module Padrino::Rendering::InstanceMethods

def render(engine, data=nil, options={}, locals={}, &block)
  # If engine is a hash then render data converted to json
  content_type(:json, :charset => 'utf-8') and return engine.to_json if engine.is_a?(Hash)
  # If engine is nil, ignore engine parameter and shift up all arguments
  # render nil, "index", { :layout => true }, { :localvar => "foo" }
  engine, data, options = data, options, locals if engine.nil? && data
  # Data is a hash of options when no engine isn't explicit
  # render "index", { :layout => true }, { :localvar => "foo" }
  # Data is options, and options is locals in this case
  data, options, locals = nil, data, options if data.is_a?(Hash)
  # If data is unassigned then this is a likely a template to be resolved
  # This means that no engine was explicitly defined
  data, engine = *resolve_template(engine, options.dup) if data.nil?
  # Setup root
  root = settings.respond_to?(:root) ? settings.root : ""
  # Use @layout if it exists
  options[:layout] = @layout if options[:layout].nil?
  # Resolve layouts similar to in Rails
  if (options[:layout].nil? || options[:layout] == true) && !settings.templates.has_key?(:layout)
    layout_path, layout_engine = *resolved_layout
    options[:layout] = layout_path || false # We need to force layout false so sinatra don't try to render it
    options[:layout] = false unless layout_engine == engine # TODO allow different layout engine
    options[:layout_engine] = layout_engine || engine if options[:layout]
  elsif options[:layout].present?
    options[:layout] = settings.fetch_layout_path(options[:layout] || @layout)
  end
  # Cleanup the template
  @current_engine, engine_was = engine, @current_engine
  @_out_buf,  _buf_was = "", @_out_buf
  # Pass arguments to Sinatra render method
  super(engine, data, options.dup, locals, &block)
ensure
  @current_engine = engine_was
  @_out_buf = _buf_was
end