Question

I am wondering how best to handle JSONp objects using tornado in python,
is it best to do this:

class BaseRequest(tornado.web.RequestHandler):
      def prepare(self):
          self.result = {"success": True};
      def finish(self, chunk=None):
          self.write(self.result);
          tornado.web.RequestHandler.finish(self, chunk);

This seems like a bad idea because you’d think you could do it in on_finish(), right?

So, should I do it like above or should I write() in each of my handlers?

Answer 1

You should override the default write method and do something like this (untested):

class YourHandler(tornado.web.RequestHandler):
    ...
    def write(self, stuff):
        super(YourHandler, self).write('callback(' + json.dumps(stuff) + ')')
        self.set_header('Content-Type', 'application/javascript')

where stuff is a dictionary and callback is the jsonp callback name.