Flatten an object using lodash

Question

I have below this nested object

I need to create an array using this object containing keys. And if keys are object then it should use .d

Answer 1

You can create a recursive function (getSchema) that checks if a value (val) is an object (arrays included), iterate it with _.flatMap(), and collects the keys until it hits a value which is not an object. It then joins the collected keys and returns the string.

const getSchema = (val, keys = []) =>
  _.isObject(val) ? // if it's an object or array
    _.flatMap(val, (v, k) => getSchema(v, [...keys, k])) // iterate it and call fn with the value and the collected keys
    :
    keys.join('.') // return the joined keys

const invoiceObject = { "AllowIPNPayment": false, "AllowOnlinePayment": false, "AllowOnlineCreditCardPayment": false, "AllowOnlineACHPayment": false, "domain": "QBO", "sparse": false, "Id": "16", "SyncToken": "1", "MetaData": { "CreateTime": "2020-03-25T15:10:40-07:00", "LastUpdatedTime": "2020-03-26T11:06:49-07:00" }, "CustomField": [{ "DefinitionId": "1", "Name": "Crew #", "Type": "StringType" }], "DocNumber": "1007", "TxnDate": "2020-03-03", "CurrencyRef": { "value": "USD", "name": "United States Dollar" }, "LinkedTxn": [{ "TxnId": "32", "TxnType": "Payment" }], "Line": [{ "Id": "1", "LineNum": 1, "Description": "Custom Design", "Amount": 750, "DetailType": "SalesItemLineDetail", "SalesItemLineDetail": { "ItemRef": { "value": "4", "name": "Design" }, "UnitPrice": 75, "Qty": 10, "TaxCodeRef": { "value": "NON" } } }, { "Amount": 750, "DetailType": "SubTotalLineDetail", "SubTotalLineDetail": {} } ], "TxnTaxDetail": { "TotalTax": 0 }, "CustomerRef": { "value": "13", "name": "uiool" }, "CustomerMemo": { "value": "Thank you for your business and have a great day!" }, "SalesTermRef": { "value": "3" }, "DueDate": "2020-04-02", "TotalAmt": 750, "ApplyTaxAfterDiscount": false, "PrintStatus": "NeedToPrint", "EmailStatus": "NotSet", "BillEmail": { "Address": "uiikoool" }, "Balance": 450 }

const result = getSchema(invoiceObject)

console.log(result)

<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.15/lodash.js"></script>

Without lodash, the main change is to use Object.entries() to get an array of [key, value] pairs, since Array.flatMap() can't iterate objects:

const getSchema = (val, keys = []) =>
  typeof val === 'object' && val !== null ? // if it's an object or array
    Object.entries(val) // get [key, value] pairs of object/array
      .flatMap(([k, v]) => getSchema(v, [...keys, k])) // iterate it and call fn with the value and the collected keys 
    :
    keys.join('.') // return the joined keys

const invoiceObject = { "AllowIPNPayment": false, "AllowOnlinePayment": false, "AllowOnlineCreditCardPayment": false, "AllowOnlineACHPayment": false, "domain": "QBO", "sparse": false, "Id": "16", "SyncToken": "1", "MetaData": { "CreateTime": "2020-03-25T15:10:40-07:00", "LastUpdatedTime": "2020-03-26T11:06:49-07:00" }, "CustomField": [{ "DefinitionId": "1", "Name": "Crew #", "Type": "StringType" }], "DocNumber": "1007", "TxnDate": "2020-03-03", "CurrencyRef": { "value": "USD", "name": "United States Dollar" }, "LinkedTxn": [{ "TxnId": "32", "TxnType": "Payment" }], "Line": [{ "Id": "1", "LineNum": 1, "Description": "Custom Design", "Amount": 750, "DetailType": "SalesItemLineDetail", "SalesItemLineDetail": { "ItemRef": { "value": "4", "name": "Design" }, "UnitPrice": 75, "Qty": 10, "TaxCodeRef": { "value": "NON" } } }, { "Amount": 750, "DetailType": "SubTotalLineDetail", "SubTotalLineDetail": {} } ], "TxnTaxDetail": { "TotalTax": 0 }, "CustomerRef": { "value": "13", "name": "uiool" }, "CustomerMemo": { "value": "Thank you for your business and have a great day!" }, "SalesTermRef": { "value": "3" }, "DueDate": "2020-04-02", "TotalAmt": 750, "ApplyTaxAfterDiscount": false, "PrintStatus": "NeedToPrint", "EmailStatus": "NotSet", "BillEmail": { "Address": "uiikoool" }, "Balance": 450 }

