Need help combining two msg with arrays

[network_potato]

I have two messages that each have an array that is called the same (line_items).

I need to combine them so that I get one message, with an array called line_items, that has both of the objects inside it.

I have tried using the join node in manual mode with different type of settings, but the closest I can get is this, where the arrays are placed inside a new array:

But I need the objects to be in the array directly (in the "root", if that makes sense?)
Like this (photoshopped):

[Steve-Mcl]

How do you differentiate them?

Do they come from the same node wire or separate wires?

show a picture of the flow where the messages come from

Without this info, we would be guessing.

[Ithoh]

Hello,

Assuming you have only two items, you can come up with something like this using a function node, It might not be the best way to do it, but you can give it a try I guess !

(For my method to work you'll need to have differents topics name on your messages to be able to differentiate them, and also I deleted my previous post cause I made a mistake)

[{"id":"a877e7f86dc43baa","type":"inject","z":"4649623030b5e549","name":"","props":[{"p":"payload.line_items","v":"[{\"item1\":\"item1\"}]","vt":"json"},{"p":"topic","vt":"str"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"item1","x":310,"y":1000,"wires":[["96c64f3e38f8254a"]]},{"id":"f0ad6519098139b0","type":"inject","z":"4649623030b5e549","name":"","props":[{"p":"payload.line_items","v":"[{\"item2\":\"item2\"}]","vt":"json"},{"p":"topic","vt":"str"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"item2","x":310,"y":1060,"wires":[["96c64f3e38f8254a"]]},{"id":"5416325db8307a6f","type":"debug","z":"4649623030b5e549","name":"","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"true","targetType":"full","statusVal":"","statusType":"auto","x":710,"y":1040,"wires":[]},{"id":"96c64f3e38f8254a","type":"function","z":"4649623030b5e549","name":"","func":"var local_msg = RED.util.cloneMessage(msg);\nflow.set(local_msg.topic, local_msg);\n\nvar item1 = flow.get(\"item1\") || \"\";\nvar item2 = flow.get(\"item2\") || \"\";\n\nvar new_item = {};\nnew_item.payload = {};\nnew_item.payload.line_items = [];\n\nif(item1.topic === \"item1\" && item2.topic === \"item2\"){\n    new_item.payload.line_items.push(item1.payload.line_items[0])\n    new_item.payload.line_items.push(item2.payload.line_items[0])\n\n    return new_item;\n}\n\n","outputs":1,"noerr":0,"initialize":"","finalize":"","libs":[],"x":520,"y":1040,"wires":[["5416325db8307a6f"]]}]

[network_potato]

Thank you! This works perfectly if both item1 and item2 exist.

However, in some cases, only a message with topic of item1 exists. In such cases, I want the message (item1) to be passed through (right now, the function node waits for item2 to arrive, which it never will).

Is that possible to do?

Like this:

[zenofmud]

What will determine if msg2 is not gong to show up?

[network_potato]

I do a check earlier in the flow where a change node looks for a certain item in the message, if the value of that item is greater than 0, the message passes on.

[zenofmud]

Then I would put a switch node in to test that condition and bypass the join node if it was true otherwise go to the join node.

[network_potato]

Thank you for the solution, it works.