how to get all the parameters id of all parameters of a track (even those nested in a rack, in a rack, in a rack etc..)

I know at least one person who has done this sort of thing. Here's a start for how you get get at this.

For your goal you'd need to modify it so that it includes the Chain ids when it's building the list. And once you have the full list of device/chain ids you'll need to type-check them so that you can get mixer_device parameters in the Chains.

//// Trivial example usage... 
function bang() {
	var api = new LiveAPI(null, "live_set tracks 1")

	var device_ids = get_all_child_device_ids(api)

	post("device_ids","\n")
	for (var i = 0; i < device_ids.length; i+=2) {
		api.id = device_ids[i+1]
		post("  ", api.get("name"), "id", api.id, "\n")
	}
}


/*
get_all_child_device_ids

Returns a list of all child ids of api_obj (which could be a Track or Chain).  Called recursively into device Racks/Chains.  

The returned ids list is in order such that earlier ids in Chains always come before ids downstream of those chains.

EXAMPLE: 

var child_ids_list = get_all_child_device_ids( my_track_api_obj )

*/
function get_all_child_device_ids(api_obj, matching_ids_list) {
	// Concat matching ids in recursive usage (for RackDevice and their Chains)
	var matching_ids = (matching_ids_list && matching_ids_list.length) ? matching_ids_list : []
	var original_id = api_obj.id

	// 2023-06-05 : Put in a try/catch while trying to debug why this wasn't working with nested Drum Racks.  The issue was that I didn't know "DrumChain" existed as a type.  Rather than explicitly testing against three types (Track, Chain, DrumChain), it seems easier to just try to get "devices" children, and if it fails we know we passed something bogus.  With the catch{} we will now print the informative error in that case, instead.

	try {
		var devices = api_obj.get("devices") // This should fail and throw error if type is not correct
		// post("devices", devices, "\n")

		for (var i = 0; i < devices.length; i+=2) {
			api_obj.id = parseInt(devices[i+1])

			// Include the device.
			matching_ids[matching_ids.length] = "id"
			matching_ids[matching_ids.length] = parseInt(devices[i+1])
			
			if (api_obj.type == "RackDevice") {
				// If it's a RackDevice, call recursively to look in its chains.
				var chains_ids = api_obj.get("chains")
				// post("chains_ids", chains_ids, "\n")
				if ( chains_ids == "<empty>" || ! chains_ids ) { continue } // Drum Racks can exist with no chains.
				for (var n = 0; n < chains_ids.length; n+=2) {
					// post(" test id:", parseInt(chains_ids[n+1]), "\n")
					var id = parseInt(chains_ids[n+1])
					if ( id ) { // id can be 'nan'.  This should prevent calling below that.
						api_obj.id = id
						matching_ids = get_all_child_device_ids(api_obj, matching_ids)
					}
				}
			}
		}
	} catch (err) {
		error(String(err), "get_all_child_device_ids() requires LiveAPI object with children devices (Track/Chain/DrumChain).  api_obj id was: " + api_obj.id, "\n")
	} finally {
		api_obj.id = original_id	// restore initial api_obj selection
		return matching_ids
	}
};