Question

I have the name of a class and I want to create an instance of that class so that I can loop through each rails attribute that is present in the schema of that class.

How would I go about doing that?

1. I have the name as a string of the class I want to check
2. I guess I need to instantiate a class instance so that I can
3. Loop through it’s attributes and print them.

Answer 1

In rails you can just do:

clazz = 'ExampleClass'.constantize

In pure ruby:

clazz = Object.const_get('ExampleClass')

with modules:

module Foo
  class Bar
  end
end

you would use

> clazz = 'Foo::Bar'.split('::').inject(Object) {|o,c| o.const_get c}
  => Foo::Bar 
> clazz.new
  => #<Foo::Bar:0x0000010110a4f8>