render_with_spacer.ex

def render_with_spacer([], _template, _var_key, _spacer_template) do
  nil
end

def render_with_spacer([h], template, var_key, _spacer_template) do
 render template, var_key => h
end

def render_with_spacer([h|rest], template, var_key, spacer_template) do
  render template, var_key => h
  render spacer_template
  render_with_spacer(rest, template, var_key, spacer_template)
end

## Usage

render_with_spacer(@products, "product.html", :product, "spacer.html")