module Middleman::Util

def relative_path_from_resource(curr_resource, resource_url, relative)
  # Switch to the relative path between resource and the given resource
  # if we've been asked to.
  if relative
    # Output urls relative to the destination path, not the source path
    current_dir = Pathname('/' + curr_resource.destination_path).dirname
    relative_path = Pathname(resource_url).relative_path_from(current_dir).to_s
    # Put back the trailing slash to avoid unnecessary Apache redirects
    if resource_url.end_with?('/') && !relative_path.end_with?('/')
      relative_path << '/'
    end
    relative_path
  else
    resource_url
  end
end