Change node, modify message property

General
1

I know I have asked before, but can't remember the exact wording.

Only to save using nodes, I want to change a message property in a change node.

So what I want to do:

I am getting msg.delay and multiply it by 1000.

I know I have to enter it in the J: expression part, but.... That's the limit.

I'll try a could of things, but I know the system is if I don't ask I won't remember.
If I do ask, before I get an answer the probability of me remembering will go up.

2

Remembered:

msg.delay = msg.delay * 1000

Couldn't really be easier.

3

Please explain how the above expression is the solution to modifying msg.delay in a change node?

Using that expression in a change node will modify the property value to false, it will not multiply it by 1000.

Use delay * 1000 in the JSONata expression.

What you posted will work in a function node, but your question was for a change node. I had to say something as your solution may confuse others looking for a solution to modifying in a change node.

[{"id":"b95ccd5.63ef1b","type":"inject","z":"8d22ae29.7df6d","name":"","props":[{"p":"delay","v":"4","vt":"num"},{"p":"topic","vt":"str"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","x":140,"y":1940,"wires":[["70ea60b1.134808"]]},{"id":"70ea60b1.134808","type":"change","z":"8d22ae29.7df6d","name":"","rules":[{"t":"set","p":"payload","pt":"msg","to":"delay * 1000","tot":"jsonata"},{"t":"set","p":"delay","pt":"msg","to":"msg.delay = msg.delay * 1000","tot":"jsonata"}],"action":"","property":"","from":"","to":"","reg":false,"x":340,"y":1940,"wires":[["be48273.628c958"]]},{"id":"be48273.628c958","type":"debug","z":"8d22ae29.7df6d","name":"","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"true","targetType":"full","statusVal":"","statusType":"auto","x":560,"y":1940,"wires":[]}]
4

In fairness, Andrew did say...

5

I fail to see your point. Entering a Javascript expression into a JSONata expression box still will not work, and the solution is confusing to other users.

6

Sorry, yes, you are right, I am assuming (since he said it works) that he didnt actually put msg.delay = msg.delay * 1000 into the expression (as it wouldnt work). I read this as he set msg.delay to msg.delay * 1000 using J: expression.

but yes, you are right to clarify - it is a bit unclear for those not reading between the lines.

7

To clarify msg.delay * 1000will not work either.

8

It does.

image

image

[{"id":"e71f4e83.15362","type":"inject","z":"f77cda4d.5d7628","name":"delay: 2","props":[{"p":"payload"},{"p":"delay","v":"2","vt":"num"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","payload":"","payloadType":"date","x":1190,"y":260,"wires":[["464da612.cf3418"]]},{"id":"464da612.cf3418","type":"change","z":"f77cda4d.5d7628","name":"","rules":[{"t":"set","p":"payload","pt":"msg","to":"msg.delay * 1000","tot":"jsonata"}],"action":"","property":"","from":"","to":"","reg":false,"x":1210,"y":300,"wires":[["ff13eed3.37ddd"]]},{"id":"ff13eed3.37ddd","type":"debug","z":"f77cda4d.5d7628","name":"","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"true","targetType":"full","statusVal":"","statusType":"auto","x":1230,"y":340,"wires":[]}]
9

Apology, It does indeed work. I never use msg in JSONata as it is not needed.

10

No its not, but if memory serves, it is there for backwards compatibility.

11

Wow.... Ok.

I am using the change node and I needed to change things.

This is the part of the flow in question:

[{"id":"7f22aa5b.695bbc","type":"ui_slider","z":"ae12fd.00ef75","name":"Sydney","label":"Frequency (m)","tooltip":"","group":"ebcaab30.c904b","order":2,"width":3,"height":1,"passthru":false,"outs":"end","topic":"","min":"1","max":"30","step":1,"x":420,"y":3820,"wires":[["4acbf31d.4b45b4"]]},{"id":"4acbf31d.4b45b4","type":"change","z":"ae12fd.00ef75","name":"convert to minutes","rules":[{"t":"move","p":"payload","pt":"msg","to":"delay","tot":"msg"},{"t":"set","p":"delay","pt":"msg","to":"msg.delay * 60000","tot":"jsonata"}],"action":"","property":"","from":"","to":"","reg":false,"x":525,"y":3820,"wires":[["110b9f17.9c9241"]],"l":false},{"id":"110b9f17.9c9241","type":"trigger","z":"ae12fd.00ef75","name":"Variable","op1":"trigger","op2":"0","op1type":"str","op2type":"str","duration":"-30","extend":false,"overrideDelay":true,"units":"s","reset":"","bytopic":"all","topic":"topic","outputs":1,"x":630,"y":3820,"wires":[["f57d4697.23dda"]]},{"id":"ebcaab30.c904b","type":"ui_group","name":"Sydney weather","tab":"de0f6b36.132fa8","order":2,"disp":true,"width":"8","collapse":false},{"id":"de0f6b36.132fa8","type":"ui_tab","name":"Weather","icon":"dashboard","order":17,"disabled":false,"hidden":false}]

The slider node outputs msg.payload and I need it to be msg.delay to adjust the delay time on the trigger node.

But I don't want to send numbers that big to control the delay/repeat time from 1 minute to 30 minutes.

So, the change node moves msg.payload to msg.delay. (Line 1)
(Line 2) multiplies msg.delay by 60000 to make the number for minutes.