Hello, Is there a way to dynamically set a property in a change node? Something like: set flow.mode[msg.targetMode].enabled to msg.payload I know I can do it in javascript, but it would be better with a change node. Thank you Andy

This is possible with a jsonata expression ($eval) - here you can see an example: [image] Allow target to be also a jsonata expression Feature Requests In the source field i can enter something like this: $eval(payload[0].payload.cfg.p1,payload[1]) which returns a field …

Thanks for the quick answer. I tried, but it not seams to work. I try something like: on the for or on the msg: $eval(topic) or $eval(msg.topic) to msg.payload msg.topic containing "vip" msg.payload containing "hello" It results: flow.$eval(topic) = "hello" Do you have a more basic exemple? W…

Just show me what you tried (as exported flow). Also, which version of n-r do you have?

We are on 0.20.3 Here's the flow: [{"id":"e9f00787.c7d228","type":"inject","z":"92c036c9.c74c08","name":"","topic":"","payload":"","payloadType":"date","repeat":"","crontab":"","once":false,"onceDelay":0.1,"x":480,"y":200,"wires":[["2d2b521.79b6fae"]]},{"id":"2d2b521.79b6fae","type":"change","z":"…

I wonder if eval is really needed? Is this what you want? Note that the key targetMode in the second rule is evaluated (not literal). [p-01] [p-02]

That won't do, because if the mode bbb already exists, with other properties, they get erased. The jsonata expression recreate the bbb property entirely instead of just targetting a sub-property. Here's an exemple [{"id":"e9f00787.c7d228","type":"inject","z":"92c036c9.c74c08","name":"","topic":"",…

Simplified dynamic property example: [{"id":"b585fa52.babdb8","type":"inject","z":"c421dfeb.3e752","name":"","topic":"lala","payload":"{\"topic\": \"testtopic\"}","payloadType":"json","repeat":"","crontab":"","once":false,"onceDelay":0.1,"x":402,"y":3350,"wires":[["aaf0b982.837278","8cc8db27.ee65e8…

[image] Andydesjardins: That won't do, because if the mode bbb already exists, with other properties, they get erased. The jsonata expression recreate the bbb property entirely instead of just targetting a sub-property. Indeed, fully agree.

@moebius I don't understand your flow sample. It seems it just take the property topicfield and us it as a value to overrite the topic with it. But the point would be to take the value of topicfield and use it as a dynamic reference to a propperty, so I could set the value with another property to…

Well, it looks like you dont want to "dynamically set a property" as you wrote in the title of your thread... Seems like you want to create a property dynamically. So you can support my feature request :slight_smile: Meanwhile, this is only possible with a function node afaik.

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Change node: dynamically set a property

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moebius 21 May 2019 15:23 2

This is possible with a jsonata expression ($eval) - here you can see an example:

Topic		Replies	Views
Allow target to be also a jsonata expression Feature Requests	6	1607	22 April 2020
File-in node drops payload properties? General	6	372	15 October 2019
Use part of msg.xxx as name of flow variable to be changed General	13	966	6 October 2020
[Feature Request]Add ability to use JSONata and/or $Env in Change node Feature Requests	19	363	13 November 2023
Change node, modify message property General	10	1610	28 December 2020

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Change node: dynamically set a property

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