lib/active_support/inflector/methods.rb
module ActiveSupport
module Inflector
extend self
def constantize(camel_cased_word)
names = camel_cased_word.split('::')
# Trigger a built-in NameError exception including the ill-formed constant in the message.
Object.const_get(camel_cased_word) if names.empty?
# Remove the first blank element in case of '::ClassName' notation.
names.shift if names.size > 1 && names.first.empty?
names.inject(Object) do |constant, name|
if constant == Object
constant.const_get(name)
else
candidate = constant.const_get(name)
next candidate if constant.const_defined?(name, false)
next candidate unless Object.const_defined?(name)
# Go down the ancestors to check if it is owned directly. The check
# stops when we reach Object or the end of ancestors tree.
constant = constant.ancestors.inject do |const, ancestor|
break const if ancestor == Object
break ancestor if ancestor.const_defined?(name, false)
const
end
# owner is in Object, so raise
constant.const_get(name, false)
end
end
end
end
end