# Help with some JS code
**URL:** https://discourse.nodered.org/t/help-with-some-js-code/101785
**Category:** General
**Created:** [15 September 2026 08:42 UTC](https://discourse.nodered.org/t/help-with-some-js-code/101785 "2026-09-15T08:42:36Z")
**Posts on this page:** 10
**Page:** 1
### Author:  [@Trying\_to\_learn](https://discourse.nodered.org/u/Trying_to_learn)
#### Post date: [15 September 2026 08:42 UTC](https://discourse.nodered.org/t/help-with-some-js-code/101785/1 "2026-09-15T08:42:36Z")
Hey folks.
Need some help.
I have a "smart" TV (cough) but it is ONLY used for displaying.
It has 4 HDMI inputs.
I have an NVidia shield plugged into HDMI1.
I have an Amp with multiple HDMI inputs plugged into HDMI2.
HDMI2 is the _usual_ input.
That has Foxtel plugged into it.
I use the Foxtel remote to control things. HDMI CEC.
I can detect if the TV is OFF/ON.
The shield is usually turned off.
_NORMAL_ use the Foxtel is wateched mostly.
Now and then I turn on the shield to watch local stuff.
_Problem_
I can't really cheat to know when it is turned off as it still allows PING replies, so.....
I'm stuck with this point.
What happens.
I power on the shield and it starts returning PING values.
That indicates it is ON.
It also turns on the TV and it (The TV) adjusts its input to HDMI1.
I don't always turn off the Shield (power down) when not using it.
So, I turn on the Foxtel, and this is where things get complicated.
It sets itself to HDMI2 input, but doesn't get it exact.
I control the _TV_ (Foxtel) also via HDMI CEC for channel changes, etc.
So the input selection needs to be correct. Not _Generic_.
To get around this I have a `mode` mode for the TV (flow context) to indicate the desired input.
Going to Shield input works fine. Going back to Foxtel mode doesn't.
To recap:
_Normal_ mode (Foxtel) is active.
I turn on (power it on) the shield and the TV adjusts its input.
NR blocks any _usual_ Foxtel/TV commands as they are channel changes.
It indicates it is set to SHIELD mode.
So I want to go back to Foxtel.
I pick up the Foxtel remote and _Power it on_.
The TV adjusts its input to the _GENERIC_ HDMI input, but it isn't the exact one.
I don't think I can fix this EXACT problem as described.
But I'm wanting to get some code that - if the MODE is set to FOXTEL - tweaks what happens when the TV is powered on for the _first time_ to set the correct input.
_WHAT?_
As in:
It is in SHIELD mode, but turned off.
I power on the TV but it is set to FOXTEL mode.
It sends some extra commands to tweak the input to the correct one.
Without posting the entire code - not fair to you - I just want some help with one bit of JS code in a `function` node.
```auto
//////////////////////////////////////////////////////////
// 2026 09 15 //
// ========== //
// //
// Addition/modification to code. //
// ------------------------------ //
// //
// Outputs: //
// 1 - Message to voice //
// 2 - Output to input changer code //
// //
// //
// Variables: //
// `shield` - status of the shield. //
// `tvstate` - status of the tv. //
// `tvmode` - mode set for tv input. //
// `flag` - used to stop resending of same message that day. //
// //
// Still to do: //
// Need code to detect tv input was on `shield` but //
// shield is off and tv is ON/`true` and send the //
// A.I.C. command to change input on TV. //
//
// get values needed.
const shield = flow.get("SHIELD")
const tvstate = flow.get("TVState")
const tvmode = flow.get("TV_MODE")
let flag = context.get("flag") || 0
// store then in context only to help tracking.
context.set("shield",shield)
context.set("tvstate",tvstate)
context.set("tvmode",tvmode)
const msgA = "Warning. Shield detected. Mode set for Foxtel"
const msgB = "Please check TV is set to FOXTEL input and not just set to Onkyo"
const msgCC = "Change TV input"
const alert = "bellding.mp3"
//let mute = 0
//node.warn("Shield state " + shield)
//node.warn("TV state " + tv)
//node.warn("TV mode " + mode)
// TV off
if (tvstate == false)
{
//
node.status({})
context.set("flag",0)
node.status({ fill: "red", shape: "dot", text: "OFF" });
return
}
// mode mismatch - first time
if (shield == "ON" && tvstate == true && tvmode == "FOXTEL" && flag == 0)
{
//node.warn("HERE")
// This is maybe where the signal needs to go (output 2) to signal the TV input tweak?
