Neighborhood highlight

Hover a node with the mouse. Its direct node neighbors become bigger and red, and neighbors or neighbors become orange.
          <!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <script src="../build/ogma.min.js"></script>
  <style>
    #graph-container { top: 0; bottom: 0; left: 0; right: 0; position: absolute; margin: 0; overflow: hidden; }
  </style>
</head>
<body>
  <div id="graph-container"></div>

<script>
'use strict';

var ogma = new Ogma({
  container: 'graph-container'
});

ogma.createClass('sourceNode');

// Create a class for 1st step neighbors
ogma.createClass('neighbor1', {
  nodeAttributes: {
    color: 'red',
    radius: 7,
    icon: {
      color: 'white',
      content: "1",
    }
  },
  edgeAttributes: {
    color: 'red'
  }
});

// Create a class for 1st step neighbors
ogma.createClass('neighbor2', {
  nodeAttributes: {
    color: 'orange',
    radius: 7,
    icon: {
      color: 'white',
      content: "2",
    }
  },
  edgeAttributes: {
    color: 'orange'
  }
});

ogma.generate.erdosRenyi({nodes:20, p:0.1}).then(function(graph) {
  ogma.setGraph(graph);
  ogma.view.locateGraph();
});

ogma.events.onHover(function (ref) {
  if (!ref.target.isNode) return;

  var node = ref.target;

  node.addClass('sourceNode');

  node.getAdjacentNodes().addClass('neighbor1');
  node.getAdjacentEdges().addClass('neighbor1');

  node.getAdjacentNodes().getAdjacentNodes().filter(function (n) { return n !== node; }).addClass('neighbor2');
  node.getAdjacentNodes().getAdjacentEdges().addClass('neighbor2');

  console.log('nodes with a distance 1 ', ogma.getNodesByClassName('neighbor1'));

});

ogma.events.onUnhover(function (ref) {
  if (!ref.target.isNode) return;

  var node = ref.target;

  node.removeClass('sourceNode');

  node.getAdjacentNodes().removeClass('neighbor1');
  node.getAdjacentEdges().removeClass('neighbor1');

  // recreate the traversal to remove the class
  node.getAdjacentNodes().getAdjacentNodes().removeClass('neighbor2');
  node.getAdjacentNodes().getAdjacentEdges().removeClass('neighbor2');

  // We can also remove the class to all nodes who belong to it
//  ogma.getNodesByClassName('neighbor2').removeClass('neighbor2');
//  ogma.getEdgesByClassName('neighbor2').removeClass('neighbor2');

});

</script>
</body>
</html>