text: /* ------------------------------------------------------------------------------
   *
   *  # D3.js - stacked and multiple bars
   *
   *  Demo d3.js bar chart setup with animated transition between stacked and multiple bars
   *
   * ---------------------------------------------------------------------------- */
  
  
  // Setup module
  // ------------------------------
  
  var D3BarStackedMultiple = function () {
  
  
      //
      // Setup module components
      //
  
      // Chart
      var _barStackedMultiple = function () {
          if (typeof d3 == 'undefined') {
              console.warn('Warning - d3.min.js is not loaded.');
              return;
          }
  
          // Main variables
          var element = document.getElementById('d3-bar-stacked-multiples'),
              height = 400;
  
  
          // Initialize chart only if element exsists in the DOM
          if (element) {
  
              // Basic setup
              // ------------------------------
  
              // Define main variables
              var d3Container = d3.select(element),
                  margin = {top: 5, right: 20, bottom: 20, left: 60},
                  width = d3Container.node().getBoundingClientRect().width - margin.left - margin.right,
                  height = height - margin.top - margin.bottom - 5;
  
              // Format data
              var parseDate = d3.time.format("%Y-%m").parse,
                  formatYear = d3.format("02d"),
                  formatDate = function (d) {
                      return "Q" + ((d.getMonth() / 3 | 0) + 1) + formatYear(d.getFullYear() % 100);
                  };
  
              // Colors
              var color = d3.scale.category20();
  
  
              // Construct scales
              // ------------------------------
  
              // Horizontal
              var x = d3.scale.ordinal()
                  .rangeRoundBands([0, width], .2);
  
              // Vertical
              var y = d3.scale.ordinal()
                  .rangeRoundBands([height, 0]);
  
              var y0 = d3.scale.ordinal()
                  .rangeRoundBands([height, 0]);
  
              var y1 = d3.scale.linear();
  
  
              // Create axes
              // ------------------------------
  
              // Horizontal
              var xAxis = d3.svg.axis()
                  .scale(x)
                  .orient("bottom")
                  .tickFormat(formatDate);
  
              // Vertical
              var yAxis = d3.svg.axis()
                  .scale(y)
                  .orient("left")
                  .ticks(10, "%");
  
  
              // Create chart
              // ------------------------------
  
              // Add SVG element
              var container = d3Container.append("svg");
  
              // Add SVG group
              var svg = container
                  .attr("width", width + margin.left + margin.right)
                  .attr("height", height + margin.top + margin.bottom)
                  .append("g")
                  .attr("transform", "translate(" + margin.left + "," + margin.top + ")");
  
  
              // Construct chart layout
              // ------------------------------
  
              // Nest
              var nest = d3.nest()
                  .key(function (d) {
                      return d.browser;
                  });
  
              // Stack
              var stack = d3.layout.stack()
                  .values(function (d) {
                      return d.values;
                  })
                  .x(function (d) {
                      return d.date;
                  })
                  .y(function (d) {
                      return d.value;
                  })
                  .out(function (d, y0) {
                      d.valueOffset = y0;
                  });
  
  
              // Load data
              // ------------------------------
  
              d3.tsv("../../../../global_assets/demo_data/d3/bars/bars_stacked_multiple.tsv", function (error, data) {
  
                  // Pull out values
                  data.forEach(function (d) {
                      d.date = parseDate(d.date);
                      d.value = +d.value;
                  });
  
                  // Nest values
                  var dataByGroup = nest.entries(data);
  
  
                  // Set input domains
                  // ------------------------------
  
                  // Stack
                  stack(dataByGroup);
  
                  // Horizontal
                  x.domain(dataByGroup[0].values.map(function (d) {
                      return d.date;
                  }));
  
                  // Vertical
                  y0.domain(dataByGroup.map(function (d) {
                      return d.key;
                  }));
                  y1.domain([0, d3.max(data, function (d) {
                      return d.value;
                  })]).range([y0.rangeBand(), 0]);
  
  
                  //
                  // Append chart elements
                  //
  
                  // Add bars
                  // ------------------------------
  
                  // Group bars
                  var group = svg.selectAll(".d3-bar-group")
                      .data(dataByGroup)
                      .enter()
                      .append("g")
                      .attr("class", "d3-bar-group")
                      .attr("transform", function (d) {
                          return "translate(0," + y0(d.key) + ")";
                      });
  
                  // Append text
                  group.append("text")
                      .attr("class", "d3-group-label d3-text")
                      .attr("x", -12)
                      .attr("y", function (d) {
                          return y1(d.values[0].value / 2);
                      })
                      .attr("dy", ".35em")
                      .style("text-anchor", "end")
                      .text(function (d) {
                          return d.key;
                      });
  
