Hub Connection is not invoking method to server using SignalR in Python

Question

I'm trying to establish a hub connection and negotiate through an API provided by a stock exchange company. This is the piece of code developed using the Signalr_aio in Python.

from signalr_aio import Connection
import asyncio
from requests import Session

async def pushMessage(**msg):
    print(msg)
    if 'R' in msg and type(msg['R']) is not bool:
        token = msg['R']
        sessionRealtime.headers.update({'Authorization': 'Bearer {}'.format(token)})

server_url = 'https://edbi.ephoenix.ir/realtime'
sessionRealtime = Session()
connection = Connection(server_url, session=sessionRealtime)
connection.received += pushMessage
hub = connection.register_hub('omsclienttokenhub')
hub.server.invoke('GetAPIToken', 'xxxxxxxxx', 'yyyyyyyyyy')
hub = connection.register_hub('omsclienthub')
connection.start()

I tried the 'GetTime' method and it did successfully returned the time,

hub.server.invoke('GetTime')

{'R': '00:19:10', 'I': '2'}

However, I get an error when I invoke the 'GetInstrumentList' method,

hub.server.invoke('GetInstrumentList')

{'R': {'ex': {'i': None, 'm': 'Object reference not set to an instance of an object.'}}, 'I': '1'}

I guess that there is a problem in updating the header of the request? Or should I transport the token as a querystring in a modified URL?!

I'd transport the token as a query string in a modified url. — gnahum, Apr 15 '20 at 04:10
Tkanks @gnahum. Do you have any idea what the string format should look like? — Mohammad Namakshenas, Apr 15 '20 at 04:48
something along the lines of "https://edbi.ephoneix.ir/realtime?token=abc1234" — gnahum, Apr 15 '20 at 05:55
Tkanks @gnahum. How do you do that with requests and session? — Mohammad Namakshenas, Apr 16 '20 at 15:23
with requests you can do something similar to this question: https://stackoverflow.com/questions/42601812/python-requests-url-base-in-session — gnahum, Apr 16 '20 at 17:09
instead of sessionRealtime.headers.update({'Authorization': 'Bearer {}'.format(token)}) try this sessionRealtime.auth = ('token', token) — Nandan Rana, Apr 16 '20 at 19:27
Dear @gnahum. Unfortunately, it's not working. I tested both this option and other options of **requests** methods. — Mohammad Namakshenas, Apr 16 '20 at 19:27
Thanks @NandanRana. This is a SignalR Hub connection. I passed user and pass through the following line: hub.server.invoke('GetAPIToken', 'user', 'pass') — Mohammad Namakshenas, Apr 16 '20 at 19:30
Dear @NandanRana. I tested sessionRealtime.auth = ('token', token). Unfortunately, it is either not working. — Mohammad Namakshenas, Apr 16 '20 at 19:34
Did you went through https://edbi.ephoenix.ir/realtime integration doc. How they are expecting token in body or in header of the request? instead of token are they expecting any other value as parameter name ? — Nandan Rana, Apr 16 '20 at 19:40
The docs say that the Token should be sent in a QueryString. — Mohammad Namakshenas, Apr 16 '20 at 19:41

Nandan Rana · Answer 1 · 2020-04-16T20:26:37.643

1

Try out below code

from requests import Session
from signalr import Connection
import asyncio

server_url = 'https://edbi.ephoenix.ir/realtime'

async def pushMessage(**msg):
    print(msg)
    if 'R' in msg and type(msg['R']) is not bool:
        token = msg['R']
        global server_url
        server_url = 'https://edbi.ephoenix.ir/realtime' +  "?Token={}".format(token)

with Session() as session:
    #create a connection  
    connection = Connection(server_url, session)
    connection.received += pushMessage
    hub = connection.register_hub('omsclienttokenhub')
    hub.server.invoke('GetAPIToken', 'xxxxxxxxx', 'yyyyyyyyyy')
    hub = connection.register_hub('omsclienthub')
    connection.start()

I had taken some reference from this link

edited Apr 16 '20 at 20:26

answered Apr 16 '20 at 20:04

Nandan Rana

539
3
12

I cannot put connection = Connection(server_url + "?Token={}".format(token), session) at that line since the token is released after registering the connection connection.register_hub('omsclienttokenhub'). – Mohammad Namakshenas Apr 16 '20 at 20:09
Another issue is that the token is retrieved in a serialized fashion through an **async** procedure. That's why I defined the function **async def pushMessage(**msg)**. – Mohammad Namakshenas Apr 16 '20 at 20:12
Yes. {'R': {'ex': {'i': None, 'm': 'Object reference not set to an instance of an object.'}}, 'I': '1'} – Mohammad Namakshenas Apr 16 '20 at 20:29

Hub Connection is not invoking method to server using SignalR in Python

1 Answers1