how does this Ruby class method get invoked?

Question

In a screen cast on Exporting CSV from a rails app, Ryan Bates presented the following simple code.

I\'m trying to figure out how the class method Product::to_csv ac

Answer 1

This is just one of the things Rails does. Any class methods automatically become available as "collection" methods, meaning they are available to the relation objects. Scopes and class methods are interchangeable that way.