node.status({fill:"red"})
// msg.payload = "Warning. Shield detected. Mode set for Foxtel"
msg.payload = msgA
msg.mute = 1
msg.alert = alert
node.status({ fill: "red", shape: "dot", text: "Mismatch" })
context.set("flag",1)
return msg
}
// Shield - all good - first time
if (shield == "ON" && tvstate == true && tvmode == "SHIELD" && flag == 0)
{
//
node.status({fill:"green", text: "Shield"})
context.set("flag",0)
return
}
// Shield - all good - WHY NEEDED?
if (shield == "ON" && tvstate == true && tvmode == "SHIELD" && flag == 1)
{
//
node.status({ fill: "green", text: "Shield" })
context.set("flag", 0)
return
}
// Foxtel - all good - first time
if (shield == "OFF" && tvstate == true && tvmode == "FOXTEL" && flag == 0)
{
// This needs work to send message to adjust TV input
// msgCC needed in this part of the code sent out of second output
// and msgB is sent on first output
node.status({fill:"yellow", text: "Foxtel"})
return
}
```
Sorry for some of the commented lines. I'm still testing the waters. 😉
I'm confused.
This NEARLY is what I want.
But it doesn't have the input for when I change the mode from SHIELD to FOXTEL.
(Isn't hard, but I'm just saying. This is where I'm at.)
Thoughts?
---
### Author:  [@dynamicdave](https://discourse.nodered.org/u/dynamicdave)
#### Post date: [15 September 2026 10:48 UTC](https://discourse.nodered.org/t/help-with-some-js-code/101785/2 "2026-09-15T10:48:11Z")
I've run it through AI and got this response and possible improvement...
> **[Check out this chat](https://chatgpt.com/share/6aa9222e-daa8-83ed-8c87-2d739ad43dab)**
>
> Here's a chat someone thought you'd want to see.
---
### Author:  [@Trying\_to\_learn](https://discourse.nodered.org/u/Trying_to_learn)
#### Post date: [15 September 2026 11:05 UTC](https://discourse.nodered.org/t/help-with-some-js-code/101785/3 "2026-09-15T11:05:17Z")
Thanks Dave.
I wasn't wanting to go down the `chatGPT` rabbit hole - not that I haven't.
I just don't want to become _dependant_ on it.
I really haven't worked out the exact workings of the big picture.
Note: exact.
It is a weird scenario which I can't fully understand just now.
It is annoying/painful that I can't detect the shield being _OFF_ (as in software wise) and **O** **F** **F** (fully powered down.)
## EDIT!
Sorry, I can. It either PINGS or it doesn't.
Likewise with the Foxtel, I don't get any signals from it saying it is _ON_ or _OFF_.
And - alas - the TV doesn't tell me what it is seeing on its inputs.
The fixed / known things are:
If the shield is turned on (either from no power or from sleep mode) the TV is turned on and the correct input is selected.
If the shield has been _USED_ and the input is set for it, and the Foxtel is turned on......
The TV needs a slight nudge to its selected input. But only for the FIRST time, as subsequent times the input will be correct.
But knowing exactly the microscopic details of that is .... _impossible_.
Other than the flow context of `TV_STATE`
Which I have to change manually.
And that opens a new _can of worms_ in that if/when I do that.
Before the Foxtel is turned on or after.
Either way, the input on the TV needs to be _tweaked_.
But the handling of all that.......
Still fog for me.
Which is why I'm asking here.
Rather than brain rot myself with `chatgtp`..... human to human interaction and _spit balling_.
😉
What I posted is about .... 30% of the whole thing.
The `TV_MODE` is set else where.
Does that help or just make it more vague than it was?
---
### Author:  [@mudwalker](https://discourse.nodered.org/u/mudwalker)
#### Post date: [15 September 2026 11:16 UTC](https://discourse.nodered.org/t/help-with-some-js-code/101785/4 "2026-09-15T11:16:51Z")
You don't have to 'Brain Rot' yourself.
I get a flow and then understand how it works before I use it in my flows. It is surprising oaw you can save yourself effort in writing your own Functions when you understand what AI has given you!!
