D3 Examples - d3js clickable, sortable stacked bar chart

d3js clickable, sortable stacked bar chart
Stacked bar chart with a clickable legend to display one class of bars at a time, with the option of sorting them afterwards.
Note: my version fixes a small inaccuracy in Mike Bostock's original code in which the heights and y-position of the bars are not calculated directly from the data value, but on the difference between the cumulative values in the stacked bar. This inaccuracy, which is usually only around 1 pixel, is not noticeable until a single category is sorted and you can see all the bars side by side in decreasing order.
My fix is a crude hack but it works!
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<!DOCTYPE html>
<meta charset="utf-8">
<style>
​
body {
  font: 10px sans-serif;
}
​
.axis path,
.axis line {
  fill: none;
  stroke: #000;
  shape-rendering: crispEdges;
}
​
.bar {
  fill: steelblue;
}
​
.x.axis path {
  display: none;
}
​
.tooltip{
  text-anchor: middle;
  font-family: sans-serif;
  font-size: 10px;
  font-weight: bold;
  fill:black; 
}
​
label {
  position: absolute;
  top: 222px;
  right: 35px;
  color: #D8D8D8;
}
​
</style>
<body>
  <label><input type="checkbox"> Sort values</label>
​
<script src="https://d3js.org/d3.v3.min.js"></script>
<script>
​
var margin = {top: 20, right: 20, bottom: 30, left: 40},
    width = 960 - margin.left - margin.right,
    height = 500 - margin.top - margin.bottom;
​
var x = d3.scale.ordinal()
    .rangeRoundBands([0, width], .1);
​
var y = d3.scale.linear()
    .rangeRound([height, 0]);
​
var color = d3.scale.ordinal()
    .range(["#98abc5", "#8a89a6", "#7b6888", "#6b486b", "#a05d56", "#d0743c", "#ff8c00"]);
​
var xAxis = d3.svg.axis()
    .scale(x)
    .orient("bottom");
​
var yAxis = d3.svg.axis()
    .scale(y)
    .orient("left")
    .tickFormat(d3.format(".2s"));
​
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 + ")");
​
var active_link = "0"; //to control legend selections and hover
var legendClicked; //to control legend selections
var legendClassArray = []; //store legend classes to select bars in plotSingle()
var legendClassArray_orig = []; //orig (with spaces)
var sortDescending; //if true, bars are sorted by height in descending order
var restoreXFlag = false; //restore order of bars back to original
​
​
//disable sort checkbox
d3.select("label")             
  .select("input")
  .property("disabled", true)
  .property("checked", false); 
​
d3.csv("state_data.csv", function(error, data) {
  if (error) throw error;
​
  color.domain(d3.keys(data[0]).filter(function(key) { return key !== "State"; }));
​
  data.forEach(function(d) {
    var mystate = d.State; //add to stock code
    var y0 = 0;
    //d.ages = color.domain().map(function(name) { return {name: name, y0: y0, y1: y0 += +d[name]}; });
    d.ages = color.domain().map(function(name) {
      //return { mystate:mystate, name: name, y0: y0, y1: y0 += +d[name]}; });
      return { 
        mystate:mystate, 
        name: name, 
        y0: y0, 
        y1: y0 += +d[name], 
        value: d[name],
        y_corrected: 0
      }; 
      });
    d.total = d.ages[d.ages.length - 1].y1;    
​
  });
​
  //Sort totals in descending order
  data.sort(function(a, b) { return b.total - a.total; });  
​
  x.domain(data.map(function(d) { return d.State; }));
  y.domain([0, d3.max(data, function(d) { return d.total; })]);
​
  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("Population");
​
  var state = svg.selectAll(".state")
      .data(data)
    .enter().append("g")
      .attr("class", "g")
      .attr("transform", function(d) { return "translate(" + "0" + ",0)"; });
      //.attr("transform", function(d) { return "translate(" + x(d.State) + ",0)"; })
​
   height_diff = 0;  //height discrepancy when calculating h based on data vs y(d.y0) - y(d.y1)
   state.selectAll("rect")
      .data(function(d) {
        return d.ages; 
      })
    .enter().append("rect")
      .attr("width", x.rangeBand())
      .attr("y", function(d) {
        height_diff = height_diff + y(d.y0) - y(d.y1) - (y(0) - y(d.value));
        y_corrected = y(d.y1) + height_diff;
        d.y_corrected = y_corrected //store in d for later use in restorePlot()
​
        if (d.name === "65 Years and Over") height_diff = 0; //reset for next d.mystate
          
