# File lib/sinatra/tilt.rb, line 683
683:     def evaluate(scope=nil, locals={}, &block)
684:       instance = @engine.new
685: 
686:       # copy instance variables from scope to the view
687:       scope.instance_variables.each do |name|
688:         instance.instance_variable_set(name, scope.instance_variable_get(name))
689:       end
690: 
691:       # locals get added to the view's context
692:       locals.each do |local, value|
693:         instance[local] = value
694:       end
695: 
696:       # if we're passed a block it's a subview. Sticking it in yield
697:       # lets us use {{yield}} in layout.html to render the actual page.
698:       instance[:yield] = block.call if block
699: 
700:       instance.template = data unless instance.compiled?
701: 
702:       instance.to_html
703:     end

     # File lib/sinatra/tilt.rb, line 668
668:     def initialize_engine
669:       return if defined? ::Mustache
670:       require_template_library 'mustache'
671:     end

     # File lib/sinatra/tilt.rb, line 673
673:     def prepare
674:       Mustache.view_namespace = options[:namespace]
675:       Mustache.view_path = options[:view_path] || options[:mustaches]
676:       @engine = options[:view] || Mustache.view_class(name)
677:       options.each do |key, value|
678:         next if %w[view view_path namespace mustaches].include?(key.to_s)
679:         @engine.send("#{key}=", value) if @engine.respond_to? "#{key}="
680:       end
681:     end