Update only some part of JSON data without cleaning the report

Data source

HTML

<link rel="stylesheet" href="https://cdn.flexmonster.com/2.3/demo.css">
<script src="https://cdn.flexmonster.com/flexmonster.js"></script>

<div>
  <h2>How to update only some part of JSON data without cleaning the report</h2>
  <p>
  The <a href="https://www.flexmonster.com/api/updatedata/" target="_blank">updateData()</a> method allows updating the data whereas other report configurations are not changed. 
  </p>
  <p>
  For JSON, <code>updateData()</code> supports partial data update. This example shows how to add, edit, and delete records in your dataset.
  </p>
  <p>
  <a href="https://www.flexmonster.com/api/updatedata/#!example-4" target="_blank">Visit our docs to learn more about partial data update</a>.
  </p>
</div>


<div id="pivot-container"></div>

CSS

h2 {
  text-align: center;
}

p {
  font-size: 15px;
  line-height: 1.5;
  padding-right: 10px;
  padding-left: 10px;
}

a {
  color: #00a45a;
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

code {
    font-size: 105%;
    color: #DF3800;
    background-color: #f5f5f5;
    padding: 1px 4px;
    font-family: monospace !important;
    border-radius: 4px;
}

JavaScript

let pivot = new Flexmonster({
  container: "pivot-container",
  componentFolder: "https://cdn.flexmonster.com/",
  width: "100%",
  height: 430,
  report: {
    dataSource: {
      data: getData()
    },
    "slice": {
      "rows": [{
          "uniqueName": "symbol"
        },
        {
          "uniqueName": "UL"
        }
      ],
      "columns": [{
        "uniqueName": "[Measures]"
      }],
      "measures": [{
          "uniqueName": "Qty",
          "aggregation": "sum"
        },
        {
          "uniqueName": "Net PnL",
          "aggregation": "sum"
        },
        {
          "uniqueName": "Cumul Pnl",
          "aggregation": "sum"
        },
        {
          "uniqueName": "Trade PnL",
          "aggregation": "sum"
        },
        {
          "uniqueName": "price",
          "aggregation": "sum"
        },
        {
          "uniqueName": "delta",
          "aggregation": "sum"
        },
        {
          "uniqueName": "gamma",
          "aggregation": "sum"
        },
        {
          "uniqueName": "Dollar Delta",
          "aggregation": "sum"
        },
        {
          "uniqueName": "Dollar Gamma",
          "aggregation": "sum"
        },
        {
          "uniqueName": "vega",
          "aggregation": "sum"
        },
        {
          "uniqueName": "Weighted Vega",
          "aggregation": "sum"
        },
        {
          "uniqueName": "VIX Vega",
          "aggregation": "sum"
        },
        {
          "uniqueName": "theta",
          "aggregation": "sum"
        },
        {
          "uniqueName": "vanna",
          "aggregation": "sum"
        },
        {
          "uniqueName": "volga",
          "aggregation": "sum"
        },
        {
          "uniqueName": "Vol",
          "aggregation": "average"
        },
        {
          "uniqueName": "YDay Vol",
          "aggregation": "average"
        },
      ]
    },
  }
});


function getData() {
  return [{
    "symbol": "SPX 2021-12-17 FUT",
   ...