I use attachment_fu for uploading avatars.
I only want to save the attachment, if the height and the width of the
image are smaller than 100px.(the system should not resize it) If the
attachment is larger I want to show a error message.
Here is my the model.
class Avatar < ActiveRecord::Base
has_attachment :content_type => :image,
:storage => :file_system,
:max_size => 300.kilobytes
thanks for your help.