module DataMapper::Ext::Module

Public Class Methods

find_const(mod, const_name) click to toggle source

@api semipublic

# File lib/dm-core/support/ext/module.rb, line 5
def self.find_const(mod, const_name)
  if const_name[0..1] == '::'
    DataMapper::Ext::Object.full_const_get(const_name[2..-1])
  else
    nested_const_lookup(mod, const_name)
  end
end

Private Class Methods

nested_const_lookup(mod, const_name) click to toggle source

Doesn't do any caching since constants can change with remove_const

# File lib/dm-core/support/ext/module.rb, line 16
def self.nested_const_lookup(mod, const_name)
  unless mod.equal?(::Object)
    constants = []

    mod.name.split('::').each do |part|
      const = constants.last || ::Object
      constants << const.const_get(part)
    end

    parts = const_name.split('::')

    # from most to least specific constant, use each as a base and try
    # to find a constant with the name const_name within them
    constants.reverse_each do |const|
      # return the nested constant if available
      return const if parts.all? do |part|
        const = if RUBY_VERSION >= '1.9.0'
          const.const_defined?(part, false) ? const.const_get(part, false) : nil
        else
          const.const_defined?(part) ? const.const_get(part) : nil
        end
      end
    end
  end

  # no relative constant found, fallback to an absolute lookup and
  # use const_missing if not found
  DataMapper::Ext::Object.full_const_get(const_name)
end