Adding elements to a D3 circle pack nodes

Question

I am trying to make a zoomable circle packing chart. I'd like each child circle to contain a smaller chart which would always have the same structure (i.e. 4 columns, only the heights of the bars would change).

I have tried adding a simple rect to my chart so far but the rects are not added in the circle and are statics:

JS:

  var margin = 20,
      diameter = 400;

  var color = d3.scale.linear()
      .domain([-1, 5])
      .range(["hsl(152,80%,80%)", "hsl(228,30%,40%)"])
      .interpolate(d3.interpolateHcl);

  var pack = d3.layout.pack()
      .padding(2)
      .size([diameter - margin, diameter - margin])
      .value(function(d) { return d.size; })

  var svg = d3.select(".container").append("svg")
      .attr("width", diameter)
      .attr("height", diameter)
    .append("g")
      .attr("transform", "translate(" + diameter / 2 + "," + diameter / 2 + ")");

  d3.json("flare.json", function(error, root) {
    if (error) return console.error(error);

    var focus = root,
        nodes = pack.nodes(root),
        view;

    var circle = svg.selectAll("circle")
        .data(nodes)
      .enter().append("circle")
        .attr("class", function(d) { return d.parent ? d.children ? "node" : "node node--leaf" : "node node--root"; })
        .style("fill", function(d) { return d.children ? color(d.depth) : null; })
        .on("click", function(d) { if (focus !== d) zoom(d), d3.event.stopPropagation(); });

    var text = svg.selectAll("text")
        .data(nodes)
      .enter().append("text")
        .attr("class", "label")
        .style("fill-opacity", function(d) { return d.parent === root ? 1 : 0; })
        .style("display", function(d) { return d.parent === root ? null : "none"; })
        .text(function(d) { return d.name; });


    // Adding Rect to each child circle
    var bar = svg.selectAll(".bar")
        .data(nodes)
      .enter().append("rect")
        .attr("class", "bar")
        .style("fill", function(d) { return d.children ? color(d.depth) : null; })
        .style("fill-opacity", function(d) { return d.parent === root ? 1 : 0; })
        .style("display", function(d) { return d.parent === root ? null : "none"; })
        .attr("width", 20)
        .attr("x", 100)
        .attr("height", function(d) { return 40; });

    var node = svg.selectAll("circle,text");

    d3.select(".container")
        .style("background", color(-1))
        .on("click", function() { zoom(root); });

    zoomTo([root.x, root.y, root.r * 2 + margin]);

    function zoom(d) {
      var focus0 = focus; focus = d;

      var transition = d3.transition()
          .duration(d3.event.altKey ? 7500 : 750)
          .tween("zoom", function(d) {
            var i = d3.interpolateZoom(view, [focus.x, focus.y, focus.r * 2 + margin]);
            return function(t) { zoomTo(i(t)); };
          });

      transition.selectAll("text")
        .filter(function(d) { return d.parent === focus || this.style.display === "inline"; })
          .style("fill-opacity", function(d) { return d.parent === focus ? 1 : 0; })
          .each("start", function(d) { if (d.parent === focus) this.style.display = "inline"; })
          .each("end", function(d) { if (d.parent !== focus) this.style.display = "none"; });
    }

    function zoomTo(v) {
      var k = diameter / v[2]; view = v;
      node.attr("transform", function(d) { return "translate(" + (d.x - v[0]) * k + "," + (d.y - v[1]) * k + ")"; });
      circle.attr("r", function(d) { return d.r * k; });
    }
  });

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

I have also added a plunkr: http://plnkr.co/edit/CfJqUQMISDzed2F71JpT?p=preview

How can I add this rect inside the child circles only?

Many thanks

Answer 1

Yes, zooming feature adds some difficulty.

Here is a little bit dirty example of how this can be achieved: plunkr

The key code is:

// Adding Rects to each child circle
var bar1 = svg.selectAll(".bar1")
    .data(nodes)
  .enter().append("rect")
    .attr("class", "bar1")
    .style("fill", "red")
    .style("display", function(d) { return (d.depth == 4) ? null : "none"; });
var bar2 = svg.selectAll(".bar2")
    .data(nodes)
  .enter().append("rect")
    .attr("class", "bar2")
    .style("fill", "green")
    .style("display", function(d) { return (d.depth == 4) ? null : "none"; });
var bar3 = svg.selectAll(".bar3")
    .data(nodes)
  .enter().append("rect")
    .attr("class", "bar3")
    .style("fill", "blue")
    .style("display", function(d) { return (d.depth == 4) ? null : "none"; });

and

var node = svg.selectAll("circle,text,rect");

and

  bar1.attr("y", function(d) { return -d.r/2 * k - d.r/4; })
  bar1.attr("x", function(d) { return -d.r/20 * k; })
  bar1.attr("width", function(d) { return d.r/10 * k -1; });
  bar1.attr("height", function(d) { return d.r/2 * k; });
  bar2.attr("y", function(d) { return -d.r/2 * k - d.r/4; })
  bar2.attr("x", function(d) { return -d.r/20 * k + d.r/10 * k; })
  bar2.attr("width", function(d) { return d.r/10 * k-1; });
  bar2.attr("height", function(d) { return d.r/2 * k; });
  bar3.attr("y", function(d) { return -d.r/2 * k - d.r/4; })
  bar3.attr("x", function(d) { return -d.r/20 * k - d.r/10 * k; })
  bar3.attr("width", function(d) { return d.r/10 * k-1; });
  bar3.attr("height", function(d) { return d.r/2 * k; });