server/src/graph.html

<!DOCTYPE html>
<html>
<body>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<script src="//d3js.org/d3.v5.min.js"></script>
<script src="https://unpkg.com/viz.js@1.8.1/viz.js" type="application/javascript"></script>
<script src="https://unpkg.com/d3-graphviz@2.6.0/build/d3-graphviz.min.js"></script>

<div id="graph" style="text-align: center; width: 100%;"></div>
<script>
	var params = new URLSearchParams(new URL(window.location).search);
	var endpoint = params.has("detailed") ? "graph" : "simple_graph";

  var transition = d3.transition("t")
                     .duration(500)
                     .ease(d3.easeLinear);

  var graphviz = d3.select("#graph").graphviz(false);

  function render() {
    var graph_data = $.ajax({
      url: endpoint,
      dataType: "text",
      success: function(data) {
        graphviz.transition(transition).renderDot(data);
      },
      error: function(e) {
        graphviz.transition(transition).renderDot('digraph {}');
      }
    });

  }

  setInterval(function() {
    render();
  }, 1000)
</script>

</body>
</html>