projects.mako.cc - selectricity/blob - vendor/plugins/attachment_fu/lib/technoweenie/attachment_fu/backends/file_system_backend.rb

   1 require 'ftools'
   2 module Technoweenie # :nodoc:
   3   module AttachmentFu # :nodoc:
   4     module Backends
   5       # Methods for file system backed attachments
   6       module FileSystemBackend
   7         def self.included(base) #:nodoc:
   8           base.before_update :rename_file
   9         end
  10
  11         # Gets the full path to the filename in this format:
  12         #
  13         #   # This assumes a model name like MyModel
  14         #   # public/#{table_name} is the default filesystem path
  15         #   RAILS_ROOT/public/my_models/5/blah.jpg
  16         #
  17         # Overwrite this method in your model to customize the filename.
  18         # The optional thumbnail argument will output the thumbnail's filename.
  19         def full_filename(thumbnail = nil)
  20           file_system_path = (thumbnail ? thumbnail_class : self).attachment_options[:path_prefix].to_s
  21           File.join(RAILS_ROOT, file_system_path, *partitioned_path(thumbnail_name_for(thumbnail)))
  22         end
  23
  24         # Used as the base path that #public_filename strips off full_filename to create the public path
  25         def base_path
  26           @base_path ||= File.join(RAILS_ROOT, 'public')
  27         end
  28
  29         # The attachment ID used in the full path of a file
  30         def attachment_path_id
  31           ((respond_to?(:parent_id) && parent_id) || id).to_i
  32         end
  33
  34         # overrwrite this to do your own app-specific partitioning.
  35         # you can thank Jamis Buck for this: http://www.37signals.com/svn/archives2/id_partitioning.php
  36         def partitioned_path(*args)
  37           ("%08d" % attachment_path_id).scan(/..../) + args
  38         end
  39
  40         # Gets the public path to the file
  41         # The optional thumbnail argument will output the thumbnail's filename.
  42         def public_filename(thumbnail = nil)
  43           full_filename(thumbnail).gsub %r(^#{Regexp.escape(base_path)}), ''
  44         end
  45
  46         def filename=(value)
  47           @old_filename = full_filename unless filename.nil? || @old_filename
  48           write_attribute :filename, sanitize_filename(value)
  49         end
  50
  51         # Creates a temp file from the currently saved file.
  52         def create_temp_file
  53           copy_to_temp_file full_filename
  54         end
  55
  56         protected
  57           # Destroys the file.  Called in the after_destroy callback
  58           def destroy_file
  59             FileUtils.rm full_filename
  60             # remove directory also if it is now empty
  61             Dir.rmdir(File.dirname(full_filename)) if (Dir.entries(File.dirname(full_filename))-['.','..']).empty?
  62           rescue
  63             logger.info "Exception destroying  #{full_filename.inspect}: [#{$!.class.name}] #{$1.to_s}"
  64             logger.warn $!.backtrace.collect { |b| " > #{b}" }.join("\n")
  65           end
  66
  67           # Renames the given file before saving
  68           def rename_file
  69             return unless @old_filename && @old_filename != full_filename
  70             if save_attachment? && File.exists?(@old_filename)
  71               FileUtils.rm @old_filename
  72             elsif File.exists?(@old_filename)
  73               FileUtils.mv @old_filename, full_filename
  74             end
  75             @old_filename =  nil
  76             true
  77           end
  78
  79           # Saves the file to the file system
  80           def save_to_storage
  81             if save_attachment?
  82               # TODO: This overwrites the file if it exists, maybe have an allow_overwrite option?
  83               FileUtils.mkdir_p(File.dirname(full_filename))
  84               File.cp(temp_path, full_filename)
  85               File.chmod(attachment_options[:chmod] || 0644, full_filename)
  86             end
  87             @old_filename = nil
  88             true
  89           end
  90
  91           def current_data
  92             File.file?(full_filename) ? File.read(full_filename) : nil
  93           end
  94       end
  95     end
  96   end
  97 end