Unable to get series vale for chart-click in angular stacked bar graph - angularjs

Question

<canvas class="chart chart-bar" chart-data="data" chart-labels="labels"
chart-options="options" chart-series="series" chart-click="onclick"></canvas>
'use strict';
var app = angular.module('examples', ['chart.js', 'ui.bootstrap']);
app.controller('StackedBarCtrl', ['$scope', function ($scope) {
$scope.labels = ['Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday', 'Sunday'];
$scope.type = 'StackedBar';
$scope.series = ['2015', '2016'];
$scope.options = {
scales: {
xAxes: [{
stacked: true,
}],
yAxes: [{
stacked: true
}]
}
};
$scope.onclick = function(points,evt)
{
console.log("evt "+points[0]["_modal"]["datasetLabel"]);
}
$scope.data = [
[65, 59, 90, 81, 56, 55, 40],
[28, 48, 40, 19, 96, 27, 100]
];
}]);
If i click on bar 28 i am not getting the value 2016, because points array in onclick function return 2 objects on for each stack and i am unable to figure out how to get value 2016 as there is no flag to indicate which bar was clicked upon

Answer 1

The second argument passed to your onclick callback contains array of active elements and each item in it contains _datasetIndex and _index
array[1]
[Element]
_datasetIndex:0
_index: 0
Using these values you can obtain the value you need
$scope.onclick = function(event, elems)
{
var datasetIndex = elems[0]._datasetIndex;
console.log("evt " + $scope.series[datasetIndex]);
}
Please, refer to chartjs docs and this issue related to your problem
UPDATE
Looks like it is a little tricky with stacked bar charts. The solution is to find the closest clicked bar using Chart.helpers
$scope.$on('chart-create', function(event, instance){
// used to obtain chart instance
$scope.chart = instance.chart;
});
$scope.onclick = function(elements,e)
{
// helper function that translates an event to a position in canvas coordinates
var pos = Chart.helpers.getRelativePosition(e, $scope.chart);
// inRange is the function on the chart element that is used for hit testing
var intersect = elements.find(function(element) {
return element.inRange(pos.x, pos.y);
});
if(intersect){
alert('You clicked ' + $scope.labels[intersect._index] + ' ' + $scope.series[intersect._datasetIndex]);
}
}
Here is the working plunkr