Show the differnce between versions with rails?

How to show the differences between versions? Like in SO once we开发者_开发技巧 creates a question after that if any modification will apply to that question it shows the changes. It shows whatever changes applied to that question when we clicks on link. Like new tags applied or question modification etc ..

Any gems or plugins?

Any Idea? Something like this ..

If you are looking for versioning your model and tracking diffs, vestal_versions is a very good option. It tracks model changes through diffs. And has a nice clean API, which will make traversing through diffs a walk in the park.

It is also incredible easy to write your own versioning system for ActiveRecord. I wrote one here.

I would use paper_trail

You can find a great screencast about this here: http://railscasts.com/episodes/255-undo-with-paper-trail

You can try this gem, it should also be compatible with Rails 3:

https://github.com/technoweenie/acts_as_versioned