Signup Confirmation

Apart from an email regular expression, the sample application currently has no way to verify the validity of a user’s email address. Add an email address verification step to confirm a user’s signup. The new feature should create users in an inactive state, email the user an activation URI, then change the user to an active state when the URI gets hit. You might want to read up on state machines in Rails to help you with the inactive/active transition.

RSS Feed

For each user, implement an RSS feed for their microposts. Then implement an RSS feed foreach status feed, optionally restricting access to that feed using an authentication scheme. The RailsCast on generating RSS feeds will help get you started.

REST API

Many websites expose an Application Programmer Interface (API) so that third-party applications can get, post, put, and delete the application’s resources. Implement such a REST API for the sample application. The solution will involve adding respond_to blocks (Section 11.2.5) to many of the application’s controller actions; these should respond to requests for XML. Be careful about security; the API should only be accessible to authorized users.

Search

Currently, there is no way for users to find each other, apart from paging through the user index or viewing the feeds of other users. Implement a search feature to remedy this. Then add another search feature for microposts. The RailsCast on simple search forms will help get you started. If you deploy using a shared host or a dedicated server, I suggest using Thinking Sphinx (following the RailsCast on Thinking Sphinx). If you deploy on Heroku, you should follow the Heroku full text search instructions.