oldValue update

[gsierra (Gimena Sierra)]

Hi! I’ve been trying to get the last previous value of an attribute. So, if there was a modification from values “X01” to “X02” and finally “X03”, i always need to read the n-1 previous value, that would be “X02” here.

I tried using this transform, but i always get the first value there was in this attribute, for example X01. Code attached. Any idea? Thanks!

{
  "attributes": {
    "values": [
      "$oldValue",
      {
        "attributes": {
          "sourceName": "Mock-SAIP",
          "attributeName": "storeID"
        },
        "type": "accountAttribute"
      }
    ]
  },
  "type": "firstValid",
  "name": "oldValue firstValid"
}