DataMapper Paperclip

DM-Paperclip is a port of Thoughtbot’s Paperclip plugin to work with DataMapper 0.9. This plugin is fully compatible with the original ActiveRecord-oriented Paperclip. You could take an existing ActiveRecord database and use it with DataMapper. The module also includes updates validation handling and automatic including of the necessary ‘property’ fields into your model.

To use it within your models, you need to ensure the three database fields are included. They are {name}_file_name, {name}_content_type, and {name}_file_size. The first two are strings, the final _file_size column is an integer. So if your user model has an avatar field, then you would add avatar_file_name, avatar_content_type, and avatar_file_size.

As with the original Paperclip plugin, it allows processing of thumbnails at the time the record is saved though ImageMagick. It processes the thumbnails through the command-line applications instead of using RMagick.

See the documentation for the has_attached_file method for options.

Usage

In your model:

class User
  include DataMapper::Resource
  include Paperclip::Resource
  property :id, Integer, :serial => true
  property :username, String
  has_attached_file :avatar,
                    :styles => { :medium => "300x300>",
                                 :thumb => "100x100>" }
end

In your edit and new views:

<% form_for @user, { :action => url(:user), :multipart => true } do %>
  <%= file_field :name => 'avatar' %>
<% end %>

In your controller:

def create
  ...
  @user.avatar = params[:avatar]
end

In your show view:

<%= image_tag @user.avatar.url %>
<%= image_tag @user.avatar.url(:medium) %>
<%= image_tag @user.avatar.url(:thumb) %>