jQuery addClass example

Change class name on click in jQuery

HTML

<script src="https://d3js.org/d3.v7.min.js"></script>

CSS

.node circle {
  fill: #fff;
  stroke: steelblue;
  stroke-width: 3px;
}

.node text {
  font: 12px sans-serif;
}

.link {
  fill: none;
  stroke: #ccc;
  stroke-width: 2px;
}

JavaScript

var treeData =
  {
    "name": "Top Level",
    "children": [
      { 
        "name": "Child 1",
        "children": [
          { "name": "Son of Child 1" },
          { "name": "Daughter of Child 1" }
        ]
      },
      { "name": "Child 2",
        "children": [
          { "name": "Son of Child 2" },
          { "name": "Daughter of Child 2" }
        ] }
    ]
  };

// Set the dimensions and margins of the diagram
var margin = {top: 20, right: 90, bottom: 30, left: 90},
    width = 960 - margin.left - margin.right,
    height = 500 - margin.top - margin.bottom;

// append the svg object to the body of the page
// appends a 'group' element to 'svg'
// moves the 'group' element to the top left margin
var svg = d3.select("body").append("svg")
    .attr("width", width + margin.right + margin.left)
    .attr("height", height + margin.top + margin.bottom)
  .append("g")
    .attr("transform", "translate("
          + margin.left + "," + margin.top + ")");

var i = 0,
    duration = 750,
    root;

// declares a tree layout and assigns the size
var treemap = d3.tree().size([height, width]);

// Assigns parent, children, height, depth
root = d3.hierarchy(treeData, function(d) { return d.children; });
root.x0 = height / 2;
root.y0 = 0;

// Collapse after the second level
root.children.forEach(collapse);

update(root);

// Collapse the node and all it's children
function collapse(d) {
  if(d.children) {
    d._children = d.children
    d._children.forEach(collapse)
    d.children = null
  }
}


function update(source) {

const colourScale = d3.scaleOrdinal()
.domain( [ "Parent", "Child 1", "Child 2" ] )
.range( [ "#abacab", "#b67a4e", "#5a6fbb" ] );

  // Assigns the x and y position for the nodes
  var treeData = treemap(root);

  // Compute the new tree layout.
  var nodes = treeData.descendants(),
      links = treeData.descendants().slice(1);

  // Normalize for fixed-depth.
  nodes.forEach(function(d){ d.y = d.depth * 180});

  // ****************** Nodes...