How to add key/value of json object by node change

[minhhn0205]

Hi,
I would like to add key/value to the json object, I have done it using the function node.

[{"id":"828012fb.ba609","type":"tab","label":"フロー 1","disabled":false,"info":""},{"id":"b7825fef.5e89","type":"inject","z":"828012fb.ba609","name":"","topic":"","payload":"","payloadType":"str","repeat":"","crontab":"","once":false,"onceDelay":0.1,"x":370,"y":260,"wires":[["d20aed86.d3124"]]},{"id":"864f5526.8351b8","type":"function","z":"828012fb.ba609","name":"get data","func":"var arrVal = [];\narrVal.push('111');\narrVal.push('222');\narrVal.push('333');\nmsg.arrVal = arrVal;\n\nmsg.key = 'Data.txt';\nreturn msg;","outputs":1,"noerr":0,"x":680,"y":260,"wires":[["f517bb09.3554e8","d0c6dad4.d1bf48"]]},{"id":"d20aed86.d3124","type":"change","z":"828012fb.ba609","name":"","rules":[{"t":"set","p":"objFiles","pt":"msg","to":"{}","tot":"json"}],"action":"","property":"","from":"","to":"","reg":false,"x":520,"y":260,"wires":[["864f5526.8351b8"]]},{"id":"f517bb09.3554e8","type":"function","z":"828012fb.ba609","name":"store data","func":"msg.objFiles[msg.key] = msg.arrVal;\nreturn msg;","outputs":1,"noerr":0,"x":860,"y":220,"wires":[["671a7728.0305e8"]]},{"id":"671a7728.0305e8","type":"debug","z":"828012fb.ba609","name":"objFiles","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"objFiles","targetType":"msg","x":1000,"y":220,"wires":[]},{"id":"d0c6dad4.d1bf48","type":"change","z":"828012fb.ba609","name":"store data","rules":[],"action":"","property":"","from":"","to":"","reg":false,"x":860,"y":320,"wires":[[]]}]

Is this possible using change node?
Please tell me!
Thanks!

[E1cid]

Sure

[{"id":"d0c6dad4.d1bf48","type":"change","z":"828012fb.ba609","name":"store data","rules":[{"t":"set","p":"objFiles","pt":"msg","to":"{key: arrVal}\t","tot":"jsonata"}],"action":"","property":"","from":"","to":"","reg":false,"x":860,"y":320,"wires":[["671a7728.0305e8"]]}]

[knolleary]

An important clarification to the solution provided by @E1cid is that it will replace the whole msg.objFiles object with one containing just the one key/value pair.

In the context for the example flow you've provided, that is fine and also means you can get rid of the first Function node what initialises msg.objFiles to an empty object.

In the more general case, as you ask how to add a key/value property to a message property, that currently requires a bit more complex JSONata expression:

$merge([$.objFiles,{$.key: $.arrVal}])

In the 1.3 release, you'd be able to do this without JSONata by setting the msg. type to: msg.objFiles[msg.key]

[minhhn0205]

@E1cid, @knolleary Thank your for your support!

Great!!!
Maybe jsonata can do it all @@

[minhhn0205]

@knolleary

In the 1.3 release, you'd be able to do this without JSONata by setting the msg. type to: msg.objFiles[msg.key]

One useful information I will keep in mind.
Thank you!