String to Class

ruby-talk
1

Is it possible to convert a String into a Class id?

Something like 'Array'.to_class.new

2

Roberto Eduardo Decurnex Gorosito wrote:

Is it possible to convert a String into a Class id?

Something like 'Array'.to_class.new

Object.const_get("Array").new

Wolfgang Nádasi-Donner

···

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3

Or more generally,
   # from Jim Weirich (based on email correspondence)
   def constantize(camel_cased_word)
     camel_cased_word.
       sub(/^::/,'').
       split("::").
       inject(Object) { |scope, name| scope.const_get(name) }
   end

Also, you can see how ActiveSupport does it for Rails:

# File vendor/rails/activesupport/lib/active_support/inflector.rb, line 245
245: def constantize(camel_cased_word)
246: unless /\A(?:::)?([A-Z]\w*(?:::[A-Z]\w*)*)\z/ =~ camel_cased_word
247: raise NameError, "#{camel_cased_word.inspect} is not a valid constant name!"
248: end
249:
250: Object.module_eval("::#{$1}", __FILE__, __LINE__)
251: end

-Rob

Rob Biedenharn http://agileconsultingllc.com
Rob@AgileConsultingLLC.com

···

On Feb 4, 2008, at 2:30 PM, Wolfgang Nádasi-Donner wrote:

Roberto Eduardo Decurnex Gorosito wrote:

Is it possible to convert a String into a Class id?

Something like 'Array'.to_class.new

Object.const_get("Array").new

Wolfgang Nádasi-Donner