Chartjs Bar Chart Legend

chart.js, javascript

Solution

THE BELOW ANSWER IS FOR CHARTJS 1.X

So below is an example of how you can set up a legend using the labels that need to be given which each dataset, using the default legend template all you have to do is call `generateLegend()` on the chart and then place this on the page

var helpers = Chart.helpers;
var canvas = document.getElementById('bar');
var randomScalingFactor = function() {
  return Math.round(Math.random() * 100)
};
var barChartData = {
    labels: ["January", "February", "March", "April", "May", "June", "July"],
    datasets: [{
      label: "My First dataset",
      fillColor: "rgba(220,220,220,0.5)",
      strokeColor: "rgba(220,220,220,0.8)",
      highlightFill: "rgba(220,220,220,0.75)",
      highlightStroke: "rgba(220,220,220,1)",
      data: [randomScalingFactor(), randomScalingFactor(), randomScalingFactor(), randomScalingFactor(), randomScalingFactor(), randomScalingFactor(), randomScalingFactor()]
    }, {
      label: "My Second dataset",
      fillColor: "rgba(151,187,205,0.5)",
      strokeColor: "rgba(151,187,205,0.8)",
      highlightFill: "rgba(151,187,205,0.75)",
      highlightStroke: "rgba(151,187,205,1)",
      data: [randomScalingFactor(), randomScalingFactor(), randomScalingFactor(), randomScalingFactor(), randomScalingFactor(), randomScalingFactor(), randomScalingFactor()]
    }]

  }
  // 
var bar = new Chart(canvas.getContext('2d')).Bar(barChartData, {
  tooltipTemplate: "<%if (label){%><%=label%>: <%}%><%= value %>kb",
  animation: false,
});
// 
var legendHolder = document.createElement('div');
legendHolder.innerHTML = bar.generateLegend();

document.getElementById('legend').appendChild(legendHolder.firstChild);

ul {
  list-style: none;
}
ul li {
  display: block;
  padding-left: 30px;
  position: relative;
  margin-bottom: 4px;
  border-radius: 5px;
  padding: 2px 8px 2px 28px;
  font-size: 14px;
  cursor: default;
  height:20px;
  width: 140px;
  -webkit-transition: background-color 200ms ease-in-out;
  -moz-transition: background-color 200ms ease-in-out;
  -o-transition: background-color 200ms ease-in-out;
  transition: background-color 200ms ease-in-out;
}
li span {
  display: block;
  position: absolute;
  left: 0;
  top: 0;
  width: 20px;
  border-radius: 5px;
  height:20px
}

li span.bar-legend-text {
  left:25px;
  width:120px;
}
#chart-area > *{
  float:left
    }

<script src="https://raw.githack.com/chartjs/Chart.js/v1.1.1/Chart.min.js"></script>
<div id="chart-area">
  <canvas id="bar" width="250" height="250" style="width: 250px; height: 250px;"></canvas>
  <div id="legend"></div>
</div>

http://jsfiddle.net/masiht/r5g6a3cd/

Problem

I am having problems getting a legend to show up on the bar graph that I have created using chartjs. The documentation talks about a legend template, but I can't seem to find a good example of how to implement this into the graph. Below is the code I am using to generate the graph. ``` <div style="width: 100%;"> <canvas id="canvas" height="450" width="600"></canvas> <div id="legendDiv">&nbsp;</div> </div> <script> var randomScalingFactor = function(){ return Math.round(Math.random()*100)}; var barChartData = { labels : ["Item 1","Item 2","Item 3","Item 4","Item 5","Item 6","Item 7","Item 8","Item 9","Item 10","Item 11","Item 12","Item 13","Item 14","Item 15","Item 16","Item 17"] datasets : [ { fillColor : "rgba(166,166,166,0.5)", strokeColor : "rgba(166,166,166,0.8)", highlightFill: "rgba(166,166,166,0.75)", highlightStroke: "rgba(166,166,166,1)", data : [10,4,3,4,3,6,4,1,10,3,3,10,2,4,10,3,4] }, { fillColor : "rgba(196,64,54,0.5)", strokeColor : "rgba(196,64,54,0.8)", highlightFill : "rgba(196,64,54,0.75)", highlightStroke : "rgba(196,64,54,1)", data : [6,3,2,3,2,3,4,1,8,3,3,6,1,3,8,3,4] } ] } window.onload = function(){ var ctx = document.getElementById("canvas").getContext("2d"); window.myBar = new Chart(ctx).Bar(barChartData, { responsive : true }); } </script> <div> ```

Original source