class ActionView::TemplateRenderer

def determine_template(options)
  keys = options.has_key?(:locals) ? options[:locals].keys : []
  if options.key?(:body)
    Template::Text.new(options[:body])
  elsif options.key?(:text)
    Template::Text.new(options[:text], formats.first)
  elsif options.key?(:plain)
    Template::Text.new(options[:plain])
  elsif options.key?(:html)
    Template::HTML.new(options[:html], formats.first)
  elsif options.key?(:file)
    with_fallbacks { find_file(options[:file], nil, false, keys, @details) }
  elsif options.key?(:inline)
    handler = Template.handler_for_extension(options[:type] || "erb")
    Template.new(options[:inline], "inline template", handler, :locals => keys)
  elsif options.key?(:template)
    if options[:template].respond_to?(:render)
      options[:template]
    else
      find_template(options[:template], options[:prefixes], false, keys, @details)
    end
  else
    raise ArgumentError, "You invoked render but did not give any of :partial, :template, :inline, :file, :plain, :html, :text or :body option."
  end
end

def find_layout(layout, keys, formats)
  resolve_layout(layout, keys, formats)
end

def render(context, options)
  @view    = context
  @details = extract_details(options)
  template = determine_template(options)
  prepend_formats(template.formats)
  @lookup_context.rendered_format ||= (template.formats.first || formats.first)
  render_template(template, options[:layout], options[:locals])
end

def render_template(template, layout_name = nil, locals = nil) #:nodoc:
  view, locals = @view, locals || {}
  render_with_layout(layout_name, locals) do |layout|
    instrument(:template, :identifier => template.identifier, :layout => layout.try(:virtual_path)) do
      template.render(view, locals) { |*name| view._layout_for(*name) }
    end
  end
end

def render_with_layout(path, locals) #:nodoc:
  layout  = path && find_layout(path, locals.keys, [formats.first])
  content = yield(layout)
  if layout
    view = @view
    view.view_flow.set(:layout, content)
    layout.render(view, locals){ |*name| view._layout_for(*name) }
  else
    content
  end
end

def resolve_layout(layout, keys, formats)
  details = @details.dup
  details[:formats] = formats
  case layout
  when String
    begin
      if layout =~ /^\//
        with_fallbacks { find_template(layout, nil, false, keys, details) }
      else
        find_template(layout, nil, false, keys, details)
      end
    rescue ActionView::MissingTemplate
      all_details = @details.merge(:formats => @lookup_context.default_formats)
      raise unless template_exists?(layout, nil, false, keys, all_details)
    end
  when Proc
    resolve_layout(layout.call(formats), keys, formats)
  else
    layout
  end
end