Check uniqueness with in nested object property values in array of objects

Question

I am returning null if an array of objects has the same property values and is fine with the direct object properties. I am trying with nested object property values in the same array, but it is failing. Below is the code for the same.

const getNullOrUniquePropertyValue = (arrToCheck, keyName, includeFullObject = null) => {
  const uniqueValues = [...new Set(arrToCheck.map((v) => v[keyName]))];
  if (uniqueValues.size !== 1) {
    return null;
  }
  return includeFullObject ? arrToCheck[0].includeFullObject : arrToCheck[0].keyName;
};

And I am calling above function like as below

getNullOrUniquePropertyValue(
      spaces,
      'designHubProjectSpaceTypeId'
    )

I am getting results as null for the above function because designHubProjectSpaceTypeId is not the same in the array.

I am passing nested objects property like as below, and it is returning null for below condition even if the array has both same values.

 getNullOrUniquePropertyValue(spaces, 'spaceGeometry.ceilingHeight')

and the space structure like this as below

"spaces": [
    {
      "spaceGeometry": {
        "ceilingHeight": 9
      },
      "designHubProjectSpaceTypeId": "some Id"
    },
    {
      "spaceGeometry": {
        "ceilingHeight": 9
      },
      "designHubProjectSpaceTypeId": "some other Id"
    }
  ]

Could anyone please let me know where I am doing wrong with the above code?

Many thanks in advance!!

Please post the full JSON object, or try to make it run able via the code snippet. — NVRM, Oct 21 '21 at 00:32
You can't just use a string with a dot in it and expect it to access the implied nested property. `obj['spaceGeometry.ceilingHeight']` literally looks for a single property `{'spaceGeometry.ceilingHeight': 'value'}`. You'll need to manually parse the strings and access the nested properties. — pilchard, Oct 21 '21 at 01:04

Ro Milton · Accepted Answer · 2021-10-21T01:34:03.943

Some feedback:

v[keyName] isn't going to work if keyName is a string with a dot ("spaceGeometry.ceilingHeight"), you'll have to split the string and lookup the value at each level manually
uniqueValues is an array not a set, so use .length instead of .size

I made a simple function getNestedValue() that uses reduce to extract a nested value from an object.

const spaces = [
  {
    "spaceGeometry": {
      "ceilingHeight": 9
    },
    "designHubProjectSpaceTypeId": "some Id"
  },
  {
    "spaceGeometry": {
      "ceilingHeight": 9
    },
    "designHubProjectSpaceTypeId": "some other Id"
  }
];

const getNestedValue = (obj, path) => path.split(".").reduce((accum, key) => accum[key], obj);

const getNullOrUniquePropertyValue = (arrToCheck, keyName) => {
  const uniqueValues = [...new Set(arrToCheck.map((v) => getNestedValue(v, keyName)))];
  if (uniqueValues.length !== 1) {
    return null;
  }
  return uniqueValues[0];
};

const result = getNullOrUniquePropertyValue(
  spaces,
  'spaceGeometry.ceilingHeight'
);
    
console.log(result);

I omitted includeFullObject from my example because it's not relevant to this particular issue, and I'm unclear what it's supposed to do. If you're having issues with that part too, let me know the details and I can help.

Check uniqueness with in nested object property values in array of objects

1 Answers1