Automatically Sizing Text in D3

<!DOCTYPE html>
<style> body { font-family: sans-serif; } </style>
<script src="https://cdn.jsdelivr.net/npm/d3@12.10.3/d3.min.js"></script>
<script src="https://cdn.jsdelivr.net/npm/d3@12.10.3/d3.layout.min.js"></script>
<div id="chart"></div>
<script>
var r = 960,
    format = d3.format(",d"),
    fill = d3.scale.category20c();

var bubble = d3.layout.pack()
    .sort(null)
    .size([r, r]);

var vis = d3.select("#chart").append("svg")
    .attr("width", r)
    .attr("height", r)
    .attr("class", "bubble");

d3.json("flare.json", function(err, json) {
  var node = vis.selectAll("g.node")
      .data(bubble.nodes(classes(json))
      .filter(function(d) { return !d.children; }))
    .enter().append("g")
      .attr("class", "node")
      .attr("transform", function(d) { return "translate(" + d.x + "," + d.y + ")"; });

node.append("title")
      .text(function(d) { return d.className + ": " + format(d.value); });

node.append("circle")
      .attr("r", function(d) { return d.r; })
      .style("fill", function(d) { return fill(d.packageName); });

node.append("text")
      .attr("text-anchor", "middle")
      .attr("dy", ".3em")
      .text(function(d) { return d.className; })
      .each(function(d) {
        var rect,
            r2 = d.r * d.r,
            s = d.r * 2,
            t = d3.select(this);
        do {
          t.style("font-size", s-- + "px");
          rect = this.getBBox();
        } while (norm2(rect.x, rect.y) > r2
          || norm2(rect.x + rect.width, rect.y) > r2
          || norm2(rect.x + rect.width, rect.y + rect.height) > r2
          || norm2(rect.x, rect.y + rect.height) > r2);
      });
});

function norm2(x, y) {
  return x * x + y * y;
}

// Returns a flattened hierarchy containing all leaf nodes under the root.
function classes(root) {
  var classes = [];

recurse(null, root);
  return {children: classes};
}
</script>

Modified http://mbostock.github.com/d3/d3.min.js to a secure url

Modified http://mbostock.github.com/d3/d3.layout.min.js to a secure url

https://mbostock.github.com/d3/d3.min.js

https://mbostock.github.com/d3/d3.layout.min.js