title: D3: How do you highlight a range of dates on D3 a line chart?
body: <p>I’m building a simple line chart using D3. The chart will contain a range of dates on the X axis and a range of values on the Y axis.</p>
  
  <p>I’d like to draw a couple of rectangles behind the line. These rect’s would span the height of the chart and span the width of the dates that I would define. Let’s say for example rect 1 being between Thu 18th to Wed 24th and rect 2 being between Wed 24th and Tue 30th.</p>
  
  <p>These rect’s would also have a click event attached to them. So that if clicked, they would trigger a function that I would define. This function would need to know which rect was clicked.</p>
  
  <p>Has anybody achieved something like this before? Can anybody help steer me in the right direction? Thanks so much.</p>
  
  <p><strong>I've created this Fiddle to get started (based on an mbostock example):</strong></p>
  
  <p><a href="http://jsfiddle.net/Critter/TJqE6/2/" rel="nofollow">http://jsfiddle.net/Critter/TJqE6/2/</a></p>
  
  <pre><code>var data = [
    {"date":"1-May-13","close":58.13},
    {"date":"30-Apr-13","close":53.98},
    {"date":"27-Apr-13","close":67.00},
    {"date":"26-Apr-13","close":89.70},
    {"date":"25-Apr-13","close":99.00},
    {"date":"24-Apr-13","close":130.28},
    {"date":"23-Apr-13","close":166.70},
    {"date":"20-Apr-13","close":234.98},
    {"date":"19-Apr-13","close":345.44},
    {"date":"18-Apr-13","close":443.34},
  ];
  
  var margin = {top: 20, right: 50, bottom: 30, left: 50},
      width = 960 - margin.left - margin.right,
      height = 500 - margin.top - margin.bottom;
  
  var parseDate = d3.time.format("%d-%b-%y").parse,
      bisectDate = d3.bisector(function(d) { return d.date; }).left,
      formatValue = d3.format(",.2f"),
      formatCurrency = function(d) { return "$" + formatValue(d); };
  
  var x = d3.time.scale()
      .range([0, width]);
  
  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");
  
  var line = d3.svg.line()
      .x(function(d) { return x(d.date); })
      .y(function(d) { return y(d.close); });
  
  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 + ")");
  
    data.forEach(function(d) {
      d.date = parseDate(d.date);
      d.close = +d.close;
  
    data.sort(function(a, b) {
      return a.date - b.date;
    });
  
    x.domain([data[0].date, data[data.length - 1].date]);
    y.domain(d3.extent(data, function(d) { return d.close; }));
  
    svg.append("g")
        .attr("class", "x axis")
        .attr("transform", "translate(0," + height + ")")
        .call(xAxis);
  
    svg.append("g")
        .attr("class", "y axis")
        .call(yAxis)
      .append("text")
        .attr("transform", "rotate(-90)")
        .attr("y", 6)
        .attr("dy", ".71em")
        .style("text-anchor", "end")
        .text("Price ($)");
  
    svg.append("path")
        .datum(data)
        .attr("class", "line")
        .attr("d", line);
  
    var focus = svg.append("g")
        .attr("class", "focus")
        .style("display", "none");
  
    focus.append("circle")
        .attr("r", 4.5);
  
    focus.append("text")
        .attr("x", 9)
        .attr("dy", ".35em");
  
    svg.append("rect")
        .attr("class", "overlay")
        .attr("width", width)
        .attr("height", height)
        .on("mouseover", function() { focus.style("display", null); })
        .on("mouseout", function() { focus.style("display", "none"); })
        .on("mousemove", mousemove);
  
    function mousemove() {
      var x0 = x.invert(d3.mouse(this)[0]),
          i = bisectDate(data, x0, 1),
          d0 = data[i - 1],
          d1 = data[i],
          d = x0 - d0.date &gt; d1.date - x0 ? d1 : d0;
      focus.attr("transform", "translate(" + x(d.date) + "," + y(d.close) + ")");
      focus.select("text").text(formatCurrency(d.close));
    }
  });
  </code></pre>