Goals

• Learn to treat files as an ActiveRecord attribute type, like :string or :integer

Research

• Look at the README for the paperclip gem
• Look at the README for the carrierwave gem
• Understand some advantages of CarrierWave over Paperclip
• Read about Common mistakes when storing file uploads with Rails

Exercise

In MovieDB, allow movie authors to upload a movie poster using the carrierwave gem:

• The poster should be uploaded in the form where we can also fill in title, year, etc.
• On the movie show view, render a poster version that is 400 pixel wide, with a height that respects the aspect ratio of the original image
• On the movie index view, render a poster version that is 100 pixel wide and cropped to 100 pixel height, regardless of the original aspect ratio
• On the movie show view, offer a link to download the original poster image file.
• When editing a movie, offer controls to delete or replace the poster image file.

You do not need to treat movie posters as confidential, so it's not important if an unauthorized user can see a poster.

Make sure to add integration tests for adding, changing and deleting a poster image.