So I'm testing if global.test is of type undefined with switch node and if it is, I then want to create it as an empty object
But I can't come up with a method without using function node
Is there one?
Could you use the change node?
And how would I use the change node to do it?
Like this:
[
{
"id": "84d68cafac8af5c6",
"type": "change",
"z": "0918ee609bf69fc7",
"name": "",
"rules": [
{
"t": "set",
"p": "your_name",
"pt": "global",
"to": "[ ]",
"tot": "json"
}
],
"action": "",
"property": "",
"from": "",
"to": "",
"reg": false,
"x": 1420,
"y": 4460,
"wires": [
[]
]
}
]
Oh, sorry... Ok.
Put a SWITCH node before this to test if the global name undefined.
Like this:
[{"id":"84d68cafac8af5c6","type":"change","z":"0918ee609bf69fc7","name":"","rules":[{"t":"set","p":"your_name","pt":"global","to":"[ ]","tot":"json"}],"action":"","property":"","from":"","to":"","reg":false,"x":1440,"y":4480,"wires":[[]]},{"id":"58014e2d35c563c7","type":"switch","z":"0918ee609bf69fc7","name":"","property":"your_name","propertyType":"global","rules":[{"t":"istype","v":"undefined","vt":"undefined"}],"checkall":"true","repair":false,"outputs":1,"x":1220,"y":4480,"wires":[["84d68cafac8af5c6"]]}]
Yeah, ok, you said you are using the switch.
I am really not parsing things too good still.
But I hope that did help - even a little.
That's close but not quite what I'm after
Your solution gives me an object with an array (albeit empty one) in it
I'm after a completely empty object
Like what you get if you use
global.set('homemadeSub', {}); in a function node
I put a between the [ ] only because of habits.
No space between them any better?
Sorry.
Just offering ideas.
[]doesn't work either - still gives an empty array
Sorry. Above my skill set.
What's the reason behind not wanting to use a function node?
Last minute thought:
This way?
[{"id":"84d68cafac8af5c6","type":"change","z":"0918ee609bf69fc7","name":"","rules":[{"t":"set","p":"your_name","pt":"global","to":"{}","tot":"jsonata"}],"action":"","property":"","from":"","to":"","reg":false,"x":1440,"y":4480,"wires":[[]]}]
Not for me
Thanks - that does the job 
I always want to do stuff in NR without function nodes if possible - I can't tupe very well
1 Like
No problems.
Glad I could help.
All the best.
That's odd, I get the same result using either
or
Apologies - your right - I was trying so many things!
I probably tried entering that but forgot to press deploy when I tested it
1 Like
I get confused when I see JSON in the dropdown as in my mind, JSON is text and not an object so I didn't think to try it out thoroughly
Have a look at this change node snippet of a flow:
[{"id":"ab01324c.4824","type":"inject","z":"1d66267b.4c5caa","name":"","topic":"","payload":"90","payloadType":"num","repeat":"","crontab":"","once":false,"onceDelay":0.1,"x":130,"y":100,"wires":[["3280794c.eb6396"]]},{"id":"3280794c.eb6396","type":"change","z":"1d66267b.4c5caa","name":"Convert Wind Direction in Degrees To Cardinal points","rules":[{"t":"set","p":"directions","pt":"flow","to":"$exists($flowContext(\"directions\")) ? $flowContext(\"directions\") : [\"N\", \"NNE\", \"NE\", \"ENE\", \"E\", \"ESE\", \"SE\", \"SSE\", \"S\", \"SSW\", \"SW\", \"WSW\", \"W\", \"WNW\", \"NW\", \"NNW\"] ","tot":"jsonata"},{"t":"set","p":"index","pt":"msg","to":"$string($floor((payload / 22.5) + 0.5) % 16)","tot":"jsonata"},{"t":"set","p":"payload","pt":"msg","to":"$flowContext(\"directions[\"&index&\"]\")","tot":"jsonata"}],"action":"","property":"","from":"","to":"","reg":false,"x":420,"y":100,"wires":[["10a54176.da8daf"]]},{"id":"10a54176.da8daf","type":"debug","z":"1d66267b.4c5caa","name":"","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"true","targetType":"full","x":690,"y":120,"wires":[]}]
1 Like
The clue is certainly given in the name
JSON is certainly gives an object. And a JavaScript object can, mostly, be considered equivalent. The exceptions being that JSON is serializable (hence the text thing) whereas some JS objects are not. As so often in the weird world of JavaScript, you have two concepts that are nearly but not quite the same. :sigh:
Your not going to start a "JSON" vs "JS Object" language argument are you?
JSON is NOT an object - it's a text description of an object
And even I know this and I know NOTHING!
I modded your suggestion which save me having to use a switch node before the change node to test if it exists
[orig]
[corrected]
Good grief! That Jsonata expression is nearly understandable. 
2 Likes
