"Invalid Params" Error when connecting to Qlik Sense Engine API using Python

[sanchayan]

Hi All,

I am able to connect to Qlik Sense Desktop Engine API using this below python script :

from websocket import create_connection

import json

ws = create_connection("ws://localhost:4848/app/")

data_1=json.dumps({

'jsonrpc': '2.0',

'id': 0,

'method': 'OpenDoc',

'handle': -1,

'params': ['C:\\Users\\sbhowmik\\Documents\\Qlik\\Sense\\Apps\\Converter.qvf']

})

data_2=json.dumps({

'jsonrpc': '2.0',

'id': 5,

'method': 'GetConnections',

'handle': 1,

'params': []

})

print("Sending request 1...")

ws.send(data_1)

print("Sent")

print("Receiving...")

result_1 = ws.recv()

print("Received '%s'" % result_1)

print("Sending request 2...")

ws.send(data_2)

print("Sent")

print("Receiving...")

result_2 = ws.recv()

print("Received '%s'" % result_2)

ws.close()

The message I get in return from engine is as below :

{"jsonrpc":"2.0","method":"OnConnected","params":{"qSessionState":"SESSION_CREATED"}}

{"jsonrpc":"2.0","id":5,"error":{"code":-32602,"parameter":"Invalid handle","message":"Invalid Params"}}

>> Problem Statement : But, the app Test.qvf does not open up AND also, I do not get any QReturn message from the Engine API . I dont understand that why even this Invalid Param message is showing up every time. I maybe doing something wrong here. Please help.

[jonathandienst]

I have not interacted with the API in Python but in javascript, I have to serialize the JSON before sending it:

ws.send(JSON.stringify(msg));

"msg" is a JSON object. I expect the same applies to Python (the websocket does not care about the language of the caller).

[sanchayan]

I too am not much aware about python but I think JSON.dumps(msg) does the same thing as JSON.stringify(msg).

Regards,

Sanchayan Bhowmik