Strange escape_javascript behavior in Rails

Question

After I call the ajax method, the escape_javascript function spits out </div> </div> </div> for each item being rendered. I've checked all my closing tags, two and three times over, and I can't find an error. Is the formbuilder instantiated properly?

controller method

  def add_new_plan
    new_plan = Plan.find(params[:plan_id])
    @customer = Customer.find(params[:customer_id)

    CustomerPlan.create(...)

    # Pass a form builder to the nested form
    @f = ActionView::Helpers::FormBuilder.new(:customer, @customer, view_context, {})

    respond_to do |format|
      format.js
    end
  end

js.erb

$("#customerPlan").html(
  '<%= j( render("plan_tab1", f: @f) ) %>'
);

A mock sample of the html

<div>
  <div>
    form collection loop
      all form elements should be contained here
  </div>
  but the FormBuilder is outputting hidden fields here
</div>

the hidden fields are rendered altogether, not in their respective form iterations. (Note that the quotation marks in the inspector are not visible on the rendered page.)

Answer 1

I was updating a form within another form. Converted to the use of two separate forms, linking with a single update button via JS. The problem was that the first form <% end %> tag was still open after the ajax call.