Paperclip¶ ↑

Note this is a fork of github.com/pk/sequel_paperclip which I tried to use it in a project and had to fix some of it’s issues. It tries to keep the Api pretty much the same as ActiveRecord Paperclip.

Paperclip is intended as an easy file attachment library for ActiveRecord. The intent behind it was to keep setup as easy as possible and to treat files as much like other attributes as possible. This means they aren’t saved to their final locations on disk, nor are they deleted if set to nil, until ActiveRecord::Base#save is called. It manages validations based on size and presence, if required. It can transform its assigned image into thumbnails if needed, and the prerequisites are as simple as installing ImageMagick (which, for most modern Unix-based systems, is as easy as installing the right packages). Attached files are saved to the filesystem and referenced in the browser by an easily understandable specification, which has sensible and useful defaults.

See the documentation for the has_attached_file method for options.

Usage¶ ↑

In your model:

class User < Sequel::Model
  has_attached_file :avatar, :styles => { :medium => "300x300>", :thumb => "100x100>" }

  # note class level validation declaration. This is different from Sequel validations which are object level
  validates_attachment_content_type :avatar, "image/jpg"

  def validate
    validates_presence :name
    # blah, blah
    unless avatar.valid?
      errors.add(:avatar, avatar.errors.join("\n")
    end
  end
end

In your migrations:

class AddAvatarColumnsToUser < Sequel::Migration
  def self.up
    add_column :users, :avatar_file_name,    :string
    add_column :users, :avatar_content_type, :string
    add_column :users, :avatar_file_size,    :integer
    add_column :users, :avatar_updated_at,   :datetime
  end

  def self.down
    remove_column :users, :avatar_file_name
    remove_column :users, :avatar_content_type
    remove_column :users, :avatar_file_size
    remove_column :users, :avatar_updated_at
  end
end

In your edit and new views:

<% form_for :user, @user, :url => user_path, :html => { :multipart => true } do |form| %>
  <%= form.file_field :avatar %>
<% end %>

In your controller:

def create
  @user = User.create( params[:user] )
end

In your show view:

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

Extending Interpolations¶ ↑

Simply add your own interplators like:

#config/initializers/interplations.rb
module Paperclip
  module Interpolations
    def my_value(attachment, style)
      attachment.property + '001'
    end
  end
end

# now you can have :my_value as your path parameter

Contributing¶ ↑

If you’d like to contribute a feature or bugfix, thanks! To make sure your fix/feature has a high chance of being added, please read the following guidelines:

1. Ask on the mailing list, or post a ticket in Lighthouse.

2. Make sure there are tests! I will not accept any patch that is not tested. It’s a rare time when explicit tests aren’t needed. If you have questions about writing tests for paperclip, please ask the mailing list.