vendor/rails/activesupport/lib/active_support/core_ext/module/introspection.rb

   1 module ActiveSupport
   2   module CoreExtensions
   3     module Module
   4       # Returns the name of the module containing this one.
   5       #
   6       #   p M::N.parent_name # => "M"
   7       def parent_name
   8         unless defined? @parent_name
   9           @parent_name = name =~ /::[^:]+\Z/ ? $`.freeze : nil
  10         end
  11         @parent_name
  12       end
  13
  14       # Returns the module which contains this one according to its name.
  15       #
  16       #   module M
  17       #     module N
  18       #     end
  19       #   end
  20       #   X = M::N
  21       #
  22       #   p M::N.parent # => M
  23       #   p X.parent    # => M
  24       #
  25       # The parent of top-level and anonymous modules is Object.
  26       #
  27       #   p M.parent          # => Object
  28       #   p Module.new.parent # => Object
  29       #
  30       def parent
  31         parent_name ? parent_name.constantize : Object
  32       end
  33
  34       # Returns all the parents of this module according to its name, ordered from
  35       # nested outwards. The receiver is not contained within the result.
  36       #
  37       #   module M
  38       #     module N
  39       #     end
  40       #   end
  41       #   X = M::N
  42       #
  43       #   p M.parents    # => [Object]
  44       #   p M::N.parents # => [M, Object]
  45       #   p X.parents    # => [M, Object]
  46       #
  47       def parents
  48         parents = []
  49         if parent_name
  50           parts = parent_name.split('::')
  51           until parts.empty?
  52             parents << (parts * '::').constantize
  53             parts.pop
  54           end
  55         end
  56         parents << Object unless parents.include? Object
  57         parents
  58       end
  59
  60       if RUBY_VERSION < '1.9'
  61         # Returns the constants that have been defined locally by this object and
  62         # not in an ancestor. This method is exact if running under Ruby 1.9. In
  63         # previous versions it may miss some constants if their definition in some
  64         # ancestor is identical to their definition in the receiver.
  65         def local_constants
  66           inherited = {}
  67
  68           ancestors.each do |anc|
  69             next if anc == self
  70             anc.constants.each { |const| inherited[const] = anc.const_get(const) }
  71           end
  72
  73           constants.select do |const|
  74             !inherited.key?(const) || inherited[const].object_id != const_get(const).object_id
  75           end
  76         end
  77       else
  78         def local_constants #:nodoc:
  79           constants(false)
  80         end
  81       end
  82
  83       # Returns the names of the constants defined locally rather than the
  84       # constants themselves. See <tt>local_constants</tt>.
  85       def local_constant_names
  86         local_constants.map { |c| c.to_s }
  87       end
  88     end
  89   end
  90 end