if defined? ActionController

  case Rails::VERSION::STRING

    when /^(1\.|2\.0)/  # Rails 1.* - 2.0
    ActionController::Base.class_eval do
      add_method_tracer :render, 'View/#{newrelic_metric_path}/Rendering'
    end

    when /^2\.1\./  # Rails 2.1
    ActionView::PartialTemplate.class_eval do
      add_method_tracer :render, 'View/#{path_without_extension[%r{^(/.*/)?(.*)$},2]}.#{@view.template_format}.#{extension}/Partial'
    end
    # this is for template rendering, as opposed to partial rendering.
    ActionView::Template.class_eval do
      add_method_tracer :render, 'View/#{(path_without_extension || @view.controller.newrelic_metric_path)[%r{^(/.*/)?(.*)$},2]}.#{@view.template_format}.#{extension}/Rendering'
    end
#    ActionView::Template.class_eval do
#      alias_method :source_without_newrelic, :source
#      
#      def source
#        "text/html" == mime_type ? NewRelic::Agent.autoinstrument_source(source_without_newrelic) : source_without_newrelic
#      end
#    end if NewRelic::Control.instance['auto_enable_real_user_monitoring']

    when /^2\./   # Rails 2.2-2.*
    ActionView::RenderablePartial.module_eval do
      add_method_tracer :render_partial, 'View/#{path[%r{^(/.*/)?(.*)$},2]}/Partial'
    end
    ActionView::Template.class_eval do
      add_method_tracer :render, 'View/#{path[%r{^(/.*/)?(.*)$},2]}/Rendering'
    end
#    ActionView::Template.class_eval do
#      alias_method :source_without_newrelic, :source
#      
#      def source
#        "text/html" == mime_type ? NewRelic::Agent.autoinstrument_source(source_without_newrelic) : source_without_newrelic
#      end
#    end if NewRelic::Control.instance['auto_enable_real_user_monitoring']
    
  end unless NewRelic::Control.instance['disable_view_instrumentation']

  ActionController::Base.class_eval do
    include NewRelic::Agent::Instrumentation::ControllerInstrumentation

    # Compare with #alias_method_chain, which is not available in
    # Rails 1.1:
    alias_method :perform_action_without_newrelic_trace, :perform_action
    alias_method :perform_action, :perform_action_with_newrelic_trace
    private :perform_action

    def self.newrelic_write_attr(attr_name, value) # :nodoc:
      write_inheritable_attribute(attr_name, value)
    end

    def self.newrelic_read_attr(attr_name) # :nodoc:
      read_inheritable_attribute(attr_name)
    end

    # determine the path that is used in the metric name for
    # the called controller action
    def newrelic_metric_path(action_name_override = nil)
      action_part = action_name_override || action_name
      if action_name_override || self.class.action_methods.include?(action_part)
        "#{self.class.controller_path}/#{action_part}"
      else
        "#{self.class.controller_path}/(other)"
      end
    end
  end
else
  NewRelic::Agent.instance.log.debug "WARNING: ActionController instrumentation not added"
end