vendor/rails/railties/lib/rails_generator/manifest.rb

   1 module Rails
   2   module Generator
   3
   4     # Manifest captures the actions a generator performs.  Instantiate
   5     # a manifest with an optional target object, hammer it with actions,
   6     # then replay or rewind on the object of your choice.
   7     #
   8     # Example:
   9     #   manifest = Manifest.new { |m|
  10     #     m.make_directory '/foo'
  11     #     m.create_file '/foo/bar.txt'
  12     #   }
  13     #   manifest.replay(creator)
  14     #   manifest.rewind(destroyer)
  15     class Manifest
  16       attr_reader :target
  17
  18       # Take a default action target.  Yield self if block given.
  19       def initialize(target = nil)
  20         @target, @actions = target, []
  21         yield self if block_given?
  22       end
  23
  24       # Record an action.
  25       def method_missing(action, *args, &block)
  26         @actions << [action, args, block]
  27       end
  28
  29       # Replay recorded actions.
  30       def replay(target = nil)
  31         send_actions(target || @target, @actions)
  32       end
  33
  34       # Rewind recorded actions.
  35       def rewind(target = nil)
  36         send_actions(target || @target, @actions.reverse)
  37       end
  38
  39       # Erase recorded actions.
  40       def erase
  41         @actions = []
  42       end
  43
  44       private
  45         def send_actions(target, actions)
  46           actions.each do |method, args, block|
  47             target.send(method, *args, &block)
  48           end
  49         end
  50     end
  51
  52   end
  53 end