This is a Ruby class for converting unified diff, like the one you get with ‘svn diff’, to HTML like in changeset viewer of a tool like Trac, GitHub or Codenotifier, e.g. codenotifier.com/projects/49/commits/47#F0.

It’s based on code from gurge.com/blog/2006/10/03/subversion-diff-viewer-cgi-in-ruby (thanks Adam Doppelt!), adopted lightly to support multifile diffs and to have more familiar output. It definitely have things to improve, so contribution/patches are very welcome.

• install the gem:

  gem install artemv-diff_to_html --source=http://gems.github.com

• go to gem’s ‘examples’ dir (it’s …/ruby/lib/ruby/gems/1.8/gems/artemv-diff_to_html-x.x.x/examples/) and run ‘ruby test.rb >out.html’ - this will get diff from sample ‘svn diff’ and generate out.html. Resulting html is linked to diff.css in ‘examples’ directory - you’ll need to copy it to your project’s dir to use it.

• To use in Rails project:

  require 'diff_to_html'
  diff = `cat #{File.join(File.dirname(__FILE__), 'diff.svn')}`
  converter = SvnDiffToHtml.new #there's also GitDiffToHtml
  puts converter.composite_to_html(diff)
  

• to use in any Ruby program:

  require 'rubygems'
  require 'diff_to_html'
  ...

diff_to_html is released under the MIT license.

Authors

Artem Vasiliev

Original code

Adam Doppelt, gurge.com/blog/2006/10/03/subversion-diff-viewer-cgi-in-ruby