http://stackoverflow.com/questions/8735053/overriding-base-rails-code

overriding_engine_views.rb

app1
|- app/views/photo_contests
|                      |- index.html.erb  # => custom view template #1
|
\- Gemfile (gem 'common_engine')

app2
|- app/views/photo_contests
|                      |- index.html.erb  # => custom view template #2
|
\- Gemfile (gem 'common_engine')


common_engine
|
|- app/controllers/PhotoContentsControllers.rb
|                      |- index
|                      |- show
|                      |- vote
|
|- app/models/photo_contest.rb
|
|- app/views/photo_contents
|                      |-  index.html.erb
|                      |-  show.html.erb
|                      |-  vote.html.erb
|- config/routes.rb
|- lib/common_engine/engine.rb
|- lib/common_engine.rb
\- common_engine.gemspec