a label with diagram information
                                   (type, date, migration, version)
-o, --output FILE                Write diagram to file FILE
-v, --verbose                    Enable verbose output
                                   (produce messages to STDOUT)

Models diagram options:

-a, --all                        Include all models
                                   (not only ActiveRecord::Base derived)
    --hide-magic                 Hide magic field names
    --hide-types                 Hide attributes type
-j, --join                       Concentrate edges
-m, --modules                    Include modules
-p, --plugins-models             Include plugins models
-t, --transitive                 Include transitive associations
                                 (through inheritance)

Controllers diagram options:

--hide-public                Hide public methods
--hide-protected             Hide protected methods
--hide-private               Hide private methods

Other options:

-h, --help                       Show this message
    --version                    Show version and copyright


-M, --models                     Generate models diagram
-C, --controllers                Generate controllers diagram
-A, --aasm                       Generate "acts as state machine" diagram


railroad -o -M 
  Produces a models diagram to the file ''
railroad -a -i -o -M 
  Models diagram with all classes showing inheritance relations
railroad -M | dot -Tsvg > models.svg
  Model diagram in SVG format
railroad -C | neato -Tpng > controllers.png
  Controller diagram in PNG format
railroad -h
  Shows usage help

Processing DOT files

To produce a PNG image from model diagram generated by RailRoad you can issue the following command:

dot -Tpng > models.png

If you want to do the same with a controller diagram, use neato instead of dot:

neato -Tpng > controllers.png

If you want to produce SVG (vectorial, scalable, editable) files, you can do the following:

dot -Tsvg > models.svg
neato -Tsvg > controllers.svg

Important: There is a bug in Graphviz tools when generating SVG files that cause a text overflow. You can solve this problem editing (with a text editor, not a graphical SVG editor) the file and replacing around line 12 “font-size:14.00;” by “font-size:11.00;”, or by issuing the following command (see “man sed”):

sed -i 's/font-size:14.00/font-size:11.00/g' file.svg

Note: For viewing and editing SVG there is an excellent opensource tool called Inkscape (similar to Adobe Illustrator. For DOT processing you can also use Omnigraffle (on Mac OS X).

RailRoad as a rake task

(Thanks to Thomas Ritz, ,for the code.)

In your Rails application, put the following rake tasks into 'lib/task/diagrams.rake':

namespace :doc do
  namespace :diagram do
    task :models do
      sh "railroad -i -l -a -m -M | dot -Tsvg | sed 's/font-size:14.00/font-size:11.00/g' > doc/models.svg"

    task :controllers do
      sh "railroad -i -l -C | neato -Tsvg | sed 's/font-size:14.00/font-size:11.00/g' > doc/controllers.svg"

  task :diagrams => %w(diagram:models diagram:controllers)

Then, 'rake doc:diagrams' produces 'doc/models.svg' and 'doc/controllers.svg'.


RailRoad has been tested with the following Ruby and Rails versions


  • 1.8.5

  • 1.8.7


  • 1.1.6 to 1.2.3

  • 2.3.2 to 2.3.5

There are no additional requirements (nevertheless, all your Rails application requirements must be installed).

In order to view/export the DOT diagrams, you'll need the processing tools from Graphviz.

Website and Project Home


RailRoad is distributed under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

See LICENSE for details.


Copyright © 2007-2008 Javier Smaldone Copyright © 2009 Peter Hoeg

See LICENSE for details.


See AUTHORS for details.