rails/rails — pull request #5746 by jmbejar (2012-04-04 23:54:49+00:00)
Title: Add method FormBuilder#index

This is a follow-up for the idea discussed with @josevalim in this pull request https://github.com/rails/rails/pull/1189

The idea is to add a method in the form builder object to have access to the current index, useful when using fields_for iterations if you need to know the element index.

Here there is another thread requesting this feature: https://github.com/rails/rails/issues/642