If you have watched the episode about mongoid from railscast, ryanb removed the default type String for field, like
class Article
field :name, :type => String
field :content, :type => String
end
can be written as
class Article
field :name
field :content
end
but it is not valid from mongoid.2.0.0.rc.1 again, the default type of field is changed from String to Object, that means we should explicitly set the type for each field.