        return y_corrected;    
        // return y(d.y1);  //orig, but not accurate  
      })
      .attr("x",function(d) { //add to stock code
          return x(d.mystate)
        })
      .attr("height", function(d) {       
        //return y(d.y0) - y(d.y1); //heights calculated based on stacked values (inaccurate)
        return y(0) - y(d.value); //calculate height directly from value in csv file
      })
      .attr("class", function(d) {        
        classLabel = d.name.replace(/\s/g, ''); //remove spaces
        return "bars class" + classLabel;
      })
      .style("fill", function(d) { return color(d.name); });
​
  state.selectAll("rect")
       .on("mouseover", function(d){
​
          var delta = d.y1 - d.y0;
          var xPos = parseFloat(d3.select(this).attr("x"));
          var yPos = parseFloat(d3.select(this).attr("y"));
          var height = parseFloat(d3.select(this).attr("height"))
​
          d3.select(this).attr("stroke","blue").attr("stroke-width",0.8);
​
          svg.append("text")
          .attr("x",xPos)
          .attr("y",yPos +height/2)
          .attr("class","tooltip")
          .text(d.name +": "+ delta); 
          
       })
       .on("mouseout",function(){
          svg.select(".tooltip").remove();
          d3.select(this).attr("stroke","pink").attr("stroke-width",0.2);
                                
        })
​
​
  var legend = svg.selectAll(".legend")
      .data(color.domain().slice().reverse())
    .enter().append("g")
      .attr("class", function (d) {
        legendClassArray.push(d.replace(/\s/g, '')); //remove spaces
        legendClassArray_orig.push(d); //remove spaces
        return "legend";
      })
      .attr("transform", function(d, i) { return "translate(0," + i * 20 + ")"; });
​
  //reverse order to match order in which bars are stacked    
  legendClassArray = legendClassArray.reverse();
  legendClassArray_orig = legendClassArray_orig.reverse();
​
  legend.append("rect")
      .attr("x", width - 18)
      .attr("width", 18)
      .attr("height", 18)
      .style("fill", color)
      .attr("id", function (d, i) {
        return "id" + d.replace(/\s/g, '');
      })
      .on("mouseover",function(){        
​
        if (active_link === "0") d3.select(this).style("cursor", "pointer");
        else {
          if (active_link.split("class").pop() === this.id.split("id").pop()) {
            d3.select(this).style("cursor", "pointer");
          } else d3.select(this).style("cursor", "auto");
        }
      })
      .on("click",function(d){        
​
        if (active_link === "0") { //nothing selected, turn on this selection
          d3.select(this)           
            .style("stroke", "black")
            .style("stroke-width", 2);
​
            active_link = this.id.split("id").pop();
            plotSingle(this);
​
            //gray out the others
            for (i = 0; i < legendClassArray.length; i++) {
              if (legendClassArray[i] != active_link) {
                d3.select("#id" + legendClassArray[i])
                  .style("opacity", 0.5);
              } else sortBy = i; //save index for sorting in change()
            }
​
            //enable sort checkbox
            d3.select("label").select("input").property("disabled", false)
            d3.select("label").style("color", "black")
            //sort the bars if checkbox is clicked            
            d3.select("input").on("change", change);  
           
        } else { //deactivate
          if (active_link === this.id.split("id").pop()) {//active square selected; turn it OFF
            d3.select(this)           
              .style("stroke", "none");
            