const result = getSchema(invoiceObject)

console.log(result)

Answer 2

You could solve this with a recursive function. The function below keeps track of the current keys, and joins them as soon as an end point is reached (a non-object or empty object/array).

const invoiceObject = { "AllowIPNPayment": false, "AllowOnlinePayment": false, "AllowOnlineCreditCardPayment": false, "AllowOnlineACHPayment": false, "domain": "QBO", "sparse": false, "Id": "16", "SyncToken": "1", "MetaData": { "CreateTime": "2020-03-25T15:10:40-07:00", "LastUpdatedTime": "2020-03-26T11:06:49-07:00" }, "CustomField": [{ "DefinitionId": "1", "Name": "Crew #", "Type": "StringType" }], "DocNumber": "1007", "TxnDate": "2020-03-03", "CurrencyRef": { "value": "USD", "name": "United States Dollar" }, "LinkedTxn": [{ "TxnId": "32", "TxnType": "Payment" }], "Line": [{ "Id": "1", "LineNum": 1, "Description": "Custom Design", "Amount": 750, "DetailType": "SalesItemLineDetail", "SalesItemLineDetail": { "ItemRef": { "value": "4", "name": "Design" }, "UnitPrice": 75, "Qty": 10, "TaxCodeRef": { "value": "NON" } } }, { "Amount": 750, "DetailType": "SubTotalLineDetail", "SubTotalLineDetail": {} } ], "TxnTaxDetail": { "TotalTax": 0 }, "CustomerRef": { "value": "13", "name": "uiool" }, "CustomerMemo": { "value": "Thank you for your business and have a great day!" }, "SalesTermRef": { "value": "3" }, "DueDate": "2020-04-02", "TotalAmt": 750, "ApplyTaxAfterDiscount": false, "PrintStatus": "NeedToPrint", "EmailStatus": "NotSet", "BillEmail": { "Address": "uiikoool" }, "Balance": 450 };

function getDotKeys(item, keys = []) {
  const isObject = item && typeof item == "object";
  if (!isObject) return Array.of(keys.join("."));

  const pairs = Array.isArray(item)
    ? item.map((value, index) => [index, value])
    : Object.entries(item);

  const isEmpty = !pairs.length;
  if (isEmpty) return Array.of(keys.join("."));

  const result = [];
  for (const [key, value] of pairs) {
    const dotKeys = getDotKeys(value, [...keys, key]);
    result.push(...dotKeys);
  }
  return result;
}

console.log(getDotKeys(invoiceObject));

This does produce a different result than what you have in your question, since your solution stops at the second level for objects and third level for arrays. This solution also includes more then only index 0.

Answer 3

inspired by the answer given in this post and understanding you just want to get the property-names, not values, you could do it like this. sorry, this uses plain javascript.

function flattenObjectToKeyArray(ob) {
  var toReturn = [];
  for (var prop in ob) {
    if (!ob.hasOwnProperty(prop)) continue;

    if ((typeof ob[prop]) == 'object' && ob[prop] !== null) {
      var flatObject = flattenObjectToKeyArray(ob[prop]);
      for (var idx = 0; idx < flatObject.length; idx++) {
        toReturn.push(prop + '.' + flatObject[idx]);
      }
    } else {
      toReturn.push(prop);
    }
  }
  return toReturn;
}