I should explain what I'd like to achieve:
I'll have hundreds of numboxes like this one, in different abstractions, and I'd like to be able to pick some of them and to control them from outside (from another abstraction or from another software)
A bit like "Instant mapping" in Ableton Live. You activate this mode, you click any parameter and now you can control it.
For now, the workflow is as follows:
- Picking a numbox I want to automate from outside
- Opening the abstraction (Right click on the abstraction / Open)
- Opening the properties (Right click on the numbox / Properties)
- Copying the Receive Symbol content
- Coming back to the main patch
- Creating a Send object connected to a numbox
- Pasting the content of Send Symbol in the send object [s $0-sendnum-r]
- Finding the ID of the abstraction (going back inside the abstraction, creating a [bang] -- [f $0] -- [print] in the abstraction)
- Replacing $0 in the Send object by the ID of the abstraction [s 1003-sendnum-r]
Now I can control this numbox from the new send object, or from another software...
But this is a rather long process, not really usable in a live situation.
An alternative would be to do it the way recommended by @ddw_music, printing [symbol $0-sendnum-r] every time the parameter is changed. This involves preparing all the abstractions/parameters to make it work that way.
But I'd like to find a way that would work with any unprepared gatom.
That's how I came up with the idea of intercepting internal PD messages.