Tries to find a constant with the name specified in the argument string.
'Module'.constantize # => Module 'Test::Unit'.constantize # => Test::Unit
The name is assumed to be the one of a top-level constant, no matter whether it starts with “::” or not. No lexical context is taken into account:
C = 'outside' module M C = 'inside' C # => 'inside' 'C'.constantize # => 'outside', same as ::C end
NameError is raised when the name is not in CamelCase or the constant is unknown.
# File activesupport/lib/active_support/inflector/methods.rb, line 249 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