Setting custom message properties in Qpid Proton using the Python binding

Question

I am trying to send a message with custom properties using the Python binding of Qpid Proton, but I can't find the right way to do it...

  message = Message()
  message.body = u"hello body"
  data = Data()
  data.put_map()
  data.enter()
  data.put_string("key")
  data.put_string("value")
  data.exit()
  message.properties = data
  messenger.put(message)
  messenger.send()

Results in...

Traceback (most recent call last):
  File "./candy_ingest.py", line 37, in <module>
    messenger.put(message)
  File "/usr/lib/python2.7/dist-packages/proton.py", line 473, in put
    message._pre_encode()
  File "/usr/lib/python2.7/dist-packages/proton.py", line 781, in _pre_encode
    props.put_object(self.properties)
  File "/usr/lib/python2.7/dist-packages/proton.py", line 2036, in put_object
    putter = self.put_mappings[obj.__class__]
KeyError: <class proton.Data at 0x2320420>

Any help welcome!

TIA, Thomas.

Answer 1

This is my code i used for connecting my RaspBerryPi to the Windows Azure Service Bus

import sys
from proton import *

#This code is for initiating the AMQP messenger
amqpmng = Messenger()
amqpmng._set_timeout(2000L) #Set timeout for sending and receiving at 2000 ms
address = "amqp://owner:<longpassword>@<namespace>.servicebus.windows.net/<queuename>" 

#This code is for creating messages
msg = Message()
msg.subject = "This is a testmessage"
msg.body = "Lorem ipsum dolor sit amet, consectetuer adipiscing elit."

#This code is for sending messages
try:
    msg.address = address
    amqpmng.put(msg)
    amqpmng.send()
except:
    e = sys.exc_info()[0]
    print e, "Waited for 2s to send messages, nothing send, connection timed out"

amqpmng.stop();

#This code is for receiving messages
amqpmng.subscribe(address)
amqpmng.start()
try:
    amqpmng.recv(1) #receive exactly 1 message (you can enter any value)
    msg = Message()
    while amqpmng.incoming > 0:
        amqpmng.get(msg)
        print(msg.body)
except:
    e = sys.exc_info()[0]
    print e, "Waited for 2s to receive messages, nothing received, connection timed out"

amqpmng.stop()

Also the message class only have two methods who takes data as parameter.

message.decode(data)
message.load(data)

I think you should use the message.load(data).

Also what i understand from the API reference is that the message.properties is using the python class dict for mapping his class properties.

Let me know if it was helpful!