D3 Examples - Variable width bar chart with matching, data driven, variable width wordwrap

Variable width bar chart with matching, data driven, variable width wordwrap
This example, using satirical data from The Onion, demonstrates how to wrap long axis labels to fit on multiple lines.
Modified wrap to acept text wrap width as a function of data and index.
Made bar widths proportional to values.
Note: The second point is not recommended practice but serves to ilustrate the variable wrap feature!
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<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8">
    <title>Wrapping Long Labels</title>
    <style>
​
      .bar {
        fill: steelblue;
      }
​
      .bar:hover {
        fill: brown;
      }
​
      .title {
        font: bold 14px "Helvetica Neue", Helvetica, Arial, sans-serif;
      }
​
      .axis {
        font: 10px sans-serif;
      }
​
      .axis path,
      .axis line {
        fill: none;
        stroke: #000;
        shape-rendering: crispEdges;
      }
​
      .x.axis path {
        display: none;
      }
​
    </style>
  </head>
  <body>
    <script src="https://cdnjs.cloudflare.com/ajax/libs/d3/3.5.5/d3.min.js"></script>
    <script>
​
      var margin = {top: 80, right: 180, bottom: 80, left: 180},
        width = 960 - margin.left - margin.right,
        height = 500 - margin.top - margin.bottom;
​
      var padding = 0.1, outerPadding = 0.3,
        x = d3.scale.ordinal()
          .rangeRoundBands([0, width], padding, outerPadding);
​
      var y = d3.scale.linear()
        .range([height, 0]);
​
      var xAxis = d3.svg.axis()
        .scale(x)
        .orient("bottom");
​
      var yAxis = d3.svg.axis()
        .scale(y)
        .orient("left")
        .ticks(8, "%");
​
      var svg = d3.select("body").append("svg")
        .attr("width", width + margin.left + margin.right)
        .attr("height", height + margin.top + margin.bottom)
        .append("g")
        .attr("transform", "translate(" + margin.left + "," + margin.top + ")");
​
      d3.tsv("data.tsv", type, function (error, data) {
        var a = alpha(data, v),   //scale factor between value and bar width
          mid = Midi(data, v, a),   //mid-point displacement of bar i
          w = Wi(data, v, a);         //width of bar i
​
        x.range(data.map(mid)); //force irregular intervals based on value
​
        x.domain(data.map(function (d) {
          return d.name;
        }));
        y.domain([0, d3.max(data, v)]);
​
        svg.append("text")
          .attr("class", "title")
          .attr("x", x(data[0].name))
          .attr("y", -26)
          .attr("shape-rendering", "crispEdges")
          .text("Why Are We Leaving Facebook?");
​
        svg.append("g")
          .attr("class", "x axis")
          .attr("transform", "translate(0," + height + ")")
          .call(xAxis)
          .selectAll(".tick text")
          .call(wrap, function (d, i) {
            return w(i);
          });
​
        svg.append("g")
          .attr("class", "y axis")
          .call(yAxis);
​
        svg.selectAll(".bar")
          .data(data)
          .enter().append("rect")
          .attr("class", "bar")
          .attr("x", function (d, i) {
            return x(d.name) - a * d.value/2;   //center the bar on the tick
          })
          //using x.range sets x.rangeBands to zero, compute width as a function of value
          .attr("width", x.rangeBand() || function (d) {
            return a * d.value; //`a` already accounts for both types of padding
          })
          .attr("y", function (d) {
            return y(d.value);
          })
          .attr("height", function (d) {
            return height - y(d.value);
          });
      });
​
      function wrap(text, width) {
        text.each(function (d, i) {
          var text = d3.select(this),
            words = text.html(d).text().split(/\s+/).reverse(), //reset html to clear any tspans added before
            word,
            line = [],
            lineNumber = 0,
            lineHeight = 1.1, // ems
            y = text.attr("y"),
            dy = parseFloat(text.attr("dy")),
            tspan = text.text(null).append("tspan").attr("x", 0).attr("y", y).attr("dy", dy + "em"),
          //[edit]add dWidth
            dWidth = typeof width === "function" ? width(d, i) : width;
          while (word = words.pop()) {
            line.push(word);
            tspan.text(line.join(" "));
            if (tspan.node().getComputedTextLength() > dWidth/*[edit]*/) {
              line.pop();
              tspan.text(line.join(" "));
              line = [word];
              tspan = text.append("tspan").attr("x", 0).attr("y", y).attr("dy", ++lineNumber * lineHeight + dy + "em").text(word);
            }
          }
        });
      }
​
      function type(d) {
        d.value = +d.value;
        return d;
      }
      function v(d) {
        return +d.value;
      }
      function alpha(values, value) {
        var n = values.length, total = d3.sum(values, value);
        return (width - (n - 1) * padding * width / n - 2 * outerPadding * width / n) / total
      }
      function Wi(values, value, alpha) {
        return function (i) {
          return value(values[i]) * alpha
        }
      }
      function Midi(values, value, alpha) {
        var w = Wi(values, value, alpha), n = values.length;
        return function (_, i) {
          var op = outerPadding * width / n, p = padding * width / n;
          return op + d3.sum(values.slice(0, i), value) * alpha + i * p + w(i) / 2;
        }
      }
    </script>
  </body>
</html>
    