---
### Author:  [@Trying\_to\_learn](https://discourse.nodered.org/u/Trying_to_learn)
#### Post date: [15 September 2026 11:18 UTC](https://discourse.nodered.org/t/help-with-some-js-code/101785/5 "2026-09-15T11:18:47Z")
True.
I am - probably - being harsh on myself.
I'm - just now - talking to ChatGPT with the new code Dave posted.
I've found a couple of problems and am working on the solutions now.
---
### Author:  [@Trying\_to\_learn](https://discourse.nodered.org/u/Trying_to_learn)
#### Post date: [15 September 2026 11:42 UTC](https://discourse.nodered.org/t/help-with-some-js-code/101785/6 "2026-09-15T11:42:50Z")
Wow, this chatgpt is different to the one I _use_.
When I copy code, I get the leading ``` marks too.
(Strange)
(I deleted it to help it _work_ here)
But the first line was
'''javascript
Ok, that isn't working.
But replace the ' with a ` and you get it.
the new code is:
```auto
//////////////////////////////////////////////////////////
// 2026 09 15 //
// ========== //
// //
// TV / SHIELD / FOXTEL control //
// //
// Outputs: //
// 1 - Message to voice //
// 2 - Output to A.I.C. input changer //
// //
// IMPORTANT //
// TV_MODE is remembered while the TV is ON //
// before the TV is turned OFF //
// //
// When the TV is turned ON again, the remembered //
// mode can be used to decide what action is needed //
// //
//////////////////////////////////////////////////////////
// ------------------------------------------------------
// Get current values
// ------------------------------------------------------
const shield = flow.get("SHIELD")
const tvstate = flow.get("TVState")
const tvmode = flow.get("TV_MODE")
// ------------------------------------------------------
// Get values stored in context
// ------------------------------------------------------
// Flag used to prevent sending the same A.I.C. command
// repeatedly
let flag = context.get("flag") || 0
// Remember the TV_MODE from the previous TV ON state
let previousTVMode = context.get("previousTVMode") || null
// Remember the previous TV state
let previousTVState = context.get("previousTVState")
// ------------------------------------------------------
// Store current values for tracking
// ------------------------------------------------------
context.set("shield", shield)
context.set("tvstate", tvstate)
context.set("tvmode", tvmode)
// ------------------------------------------------------
// Messages
// ------------------------------------------------------
const msgA = "Warning. Shield detected. Mode set for Foxtel"
const msgB = "Please check TV is set to FOXTEL input and not just set to Onkyo"
const msgCC = "Change TV input"
const alert = "bellding.mp3"
// ------------------------------------------------------
// Detect TV ON -> OFF
//
// Before the TV goes OFF, remember the current TV_MODE
//
// This is important because TV_MODE may change, disappear,
// or become unreliable while the TV is OFF
// ------------------------------------------------------
if (
previousTVState === true &&
tvstate === false
)
{
// Only remember the mode if it is a valid known mode
if (
tvmode === "SHIELD" ||
tvmode === "FOXTEL"
)
{
context.set("previousTVMode", tvmode)
previousTVMode = tvmode
}
node.status({
fill: "red",
shape: "dot",
text: "TV OFF"
})
// A new TV ON cycle can have a new A.I.C. event
context.set("flag", 0)
// Store current state
context.set("previousTVState", tvstate)
return [null, null]
}
// ------------------------------------------------------
// TV OFF
//
// Nothing else happens while the TV remains OFF
//
// IMPORTANT:
// Do NOT overwrite previousTVMode here
// ------------------------------------------------------
if (tvstate !== true)
{
node.status({
fill: "red",
shape: "dot",
text: "TV OFF"
})
context.set("previousTVState", tvstate)
return [null, null]
}
// ------------------------------------------------------
// TV has just changed from OFF -> ON
//
// This is where we use the TV_MODE remembered from the
// previous ON state.
//
// Example:
//
// TV was ON
// TV_MODE = SHIELD
// TV turned OFF
// SHIELD turned OFF
// TV turned ON
//
// previousTVMode will still be "SHIELD"
//
// This allows us to act on what the TV WAS using,
// rather than relying on the current TV_MODE
// ------------------------------------------------------
if (
previousTVState === false &&
tvstate === true
)
{
node.status({
fill: "blue",
shape: "dot",
text: "TV ON"
})
// --------------------------------------------------
// TV was previously using SHIELD
//
// If SHIELD is now OFF, send the A.I.C. command
//
// This is the important condition
// --------------------------------------------------
if (
previousTVMode === "SHIELD" &&
shield === "OFF" &&
flag === 0
)
{
const aicMsg = {
payload: msgCC
}
context.set("flag", 1)
context.set("previousTVState", tvstate)
return [null, aicMsg]
}
}
// ------------------------------------------------------
// SHIELD ON + TV ON + TV MODE = FOXTEL
//
// Shield has been detected but TV is still on FOXTEL.
