Using wildcard in "put-metadata" header for PATCH / MergeThing command adds the metadata also for non-affected fields

[thjaeckle]

When e.g. using the following put-metadata header:

[{"key":"*/createdAt","value": "now!"}]

On a HTTP request:

PATCH /api/2/things/my:thing-1

E.g. sending the payload:

{
  "attributes": {
    "only-one": 2
  }
}

Will also lead to all existing fields in the Thing getting the metadata, e.g. as in:

{
  "_metadata": {
    "thingId": {
        "createdAt": "now!"
    },
    "policyId": {
        "createdAt": "now!"
    },
    "attributes": {
        "only-one": {
            "createdAt": "now!"
        }
    }
  }
}

That is unexpected and should instead only modify the metadata of the provided fields to "PATCH".

[sejal-bansal]

@thjaeckle I would like to work on this issue. Could you please assign it to me?

[thjaeckle]

@sejal-bansal cool, thanks
This however is probably not trivial to fix, I would assume.

[thjaeckle]

@sejal-bansal any update here? Do you work on this or shall I unassign the issue again?

[kulta4]

Hi @thjaeckle, @sejal-bansal!
I tried UpdateTwinWithLiveResponse mapper, [{"key":"/updated-via","value":"device-live-response"}] in put-metadata. I am facing error "message": "The wildcard expression '//updated-via' in header 'put-metadata' is not valid.",
how to fix this and I want to get the detailed implementation to achieve this in doc i have seen {
"dittoHeadersForMerge": {
"if-match": "",
"response-required": false,
"put-metadata": [
{"key":"/updated-by","value":"{{ request:subjectId }}"},
{"key":"/updated-via","value":"device-live-response"},
{"key":"/update-hint","value":"{{ header:some-custom-hint }}"},
{"key":"*/updated-at","value":"{{ time:now }}"}
]
}
} this much config example was there. can anyone help to do this properly