bar-chart.js

d3.chart("BarChart", {

  initialize: function(options) {

    options = options || {};

    var chart = this;

    this.x = d3.scale.linear();

    this.y = d3.scale.linear()
      .domain([0, 100]);

    this.base
      .attr("class", "chart");

    function onEnter() {
      var length = this.data().length;
      this.attr("x", function(d, i) { return chart.x(i + 1) - .5; })
          .attr("y", function(d) { return chart.h - chart.y(d.value) - .5; })
          .attr("width", chart.width() / length)
          .attr("height", function(d) { return chart.y(d.value); });
    }

    function onEnterTrans() {
      this.duration(1000)
          .attr("x", function(d, i) { return chart.x(i) - .5; });
    }

    function onTrans() {
      this.duration(1000)
          .attr("x", function(d, i) { return chart.x(i) - .5; });
    }

    function onExitTrans() {
      this.duration(1000)
          .attr("x", function(d, i) { return chart.x(i - 1) - .5; });
    }

    function dataBind(data) {

      return this.selectAll("rect")
        .data(data, function(d) { return d.time; });
    }

    function insert() {
      return this.insert("rect", "line");
    }

    this.layer("bars", this.base.append("g"), {
      dataBind: dataBind,
      insert: insert
    });

    this.layer("bars").on("enter", onEnter);
    this.layer("bars").on("enter:transition", onEnterTrans);
    this.layer("bars").on("update:transition", onTrans);
    this.layer("bars").on("exit:transition", onExitTrans);
    this.width(options.width || 600);
    this.height(options.height || 80);

  },

  width: function(newWidth) {
    if (!arguments.length) {
      return this.w;
    }
    this.w = newWidth;
    this.x.range([0, this.w]);
    this.base.attr("width", this.w);
    return this;
  },

  height: function(newHeight) {
    if (!arguments.length) {
      return this.h;
    }
    this.h = newHeight;
    this.y.rangeRound([0, this.h]);
    this.base.attr("height", this.h);
    return this;
  },

  transform: function(data) {
    this.x.domain([0, data.length]);
    return data;
  }

});