Collapsible Indented Tree

<!DOCTYPE html>
<meta charset="utf-8">
<style>

.node rect {
  cursor: pointer;
  fill: #fff;
  fill-opacity: .5;
  stroke: #3182bd;
  stroke-width: 1.5px;
}

.node text {
  font: 10px sans-serif;
  pointer-events: none;
}

path.link {
  fill: none;
  stroke: #9ecae1;
  stroke-width: 1.5px;
}

</style>
<body>
<script src="//d3js.org/d3.v3.min.js"></script>
<script>

var margin = {top: 30, right: 20, bottom: 30, left: 20},
    width = 960 - margin.left - margin.right,
    barHeight = 20,
    barWidth = width * .8;

var i = 0,
    duration = 400,
    root;

var tree = d3.layout.tree()
    .nodeSize([0, 20]);

var diagonal = d3.svg.diagonal()
    .projection(function(d) { return [d.y, d.x]; });

var svg = d3.select("body").append("svg")
    .attr("width", width + margin.left + margin.right)
  .append("g")
    .attr("transform", "translate(" + margin.left + "," + margin.top + ")");

d3.json("flare.json", function(error, flare) {
  if (error) throw error;

flare.x0 = 0;
  flare.y0 = 0;
  update(root = flare);
});

function update(source) {

// Compute the flattened node list. TODO use d3.layout.hierarchy.
  var nodes = tree.nodes(root);

var height = Math.max(500, nodes.length * barHeight + margin.top + margin.bottom);

d3.select("svg").transition()
      .duration(duration)
      .attr("height", height);

d3.select(self.frameElement).transition()
      .duration(duration)
      .style("height", height + "px");

// Compute the "layout".
  nodes.forEach(function(n, i) {
    n.x = i * barHeight;
  });

// Update the nodes…
  var node = svg.selectAll("g.node")
      .data(nodes, function(d) { return d.id || (d.id = ++i); });

var nodeEnter = node.enter().append("g")
      .attr("class", "node")
      .attr("transform", function(d) { return "translate(" + source.y0 + "," + source.x0 + ")"; })
      .style("opacity", 1e-6);

// Enter any new nodes at the parent's previous position.
  nodeEnter.append("rect")
      .attr("y", -barHeight / 2)
      .attr("height", barHeight)
      .attr("width", barWidth)
      .style("fill", color)
      .on("click", click);

nodeEnter.append("text")
      .attr("dy", 3.5)
      .attr("dx", 5.5)
      .text(function(d) { return d.name; });

// Transition nodes to their new position.
  nodeEnter.transition()
      .duration(duration)
      .attr("transform", function(d) { return "translate(" + d.y + "," + d.x + ")"; })
      .style("opacity", 1);

node.transition()
      .duration(duration)
      .attr("transform", function(d) { return "translate(" + d.y + "," + d.x + ")"; })
      .style("opacity", 1)
    .select("rect")
      .style("fill", color);

// Transition exiting nodes to the parent's new position.
  node.exit().transition()
      .duration(duration)
      .attr("transform", function(d) { return "translate(" + source.y + "," + source.x + ")"; })
      .style("opacity", 1e-6)
      .remove();

// Update the links…
  var link = svg.selectAll("path.link")
      .data(tree.links(nodes), function(d) { return d.target.id; });

// Enter any new links at the parent's previous position.
  link.enter().insert("path", "g")
      .attr("class", "link")
      .attr("d", function(d) {
        var o = {x: source.x0, y: source.y0};
        return diagonal({source: o, target: o});
      })
    .transition()
      .duration(duration)
      .attr("d", diagonal);

// Transition links to their new position.
  link.transition()
      .duration(duration)
      .attr("d", diagonal);

// Transition exiting nodes to the parent's new position.
  link.exit().transition()
      .duration(duration)
      .attr("d", function(d) {
        var o = {x: source.x, y: source.y};
        return diagonal({source: o, target: o});
      })
      .remove();

// Stash the old positions for transition.
  nodes.forEach(function(d) {
    d.x0 = d.x;
    d.y0 = d.y;
  });
}

// Toggle children on click.
function click(d) {
  if (d.children) {
    d._children = d.children;
    d.children = null;
  } else {
    d.children = d._children;
    d._children = null;
  }
  update(d);
}

function color(d) {
  return d._children ? "#3182bd" : d.children ? "#c6dbef" : "#fd8d3c";
}

</script>

https://d3js.org/d3.v3.min.js