How do you get the Ruby on Rails generated id of a form element for reference in JavaScript?

Question

When using the form_for helper and a text_field call, Ruby on Rails will generate a unique id for the element that it outp

Answer 1

In Rails 4.1 I was able to get the id with this:

ActionView::Base::Tags::Base.new(
  f.object_name,
  :username,
  :this_param_is_ignored,
).send(:tag_id)

It works with nested forms (fields_for).