updated top the the new version of attachment_fu plugin to work out some
[selectricity-live] / vendor / plugins / attachment_fu / lib / technoweenie / attachment_fu / backends / cloud_file_backend.rb
diff --git a/vendor/plugins/attachment_fu/lib/technoweenie/attachment_fu/backends/cloud_file_backend.rb b/vendor/plugins/attachment_fu/lib/technoweenie/attachment_fu/backends/cloud_file_backend.rb
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+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

Benjamin Mako Hill || Want to submit a patch?