search for: form_rows_from_collect

I am struggling with how to add dynamically add form elements to a form based on user action. Now here is my situation: I have model Project that has_many line_items On the form to create a project I initially display form elements (some drop downs and text boxes) for adding just one line_item. There is also a button or a link on the page (not sure if this should be in the main form or