determine_template

# File actionview/lib/action_view/renderer/template_renderer.rb, line 16
      def determine_template(options)
        keys = options.has_key?(:locals) ? options[:locals].keys : []

        if options.key?(:body)
          Template::Text.new(options[:body])
        elsif options.key?(:plain)
          Template::Text.new(options[:plain])
        elsif options.key?(:html)
          Template::HTML.new(options[:html], formats.first)
        elsif options.key?(:file)
          if File.exist?(options[:file])
            Template::RawFile.new(options[:file])
          else
            if Pathname.new(options[:file]).absolute?
              raise ArgumentError, "File #{options[:file]} does not exist"
            else
              raise ArgumentError, "`render file:` should be given the absolute path to a file. '#{options[:file]}' was given instead"
            end
          end
        elsif options.key?(:inline)
          handler = Template.handler_for_extension(options[:type] || "erb")
          format = if handler.respond_to?(:default_format)
            handler.default_format
          else
            @lookup_context.formats.first
          end
          Template::Inline.new(options[:inline], "inline template", handler, locals: keys, format: format)
        elsif options.key?(:renderable)
          Template::Renderable.new(options[:renderable])
        elsif options.key?(:template)
          if options[:template].respond_to?(:render)
            options[:template]
          else
            @lookup_context.find_template(options[:template], options[:prefixes], false, keys, @details)
          end
        else
          raise ArgumentError, "You invoked render but did not give any of :body, :file, :html, :inline, :partial, :plain, :renderable, or :template option."
        end
      end