+module Technoweenie # :nodoc:
+ module AttachmentFu # :nodoc:
+ module Backends
+ # = CloudFiles Storage Backend
+ #
+ # Enables use of {Rackspace Cloud Files}[http://www.mosso.com/cloudfiles.jsp] as a storage mechanism
+ #
+ # Based heavily on the Amazon S3 backend.
+ #
+ # == Requirements
+ #
+ # Requires the {Cloud Files Gem}[http://www.mosso.com/cloudfiles.jsp] by Rackspace
+ #
+ # == Configuration
+ #
+ # Configuration is done via <tt>RAILS_ROOT/config/rackspace_cloudfiles.yml</tt> and is loaded according to the <tt>RAILS_ENV</tt>.
+ # The minimum connection options that you must specify are a container name, your Mosso login name and your Mosso API key.
+ # You can sign up for Cloud Files and get access keys by visiting https://www.mosso.com/buy.htm
+ #
+ # Example configuration (RAILS_ROOT/config/rackspace_cloudfiles.yml)
+ #
+ # development:
+ # container_name: appname_development
+ # username: <your key>
+ # api_key: <your key>
+ #
+ # test:
+ # container_name: appname_test
+ # username: <your key>
+ # api_key: <your key>
+ #
+ # production:
+ # container_name: appname
+ # username: <your key>
+ # apik_key: <your key>
+ #
+ # You can change the location of the config path by passing a full path to the :cloudfiles_config_path option.
+ #
+ # has_attachment :storage => :cloud_files, :cloudfiles_config_path => (RAILS_ROOT + '/config/mosso.yml')
+ #
+ # === Required configuration parameters
+ #
+ # * <tt>:username</tt> - The username for your Rackspace Cloud (Mosso) account. Provided by Rackspace.
+ # * <tt>:secret_access_key</tt> - The api key for your Rackspace Cloud account. Provided by Rackspace.
+ # * <tt>:container_name</tt> - The name of a container in your Cloud Files account.
+ #
+ # If any of these required arguments is missing, a AuthenticationException will be raised from CloudFiles::Connection.
+ #
+ # == Usage
+ #
+ # To specify Cloud Files as the storage mechanism for a model, set the acts_as_attachment <tt>:storage</tt> option to <tt>:cloud_files/tt>.
+ #
+ # class Photo < ActiveRecord::Base
+ # has_attachment :storage => :cloud_files
+ # end
+ #
+ # === Customizing the path
+ #
+ # By default, files are prefixed using a pseudo hierarchy in the form of <tt>:table_name/:id</tt>, which results
+ # in Cloud Files object names (and urls) that look like: http://:server/:container_name/:table_name/:id/:filename with :table_name
+ # representing the customizable portion of the path. You can customize this prefix using the <tt>:path_prefix</tt>
+ # option:
+ #
+ # class Photo < ActiveRecord::Base
+ # has_attachment :storage => :cloud_files, :path_prefix => 'my/custom/path'
+ # end
+ #
+ # Which would result in public URLs like <tt>http(s)://:server/:container_name/my/custom/path/:id/:filename.</tt>
+ #
+ # === Permissions
+ #
+ # File permisisons are determined by the permissions of the container. At present, the options are public (and distributed
+ # by the Limelight CDN), and private (only available to your login)
+ #
+ # === Other options
+ #
+ # Of course, all the usual configuration options apply, such as content_type and thumbnails:
+ #
+ # class Photo < ActiveRecord::Base
+ # has_attachment :storage => :cloud_files, :content_type => ['application/pdf', :image], :resize_to => 'x50'
+ # has_attachment :storage => :cloud_files, :thumbnails => { :thumb => [50, 50], :geometry => 'x50' }
+ # end
+ #
+ # === Accessing Cloud Files URLs
+ #
+ # You can get an object's public URL using the cloudfiles_url accessor. For example, assuming that for your postcard app
+ # you had a container name like 'postcard_world_development', and an attachment model called Photo:
+ #
+ # @postcard.cloudfiles_url # => http://cdn.cloudfiles.mosso.com/c45182/uploaded_files/20/london.jpg
+ #
+ # The resulting url is in the form: http://:server/:container_name/:table_name/:id/:file.
