class Photo
  include DataMapper::Resource
  
  # This model uses attachmerb_fu
  has_attachment({
   :content_type  => :image,
   :path_prefix   => 'public/photos',
   :storage       => :file_system,
   :processor     => 'MiniMagick'
  })
  
  #attr_accessor :uploaded_data
  
  # Basic properties
  property :id, Integer, :serial => true
  
  # Properties needed for attachmerb_fu
  property :size, Integer, :nullable => false
  property :content_type, String, :nullable => false
  property :fliename, String, :nullable => false
  property :filename, String, :nullable => false
  property :height, Integer, :nullable => false
  property :width, Integer, :nullable => false
  property :parent_id, Integer
  property :thumbnail, String
  
  # Associations
  belongs_to :user
end

avels-macbook:flirtme Pavel$ merb
 ~ Loaded DEVELOPMENT Environment...
 ~ loading gem 'dm-types' ...
 ~ loading gem 'dm-validations' ...
 ~ loading gem 'dm-migrations' ...
 ~ loading gem 'dm-timestamps' ...
 ~ loading gem 'merb_helpers' ...
 ~ loading gem 'merb-assets' ...
 ~ loading gem 'merb-slices' ...
 ~ loading gem 'merb-parts' ...
 ~ Registered slice 'MerbAuth' located at /Library/Ruby/Gems/1.8/gems/merb-auth-0.1.0
 ~ loading gem 'merb-auth' ...
 ~ loading gem 'merb_global' ...
 ~ loading gem 'attachmerb_fu' ...
/Library/Ruby/Gems/1.8/gems/polyglot-0.2.3/lib/polyglot.rb:42:in `load': Failed to load data_mapper using extensions rb, treetop, tt (LoadError)
	from /Library/Ruby/Gems/1.8/gems/polyglot-0.2.3/lib/polyglot.rb:56:in `require'
	from /Library/Ruby/Gems/1.8/gems/attachmerb_fu-0.0.1/lib/attachmerb_fu.rb:7
	from /Library/Ruby/Gems/1.8/gems/merb-core-0.9.4/lib/merb-core/core_ext/kernel.rb:59:in `require'
	from /Library/Ruby/Gems/1.8/gems/merb-core-0.9.4/lib/merb-core/core_ext/kernel.rb:59:in `load_dependency'
	from /Library/Ruby/Gems/1.8/gems/merb-core-0.9.4/lib/merb-core/bootloader.rb:261:in `load_dependencies'
	from /Library/Ruby/Gems/1.8/gems/merb-core-0.9.4/lib/merb-core/bootloader.rb:261:in `each'
	from /Library/Ruby/Gems/1.8/gems/merb-core-0.9.4/lib/merb-core/bootloader.rb:261:in `load_dependencies'
	from /Library/Ruby/Gems/1.8/gems/merb-core-0.9.4/lib/merb-core/bootloader.rb:256:in `run'
	from /Library/Ruby/Gems/1.8/gems/merb-core-0.9.4/lib/merb-core/bootloader.rb:65:in `run'
	from /Library/Ruby/Gems/1.8/gems/merb-core-0.9.4/lib/merb-core/server.rb:51:in `start'
	from /Library/Ruby/Gems/1.8/gems/merb-core-0.9.4/lib/merb-core.rb:87:in `start'
	from /Library/Ruby/Gems/1.8/gems/merb-core-0.9.4/bin/merb:12
	from /usr/bin/merb:19:in `load'
	from /usr/bin/merb:19