Are nested subflows a problem?

After some feedback from other forum members, I am attempting to re-develop a flow that controls a multi-channel device. As I was working through this it seems that having a subflow within a subflow will be required. Is this frowned upon? So far my example works as expected. I have noticed though that once there are nested subflows, debug messages cease to function within the main and nested subflow for some reason. This is not a huge problem, just an observation. Here is my example flow. Any feedback is greatly appreciated. Thanks!

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msg;","outputs":1,"noerr":0,"x":723.8332061767578,"y":237.9961452484131,"wires":[[]]},{"id":"761558c9.42f968","type":"switch","z":"92d4aa52.741878","name":"","property":"param","propertyType":"msg","rules":[{"t":"eq","v":"temperature","vt":"str"},{"t":"eq","v":"power","vt":"str"}],"checkall":"true","repair":false,"outputs":2,"x":200,"y":259.6627712249756,"wires":[["a9a0e6cc.9f3828"],["8f55d485.c45fa8"]]},{"id":"8f55d485.c45fa8","type":"function","z":"92d4aa52.741878","name":"doubleVal","func":"power = msg.payload\npower = power*2\nflow.set(\"chXPower\", power)\nreturn msg;","outputs":1,"noerr":0,"x":412.8528480529785,"y":305,"wires":[["ce85646f.bca3d8"]]},{"id":"ce85646f.bca3d8","type":"function","z":"92d4aa52.741878","name":"set topic","func":"channel = flow.get(\"chNum\")\nmsg.payload = flow.get(\"chXPower\")\npower = msg.payload\nmsg.topic = channel + \"/power\"\nreturn 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msg;","outputs":1,"noerr":0,"x":414.87232398986816,"y":241.6744508743286,"wires":[["fda4ac56.e742a","4b70be2f.ae9de"]]},{"id":"4b70be2f.ae9de","type":"debug","z":"e89e1a81.ab1328","name":"","active":false,"tosidebar":true,"console":false,"tostatus":false,"complete":"false","x":531.7434101104736,"y":364.17062759399414,"wires":[]},{"id":"57c6f97a.e64b58","type":"debug","z":"e89e1a81.ab1328","name":"","active":false,"tosidebar":true,"console":false,"tostatus":false,"complete":"true","targetType":"full","x":341.73558235168457,"y":389.17834854125977,"wires":[]},{"id":"7a1cdecd.db12c","type":"subflow:92d4aa52.741878","z":"e89e1a81.ab1328","name":"ch1","env":[],"x":891.8828868865967,"y":202.85544967651367,"wires":[[]]},{"id":"82e3255e.ef4508","type":"subflow:92d4aa52.741878","z":"e89e1a81.ab1328","name":"ch2","env":[],"x":893.0195140838623,"y":250.00389671325684,"wires":[[]]},{"id":"2652d3be.34560c","type":"subflow:92d4aa52.741878","z":"e89e1a81.ab1328","name":"ch3","env":[],"x":892.0195140838623,"y":310.00389671325684,"wires":[[]]},{"id":"be5e9236.200e7","type":"subflow:92d4aa52.741878","z":"e89e1a81.ab1328","name":"ch4","env":[],"x":887.017333984375,"y":366.0104064941406,"wires":[[]]},{"id":"32365555.427b8a","type":"tab","label":"nested 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I guess, there is no need for even one subflow...

Why do you handle temp. and humid. separately, when you do the same to them (double the value)?
Why not just double the value of every incoming msg and put it into the main switch node?

Also, i dont understand all the context operations - the topic info is always available in the msg...
and "msg = msg"...is not very helpful :slight_smile:

Anyway, i think you made some progress...

In the real device all sorts of operations will be done on temperature and power. This is just a simple example I made to understand how this works. If all I needed to do was multiply a number by 2 there are obviously much easier ways to do that. In general I just need to get temperature and power (and a bunch of other variables) into a flow so that the device can establish setpoints and run operations based on those setpoints.

Yes, the msg = msg was ridiculous, I have removed it. Thanks!

Here is the original thread that started all this subflow discussion. It has background on what I am looking to do with this multi-channel device: Join the json code from multiple flows into one file

But in general, are nested subflows bad, good, unreliable, or perfectly fine? I found one post on stack overflow where someone else is doing it... https://stackoverflow.com/questions/49559267/organize-subflows-in-palette

There's nothing wrong nesting subflows if it helps you organise, reuse and understand your flows.

The only rule is a subflow cannot contain directly or indirectly an instance of itself.

@cruxrider sorry, but i just coldnt see the benefit for using a subflow (or even nested) in your example - for me it seemed like the "msg = msg" just in a bigger dimension :slight_smile:

Looking forward to try your finished flow...