                  // Add bars
                  group.selectAll(".d3-bar")
                      .data(function (d) {
                          return d.values;
                      })
                      .enter()
                      .append("rect")
                      .attr("class", "d3-bar")
                      .attr("x", function (d) {
                          return x(d.date);
                      })
                      .attr("y", function (d) {
                          return y1(d.value);
                      })
                      .attr("width", x.rangeBand())
                      .attr("height", function (d) {
                          return y0.rangeBand() - y1(d.value);
                      })
                      .style("fill", function (d) {
                          return color(d.browser);
                      });
  
  
                  // Append axes
                  // ------------------------------
  
                  // Horizontal
                  group.filter(function (d, i) {
                      return !i;
                  }).append("g")
                      .attr("class", "d3-axis d3-axis-horizontal")
                      .attr("transform", "translate(0," + (y0.rangeBand() + 1) + ")")
                      .call(xAxis);
  
                  // Vertical
                  var verticalAxis = svg.append("g")
                      .attr("class", "d3-axis d3-axis-vertical")
                      .call(yAxis);
  
                  // Appent text label
                  verticalAxis.append("text")
                      .attr('class', 'd3-axis-title browser-label')
                      .attr("x", -12)
                      .attr("y", 12)
                      .attr("dy", ".71em")
                      .style("text-anchor", "end")
                      .text("Browser");
  
  
                  // Setup layout change
                  // ------------------------------
  
                  // Add change event
                  d3.selectAll(".stacked-multiple").on("change", change);
  
                  // Change value on page load
                  var timeout = setTimeout(function () {
                      d3.selectAll("input[value=\"stacked\"]").property("checked", true).each(change);
                  }, 2000);
  
                  // Change function
                  function change() {
                      clearTimeout(timeout);
                      if (this.value === "multiples") transitionMultiples();
                      else transitionStacked();
                  }
  
                  // Transition to multiples
                  function transitionMultiples() {
                      var t = svg.transition().duration(750),
                          g = t.selectAll(".d3-bar-group").attr("transform", function (d) {
                              return "translate(0," + y0(d.key) + ")";
                          });
                      g.selectAll(".d3-bar").attr("y", function (d) {
                          return y1(d.value);
                      });
                      g.select(".d3-group-label").attr("y", function (d) {
                          return y1(d.values[0].value / 2);
                      })
                  }
  
                  // Transition to stacked
                  function transitionStacked() {
                      var t = svg.transition().duration(750),
                          g = t.selectAll(".d3-bar-group").attr("transform", "translate(0," + y0(y0.domain()[0]) + ")");
                      g.selectAll(".d3-bar").attr("y", function (d) {
                          return y1(d.value + d.valueOffset)
                      });
                      g.select(".d3-group-label").attr("y", function (d) {
                          return y1(d.values[0].value / 2 + d.values[0].valueOffset);
                      })
                  }
              });
  
  
              // Resize chart
              // ------------------------------
  
              // Call function on window resize
              window.addEventListener('resize', resize);
  
              // Call function on sidebar width change
              var sidebarToggle = document.querySelectorAll('.sidebar-control');
              if (sidebarToggle) {
                  sidebarToggle.forEach(function (togglers) {
                      togglers.addEventListener('click', resize);
                  });
              }
  
              // Resize function
              // 
              // Since D3 doesn't support SVG resize by default,
              // we need to manually specify parts of the graph that need to 
              // be updated on window resize
              function resize() {
  
                  // Layout variables
                  width = d3Container.node().getBoundingClientRect().width - margin.left - margin.right;
  
  
                  // Layout
                  // -------------------------
  
                  // Main svg width
                  container.attr("width", width + margin.left + margin.right);
  
                  // Width of appended group
                  svg.attr("width", width + margin.left + margin.right);
  
  
                  // Axes
                  // -------------------------
  
                  // Horizontal range
                  x.rangeRoundBands([0, width], .2);
  
                  // Horizontal axis
                  svg.selectAll('.d3-axis-horizontal').call(xAxis);
  
  
                  // Chart elements
                  // -------------------------
  
                  // Line path
                  svg.selectAll('.d3-bar').attr("x", function (d) {
                      return x(d.date);
                  }).attr("width", x.rangeBand());
              }
          }
      };
  
  
      //
      // Return objects assigned to module
      //
  
      return {
          init: function () {
              _barStackedMultiple();
          }
      }
  }();
  
  
  // Initialize module
  // ------------------------------
  
  document.addEventListener('DOMContentLoaded', function () {
      D3BarStackedMultiple.init();
  });
  