Ok, thanks.
Now things are more clear in my mind.
I'll try and let you know if I succeed. Otherwise I would bother you
again :)
Regards,
Giorgio
On 24/01/2012 13:49, Murphy McCauley wrote:
The minimum to get up and going should be something like this:
1) In your component's install function:
from nox.coreapps.messenger.pymsgevent import JSONMsg_event
JSONMsg_event.register_event_converter(self.ctxt)
self.register_handler(JSONMsg_event.static_get_name(), myHandler)
2) Implement a handler:
def myHandler (e):
import json
print json.loads(e.jsonstring)
e.reply(json.dumps({msg:Hello world}))
3) Include jsonmessenger on the commandline or as a dependency
That may not be exactly correct -- it's adapted from a quick writeup I
did in December about using the new Python support for the regular
messenger (as opposed to the JSON messenger), which has not yet been
pushed to the repository. For reference, that post was:
http://noxrepo.org/pipermail/nox-dev/2011-December/008382.html
(If using the new version of messenger that I linked to in that post,
you remove the register_event_converter() call from step 1 and include
pyjsonmessenger instead of jsonmessenger in step 3.)
Invoking the jsonmessenger component (on the commandline or by
including it as a dependency in your app's meta.json) will create the
server socket for you.
You absolutely do not have to use the messenger.py class. I'm
removing it from that directory, because all it ever does is confuse
people -- it really doesn't belong there. messenger.py is a library
for writing JSON messenger *clients* (external programs) in Python.
That may be useful to you, but you don't need it for the NOX side of
things.
Hope that helps.
-- Murphy
On Jan 24, 2012, at 4:12 AM, Giorgio Mazza wrote:
Thank you.
I try to sum up the operations I need to perform, to see if I
understood correctly.
Basically in my external application I have to set up a socket that
sends json messages and this would be quite simple.
In my nox component, instead, I have to import the JSONMsg_event
and, within the install() instruction, to handle it with my
specific method, that, in my case, would only save these json
messages into a dictionary, for using them later, according to some
conditions.
Is that correct?
A couple of things that I didn't understand:
- I assume I also have to set up a server socket in my nox component,
in order to receive json messages and handle JSONMsg_events. So, I
think this socket has to be already up and running when I handle the
event. So, when do I have to create it and how? Do I have to use
messenger.py channel class?
- Second question, probably related to the first. I think to be
pretty confused about jsonmessenger: what are the jsonmessenger files
I could look into in order to understand fields and methods that I
would need to use? Are the jsonmessenger.cc and jsonmessenger.hh in
nox/src/nox/coreapps/messenger? And, if it is the case, how can I
integrate them into a python component?
Thanks again,
Giorgio
On 24/01/2012 12:28, Kyriakos Zarifis wrote:
Hi Giorgio,
yes, I think using jsonmessenger would be the best approach for this.
you need to implement a send/receive interface on the external
application and in your nox component. For the external application,
it's pretty straightforward - Connect to the jsonmessenger socket
and send json strings. In your nox application you need to register
for JSON messages, and handle them appropriately.
The wiki explains the communication in a few steps (specifically for
the GUI-NOX, but it will be similar and simpler for any external
app) here
http://noxrepo.org/noxwiki/index.php/NOX_GUI#Connecting_a_subview_to_a_NOX_component:
If you want to see a full example, the GUI
http://tinyurl.com/6p2yl5o and the monitoring
http://tinyurl.com/6nv83a3 component in destiny could be a place
to look. I'm afraid it's much more complex than what you need, but
the bits you need are in there if you dig in the code a bit.
On Tue, Jan 24, 2012 at 2:16 AM, Giorgio Mazza
giorgio.mazza...@gmail.com mailto:giorgio.mazza...@gmail.com wrote:
Hi all!
I have written a simple component in python that works fine.
Now I would to improve it, making it to install flow entries
depending on parameters received from an external application.
In particular I want to pass those parameters via json messages
to my component, which, in my thougths, has to open a
permanent socket listening for them, save those parameters in
a dictionary and, as a consequence, decide the desired switch
behaviour (whether install or not a flow entry for the received
parameters).
In previous threads I found that I have to use jsonmessenger
(even in python?) or to have a look to discovery.py, but I am
not sure to have understood what I have to do and where in order
to realize such a behaviour.
Could anyone, please, help me?
Thank you in