+ # The optional thumbnail argument will output the thumbnail's filename (if any).
+ #
+ # Additionally, you can get an object's base path relative to the container root using
+ # <tt>base_path</tt>:
+ #
+ # @photo.file_base_path # => uploaded_files/20
+ #
+ # And the full path (including the filename) using <tt>full_filename</tt>:
+ #
+ # @photo.full_filename # => uploaded_files/20/london.jpg
+ #
+ # Niether <tt>base_path</tt> or <tt>full_filename</tt> include the container name as part of the path.
+ # You can retrieve the container name using the <tt>container_name</tt> method.
+ module CloudFileBackend
+ class RequiredLibraryNotFoundError < StandardError; end
+ class ConfigFileNotFoundError < StandardError; end
+
+ def self.included(base) #:nodoc:
+ mattr_reader :container_name, :cloudfiles_config
+
+ begin
+ require 'cloudfiles'
+ rescue LoadError
+ raise RequiredLibraryNotFoundError.new('CloudFiles could not be loaded')
+ end
+
+ begin
+ @@cloudfiles_config_path = base.attachment_options[:cloudfiles_config_path] || (RAILS_ROOT + '/config/rackspace_cloudfiles.yml')
+ @@cloudfiles_config = @@cloudfiles_config = YAML.load(ERB.new(File.read(@@cloudfiles_config_path)).result)[RAILS_ENV].symbolize_keys
+ rescue
+ #raise ConfigFileNotFoundError.new('File %s not found' % @@cloudfiles_config_path)
+ end
+
+ @@container_name = @@cloudfiles_config[:container_name]
+ @@cf = CloudFiles::Connection.new(@@cloudfiles_config[:username], @@cloudfiles_config[:api_key])
+ @@container = @@cf.container(@@container_name)
+
+ base.before_update :rename_file
+ end
+
+ # Overwrites the base filename writer in order to store the old filename
+ def filename=(value)
+ @old_filename = filename unless filename.nil? || @old_filename
+ write_attribute :filename, sanitize_filename(value)
+ end
+
+ # The attachment ID used in the full path of a file
+ def attachment_path_id
+ ((respond_to?(:parent_id) && parent_id) || id).to_s
+ end
+
+ # The pseudo hierarchy containing the file relative to the container name
+ # Example: <tt>:table_name/:id</tt>
+ def base_path
+ File.join(attachment_options[:path_prefix], attachment_path_id)
+ end
+
+ # The full path to the file relative to the container name
+ # Example: <tt>:table_name/:id/:filename</tt>
+ def full_filename(thumbnail = nil)
+ File.join(base_path, thumbnail_name_for(thumbnail))
+ end
+
+ # All public objects are accessible via a GET request to the Cloud Files servers. You can generate a
+ # url for an object using the cloudfiles_url method.
+ #
+ # @photo.cloudfiles_url
+ #
+ # The resulting url is in the CDN URL for the object
+ #
+ # The optional thumbnail argument will output the thumbnail's filename (if any).
+ #
+ # If you are trying to get the URL for a nonpublic container, nil will be returned.
+ def cloudfiles_url(thumbnail = nil)
+ if @@container.public?
+ File.join(@@container.cdn_url, full_filename(thumbnail))
+ else
+ nil
+ end
+ end
+ alias :public_filename :cloudfiles_url
+
+ def create_temp_file
+ write_to_temp_file current_data
+ end
+
+ def current_data
+ @@container.get_object(full_filename).data
+ end
+
+ protected
+ # Called in the after_destroy callback
+ def destroy_file
+ @@container.delete_object(full_filename)
+ end
+
+ def rename_file
+ # Cloud Files doesn't rename right now, so we'll just nuke.
+ return unless @old_filename && @old_filename != filename
+
+ old_full_filename = File.join(base_path, @old_filename)
+ @@container.delete_object(old_full_filename)
+
+ @old_filename = nil
+ true
+ end
+
+ def save_to_storage
+ if save_attachment?
+ @object = @@container.create_object(full_filename)
+ @object.write((temp_path ? File.open(temp_path) : temp_data))
+ end
+
+ @old_filename = nil
+ true
+ end
+ end
+ end
+ end
+end
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