//
// Voice warning only.
//
// NO A.I.C. command here.
// ------------------------------------------------------
if (
shield === "ON" &&
tvstate === true &&
tvmode === "FOXTEL" &&
flag === 0
)
{
const voiceMsg = {
payload: msgA,
mute: 1,
alert: alert
}
context.set("flag", 1)
node.status({
fill: "red",
shape: "dot",
text: "Shield / FOXTEL mismatch"
})
context.set("previousTVState", tvstate)
return [voiceMsg, null]
}
// ------------------------------------------------------
// SHIELD ON + TV ON + TV MODE = SHIELD
//
// Everything is correct
// ------------------------------------------------------
if (
shield === "ON" &&
tvstate === true &&
tvmode === "SHIELD"
)
{
context.set("flag", 0)
node.status({
fill: "green",
shape: "dot",
text: "Shield"
})
// Remember the current valid mode
context.set("previousTVMode", tvmode)
context.set("previousTVState", tvstate)
return [null, null]
}
// ------------------------------------------------------
// SHIELD OFF + TV ON + TV MODE = FOXTEL
//
// Everything is correct
// ------------------------------------------------------
if (
shield === "OFF" &&
tvstate === true &&
tvmode === "FOXTEL"
)
{
context.set("flag", 0)
node.status({
fill: "yellow",
shape: "dot",
text: "Foxtel"
})
// Remember the current valid mode
context.set("previousTVMode", tvmode)
context.set("previousTVState", tvstate)
return [null, null]
}
// ------------------------------------------------------
// TV is ON
//
// If TV_MODE is known, remember it.
//
// This catches normal changes while the TV remains ON.
// ------------------------------------------------------
if (
tvstate === true &&
(
tvmode === "SHIELD" ||
tvmode === "FOXTEL"
)
)
{
context.set("previousTVMode", tvmode)
}
// ------------------------------------------------------
// Store current TV state
// ------------------------------------------------------
context.set("previousTVState", tvstate)
return [null, null]
```
I'm working through it now.
---
### Author:  [@dynamicdave](https://discourse.nodered.org/u/dynamicdave)
#### Post date: [15 September 2026 12:12 UTC](https://discourse.nodered.org/t/help-with-some-js-code/101785/7 "2026-09-15T12:12:17Z")
You'll have to top and tail the code by removing...
**```javascript** at the top
and
**```** at the bottom of the listing.
---
### Author:  [@Trying\_to\_learn](https://discourse.nodered.org/u/Trying_to_learn)
#### Post date: [15 September 2026 12:13 UTC](https://discourse.nodered.org/t/help-with-some-js-code/101785/8 "2026-09-15T12:13:08Z")
Strange, as I have never had to do that before myself.
---
### Author:  [@mudwalker](https://discourse.nodered.org/u/mudwalker)
#### Post date: [15 September 2026 12:48 UTC](https://discourse.nodered.org/t/help-with-some-js-code/101785/9 "2026-09-15T12:48:53Z")
Make sure you at least have a good idea of what the code is doing. I find my Debug Nodes and msg.test(x) get a hammering while understanding!
Good Luck.
---
### Author:  [@CincellaAiazzi](https://discourse.nodered.org/u/CincellaAiazzi)
#### Post date: [16 September 2026 04:54 UTC](https://discourse.nodered.org/t/help-with-some-js-code/101785/10 "2026-09-16T04:54:58Z")
> [@Trying\_to\_learn](#):
>
> I wasn't wanting to go down the `chatGPT` rabbit hole - not that I haven't.
> I just don't want to become _dependant_ on it.
Sorry for going slightly off-topic, but this sentence made me smile....
I have to admit, “I don't want to become dependent on ChatGPT” sounds wonderfully old-school.
A bit like saying: “I prefer to solve problems myself”… and then opening a forum thread to ask other people how to solve the problem.
Apparently the important thing is that ChatGPT reaches you through at least one human intermediary. 😄