Angular-Charts - Pie Chart,show labels inside each slice of data

Question

I am learning stage of angular-chart-js. I am trying to use angular-chart.js to plot a pie chart. But I am unable to find a way for showing labels (not tooltips) on the pie chart, which describe each slice of data.

Here is how I did it:

angular.module('App').controller('Controller', ['$scope', '$http', '$location', '$window', '$routeParams',
    function($scope, $http, $location, $window) {
        var diskDataJson = {
            "data": [80, 12],
            "labels": [Used space, Free Space],
            "colours": ['#9AB6F0', '#C2D3F6']
        };
    
        $scope.pieDiskData = json;
    }
]);

<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.23/angular.min.js"></script>
<table border="0" width="100%">
  <tr>
    <td style="border-left: 1px solid #0099CC" width="25%">
      <center><span><label ng-bind-html="'load.static.dashboard.system.DUSAGE' | translate"/></span>
      </center>
      <canvas id="pie33" class="chart chart-pie chart-xs ng-isolate-scope" height="120" width="240" data="pieDiskData.data" labels="pieDiskData.labels" colours="pieDiskData.colours" legend="true"></canvas>
    </td>
  </tr>
</table>

Answer 1

Adapted from https://stackoverflow.com/a/25913101/360067 for angular-chart

Add the following options to your scope

$scope.options = {
    tooltipEvents: [],
    showTooltips: true,
    tooltipCaretSize: 0,
    onAnimationComplete: function () {
        this.showTooltip(this.segments, true);
    },
};

And use that in your directive

<canvas id="pie33" options="options"...

---

Fiddle (with relevant sections from your code) - http://jsfiddle.net/zuhp8k5f/154/

---

Answer 2

You can also use a custom plugin to achieve the same behaviour.

1.Make sure you have showAllTooltips set to true

  options: any = {showAllTooltips: true,legend: {position: 'left'}};

2.Register your custom plugin on ngOnInit

    Chart.pluginService.register({
  beforeRender: function (chart) {
    if (chart.config.options.showAllTooltips) {
      // create an array of tooltips
      // we can't use the chart tooltip because there is only one tooltip per chart
      chart.pluginTooltips = [];
      chart.config.data.datasets.forEach(function (dataset, i) {
        chart.getDatasetMeta(i).data.forEach(function (sector, j) {
          chart.pluginTooltips.push(new Chart.Tooltip({
            _chart: chart.chart,
            _chartInstance: chart,
            _data: chart.data,
            _options: chart.options.tooltips,
            _active: [sector]
          }, chart));
        });
      });

      // turn off normal tooltips
      chart.options.tooltips.enabled = false;
    }
  },
  afterDraw: function (chart, easing) {
    if (chart.config.options.showAllTooltips) {
      // we don't want the permanent tooltips to animate, so don't do anything till the animation runs atleast once
      if (!chart.allTooltipsOnce) {
        if (easing !== 1) {
          return;
        }
        chart.allTooltipsOnce = true;
      }

      // turn on tooltips
      chart.options.tooltips.enabled = true;
      Chart.helpers.each(chart.pluginTooltips, function (tooltip) {
        tooltip.initialize();
        tooltip.update();
        // we don't actually need this since we are not animating tooltips
        tooltip.pivot();
        tooltip.transition(easing).draw();
      });
      chart.options.tooltips.enabled = false;
    }
  }
});