Hello,
I am trying to find the best way to hook up a python callback to write the data from my HDA menu into a json file (a dictionary that stores all the data)

At the moment I have added for each parameter the same python callback in the callback script section:

hou.phm().export_json(kwargs)

although I find this a little, well, brutal???

Would there be a better way to do this you reckon?

Any advice would be great

Many thanks

You can probably register node event callback [www.sidefx.com] for each HDA instance to handle hou.nodeEventType.ParmTupleChanged

You likely want to add it during HDA's OnLoaded callback as the node event callbacks don't persist between sessions

OH yep this works pretty well for me thanks a lot @tamte