            //restore remaining boxes to normal opacity
            for (i = 0; i < legendClassArray.length; i++) {              
                d3.select("#id" + legendClassArray[i])
                  .style("opacity", 1);
            }
​
            
            if (d3.select("label").select("input").property("checked")) {              
              restoreXFlag = true;
            }
            
            //disable sort checkbox
            d3.select("label")
              .style("color", "#D8D8D8")
              .select("input")
              .property("disabled", true)
              .property("checked", false);   
​
​
            //sort bars back to original positions if necessary
            change();            
​
            //y translate selected category bars back to original y posn
            restorePlot(d);
​
            active_link = "0"; //reset
          }
​
        } //end active_link check
                          
                                
      });
​
  legend.append("text")
      .attr("x", width - 24)
      .attr("y", 9)
      .attr("dy", ".35em")
      .style("text-anchor", "end")
      .text(function(d) { return d; });
​
  // restore graph after a single selection
  function restorePlot(d) {
    //restore graph after a single selection
    d3.selectAll(".bars:not(.class" + class_keep + ")")
          .transition()
          .duration(1000)
          .delay(function() {
            if (restoreXFlag) return 3000;
            else return 750;
          })
          .attr("width", x.rangeBand()) //restore bar width
          .style("opacity", 1);
​
    //translate bars back up to original y-posn
    d3.selectAll(".class" + class_keep)
      .attr("x", function(d) { return x(d.mystate); })
      .transition()
      .duration(1000)
      .delay(function () {
        if (restoreXFlag) return 2000; //bars have to be restored to orig posn
        else return 0;
      })
      .attr("y", function(d) {
        //return y(d.y1); //not exactly correct since not based on raw data value
        return d.y_corrected; 
      });
​
    //reset
    restoreXFlag = false;
    
  }
​
  // plot only a single legend selection
  function plotSingle(d) {
        
    class_keep = d.id.split("id").pop();
    idx = legendClassArray.indexOf(class_keep);    
       
    //erase all but selected bars by setting opacity to 0
    d3.selectAll(".bars:not(.class" + class_keep + ")")
          .transition()
          .duration(1000)
          .attr("width", 0) // use because svg has no zindex to hide bars so can't select visible bar underneath
          .style("opacity", 0);
​
    //lower the bars to start on x-axis  
    state.selectAll("rect").forEach(function (d, i) {        
    
      //get height and y posn of base bar and selected bar
      h_keep = d3.select(d[idx]).attr("height");
      y_keep = d3.select(d[idx]).attr("y");  
​
      h_base = d3.select(d[0]).attr("height");
      y_base = d3.select(d[0]).attr("y");    
​
      h_shift = h_keep - h_base;
      y_new = y_base - h_shift;
​
      //reposition selected bars
      d3.select(d[idx])
        .transition()
        .ease("bounce")
        .duration(1000)
        .delay(750)
        .attr("y", y_new);
​
    })
   
  }
​
  //adapted change() fn in https://bl.ocks.org/mbostock/3885705
  function change() {
​
    if (this.checked) sortDescending = true;
    else sortDescending = false;
​
    colName = legendClassArray_orig[sortBy];
​
    var x0 = x.domain(data.sort(sortDescending
        ? function(a, b) { return b[colName] - a[colName]; }
        : function(a, b) { return b.total - a.total; })
        .map(function(d,i) { return d.State; }))
        .copy();
​
    state.selectAll(".class" + active_link)
         .sort(function(a, b) { 
            return x0(a.mystate) - x0(b.mystate); 
          });
​
    var transition = svg.transition().duration(750),
        delay = function(d, i) { return i * 20; };
​
    //sort bars
    transition.selectAll(".class" + active_link)
      .delay(delay)
      .attr("x", function(d) {      
        return x0(d.mystate); 
      });      
​
    //sort x-labels accordingly    
    transition.select(".x.axis")
        .call(xAxis)
        .selectAll("g")
        .delay(delay);
​
   
    transition.select(".x.axis")
        .call(xAxis)
      .selectAll("g")
        .delay(delay);    
  }
​
});
​
</script>
    