text: /* ------------------------------------------------------------------------------
   *
   *  # D3.js - line chart with chained transitions
   *
   *  Demo d3.js line chart setup with chained transitions and .tsv data source
   *
   * ---------------------------------------------------------------------------- */
  
  
  // Setup module
  // ------------------------------
  
  var D3ChainedTransitions = function() {
  
  
      //
      // Setup module components
      //
  
      // Chart
      var _lineTransitions = function() {
          if (typeof d3 == 'undefined') {
              console.warn('Warning - d3.min.js is not loaded.');
              return;
          }
  
          // Main variables
          var element = document.getElementById('d3-chained-transitions'),
              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: 90, bottom: 20, left: 40},
                  width = d3Container.node().getBoundingClientRect().width - margin.left - margin.right,
                  height = height - margin.top - margin.bottom - 5;
  
  
              // City name
              var city = "New York";
  
              // Format data
              parseDate = d3.time.format("%Y%m%d").parse;
  
              // Color
              var color = '#b6a2de';
  
  
  
              // Construct scales
              // ------------------------------
  
              // Horizontal
              var x = d3.time.scale()
                  .range([0, width]);
  
              // Vertical
              var y = d3.scale.linear()
                  .range([height, 0]);
  
  
  
              // Create axes
              // ------------------------------
  
              // Horizontal
              var xAxis = d3.svg.axis()
                  .scale(x)
                  .orient("bottom")
                  .ticks(6)
                  .tickFormat(d3.time.format("%b"));
  
              // Vertical
              var yAxis = d3.svg.axis()
                  .scale(y)
                  .orient("left");
  
  
  
              // 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
              // ------------------------------
  
              // Line
              var line = d3.svg.line()
                  .interpolate("basis")
                  .x(function(d) { return x(d.date); })
                  .y(function(d) { return y(d[city]); });
  
  
  
              // Load data
              // ------------------------------
  
              d3.tsv("../../demo_data/d3/lines/lines_transitions.tsv", function(error, data) {
  
                  // Pull out values
                  data.forEach(function(d) {
                      d.date = parseDate(d.date);
                      d["New York"] = +d["New York"];
                      d["San Francisco"] = +d["San Francisco"];
                  });
  
  
                  // Set input domains
                  // ------------------------------
  
                  // Horizontal
                  x.domain([data[0].date, data[data.length - 1].date]);
  
                  // Vertical
                  y.domain(d3.extent(data, function(d) { return d[city]; }));
  
  
                  //
                  // Append chart elements
                  //
  
                  // Add line
                  svg.append("path")
                      .datum(data)
                      .attr("d", line)
                      .attr("class", "d3-line d3-line-medium")
                      .style("stroke", color);
  
  
                  // Add text
                  svg.append("text")
                      .datum(data[data.length - 1])
                      .attr("class", "d3-city d3-text")
                      .attr("transform", transform)
                      .attr("x", 3)
                      .attr("dy", ".35em")
                      .text(city);
  
  
                  // Append axes
                  // ------------------------------
  
                  // Horizontal
                  svg.append("g")
                      .attr("class", "d3-axis d3-axis-horizontal")
                      .attr("transform", "translate(0," + height + ")")
                      .call(xAxis);
  
                  // Vertical
                  var verticalAxis = svg.append("g")
                      .attr("class", "d3-axis d3-axis-vertical")
                      .call(yAxis);
  
                  // Add text label
                  verticalAxis.append("text")
                      .attr("class", "d3-axis-title")
                      .attr("transform", "rotate(-90)")
                      .attr("y", 10)
                      .attr("dy", ".71em")
                      .style("text-anchor", "end")
                      .text("Temperature (ºF)");
  
  
                  // Transitions
                  // ------------------------------
  
                  // Do stuff on value change
                  d3.selectAll(".d3-transitions-control").on("change", change);
  
                  // Set timeout for auto change
                  var timeout = setTimeout(function() {
                      d3.select("input[value=\"San Francisco\"]").property("checked", true).each(change);
                  }, 3000);
  
                  // Change function
                  function change() {
                      clearTimeout(timeout);
                      city = this.value;
  
                      // First transition the line & label to the new city.
                      var t0 = svg.transition().duration(750);
                      t0.selectAll(".d3-line").attr("d", line);
                      t0.selectAll(".d3-city").attr("transform", transform).text(city);
  
                      // Then transition the y-axis.
                      y.domain(d3.extent(data, function(d) { return d[city]; }));
                      var t1 = t0.transition();
                      t1.selectAll(".d3-line").attr("d", line);
                      t1.selectAll(".d3-city").attr("transform", transform);
                      t1.selectAll(".d3-axis-vertical").call(yAxis);
                  }
  
                  // Transform text
                  function transform(d) {
                      return "translate(" + x(d.date) + "," + y(d[city]) + ")";
                  }
  
  
  
                  // Resize chart
                  // ------------------------------
  
                  // Call function on window resize
                  window.addEventListener('resize', resize);
  
                  // Call function on sidebar width change
                  var sidebarToggle = document.querySelector('.sidebar-control');
                  sidebarToggle && sidebarToggle.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.range([0, width]);
  
                      // Horizontal axis
                      svg.selectAll('.d3-axis-horizontal').call(xAxis);
  
  
                      // Chart elements
                      // -------------------------
  
                      // Line path
                      svg.selectAll('.d3-line').attr("d", line);
  
                      // Text
                      svg.selectAll(".d3-city").attr("transform", transform);
                  }
              });
          }
      };
  
  
      //
      // Return objects assigned to module
      //
  
      return {
          init: function() {
              _lineTransitions();
          }
      }
  }();
  
  
  // Initialize module
  // ------------------------------
  
  document.addEventListener('DOMContentLoaded', function() {
      D3ChainedTransitions.init();
  });
  