I'm running a Tornado server with the following class:
class SessionHandler(tornado.websocket.WebSocketHandler):
def open(self):
pass
def on_close(self):
pass
@tornado.gen.coroutine
def on_message(self,message):
#db added to the tornado application object on init
self.application.db.add("test")
x=self.application.db.get("test")
print(x)
The get function are follows (part of the db class):
@tornado.gen.coroutine
def get(self,key):
result=[]
lookup=yield self.postCol.find_one({"_id":key})
if not lookup:
return result
for id in lookup["FieldArray"]:
ob=yield self.postCol.find_one({"_id":ObjectId(id)})
result.append(ob)
return result
I won't type the add() function out.
I realized that the get() returns a Future object instead of the array. That's fine, I realize I need to change my code to x = yield self.application.db.get("test").
My question is the add() function has no explicit return value in my method?
Do I still need to yield that when I call it too I.e. yield self.application.db.add("test")?
It does currently work without my yielding, however I'm wondering if it's a mistake not to yield, because I know it does return a Future object?
If that's the case, does that mean I basically have to yield any method I call that is decorated with gen.coroutine?
Yes, you should "yield" any call to a coroutine. There are two reasons: