Update a single element in a virtual resource array?

I’m trying to use an edge action to update a single component of a virtual resource. For example, my virtual resource looks like this:


And I want to update/change the value of virtual/alarmVals/value/3538303131051215

So in my edge action write the following:

var returnPath = ""
var result = {}
returnPath = "vr://alarmVals/value/3538303131051215"
result[returnPath] = [{
        "alarms": {stuff},
        "setPoints": {stuff}
        "uuid": "something"
return result

But instead of updating the existing value, it adds a new “value” component to the json structure and slaps my new content there. Whatever I try for the path it always seems to add a new “value” key. Is this because I’m inserting an array? I haven’t been able to successfully update a VR not as an array…

Thanks for the help

Hello Lachlan,

Try something like this:

var telemetry = {
“alarms”: {stuff},
“setPoints”: {stuff}
“uuid”: “something”

return {
“vr://alarmVals/value/3538303131051215”: [telemetry] // or
“dh://virtual/alarmVals/value/3538303131051215”: [telemetry]

Hey David,

The first option gives me the same result and the second option doesn’t update the virtual resource at all.

Its as if it automatically adds a “/value” to the end of the path and adds the data there.

If I leave the path as “vr://alarmVals/value/3538303131051215”, it puts it at:

If I then update the path to “vr://alarmVals/value/3538303131051215/value”, it puts it at:

I already have a structure that doesn’t end with “/value”, so it seems like I cant update it without the system adding a new level. Is there a way to make it not do this? Is this the intentional behavior?

Hi lachlan,

To write to a Virtual Resource please use the following syntax:

return {
  "vr://myNewResource": ["Hi there!"]

You have syntax examples in the Edge Action editor page, at the bottom right select DOCUMENTATION and then “Create/update a virtual resource”.

vr:// automatically appends /value on purpose to ease the write.
Nested paths like /alarmVals/value/3538303131051215 are not supported.