How do you check if a connection is open?

[TheWicklowWolf]

I open a connection using:

from asyncua.sync import Client
conn = Client("serveraddress")
conn.connect()

before calling conn.disconnect() I would like to check if the connection is open.
Thanks

[ZuZuD]

Just as an aside, your username disturbs my productivity a lot :) When I receive a notification from TheWicklowWolf, I always think (hope?) I'll have receive some nice free beers! Are you from the county?

Thus said, you can check if the client is connected with something like this:

c = asyncua.Client(url="opc.tcp://127.0.0.1:4840")
c.uaclient.protocol == None 
Out[]: True

await c.connect()
c.uaclient.protocol
Out[]: <asyncua.client.ua_client.UASocketProtocol at 0x7fe0870ec520>

c.uaclient.protocol.state
Out[]: 'open'

await c.disconnect()
c.uaclient.protocol.state
Out[]: 'closed'

So a condition like this should do it

if c.uaclient.protocol == None or c.uaclient.protocol.state == "closed":
    print("its closed")

[TheWicklowWolf]

Who wouldn't like some Wicklow Wolf beers?

The sync library doesn't have uaclient

I think conn.tloop.is_alive() will work for me...

[ZuZuD]

Yes, you can certainly achieve the same with the async client. I can't think of any use-case that would warrant using the sync client nowadays, outside maybe of having to run python < 3.5

[oroulet]

a good reason to use the sync client is if it has to be used inside a sync application...that is why we use it..

[oroulet]

in reality we are using the sync wrapper in the sync part of an async application . Quite horrible but no time to rewrite things...

[ZuZuD]

a good reason to use the sync client is if it has to be used inside a sync application...that is why we use it..

You can wrap all your async code with asyncio.run() quite easily these days.

[dmitry-av]

Sync client actually has uaclient, it can be accessed via
client.aio_obj.uaclient.protocol.state
tloop.is_alive() returns True even if socket connection was closed for some reason