Dynamically Add Chart Event Listener Using AngularJS

FusionCharts Suite XT includes advanced features that let you add more context to your chart and make data visualization simpler. These features include chart updates and option to add/remove events at runtime.

Events are signals that let you execute specific actions - such as manipulate the DOM, send data to the server, etc., using JavaScript, in response to any interaction/update of a chart. For example, you can use events to trigger action(s) when a chart renders successfully, when data completes loading, when a data plot is clicked, when the mouse pointer is hovered over a data plot, and so on.

This article focuses on how you can dynamically add/remove event listener to the data plots in the chart using angularjs-fusioncharts component.

A chart is shown below:

FusionCharts will load here..
{
    "chart": {
        "caption": "Countries With Most Oil Reserves [2017-18]",
        "subCaption": "In MMbbl = One Million barrels",
        "xAxisName": "Country",
        "yAxisName": "Reserves (MMbbl)",
        "numberSuffix": "K",
        "theme": "fusion"
    },
    "data": [
        {
            "label": "Venezuela",
            "value": "290"
        },
        {
            "label": "Saudi",
            "value": "260"
        },
        {
            "label": "Canada",
            "value": "180"
        },
        {
            "label": "Iran",
            "value": "140"
        },
        {
            "label": "Russia",
            "value": "115"
        },
        {
            "label": "UAE",
            "value": "100"
        },
        {
            "label": "US",
            "value": "30"
        },
        {
            "label": "China",
            "value": "30"
        }
    ]
}

The code to render the above chart is given below:

//  Require AngularJS 
var angular = require('angular');

// Require FusionCharts 
var FusionCharts = require('fusioncharts');

// Require angularjs-fusioncharts 
require('angularjs-fusioncharts');

// Require Chart modules 
var Charts = require('fusioncharts/fusioncharts.charts');

// Require Fusion theme
var FusionTheme = require('fusioncharts/themes/fusioncharts.theme.fusion');

// Initialize Charts with FusionCharts instance
Charts(FusionCharts);

// Initialize FusionTheme with FusionCharts instance
FusionTheme(FusionCharts);

var myApp = angular.module("myApp", ["ng-fusioncharts"]);
myApp.controller("MyController", ["$scope", function($scope) {
    var disableStyle = {
        "border-color": "#d3d3d3",
        "color": "#d3d3d3",
        "background": "none",
        "cursor": "default"
    },
    activeStyle = {
        "border-color": "#6957da",
        "cursor": "pointer"
    };
    $scope.message = "Click the below buttons to add an event dynamically to the chart";
    $scope.myDataSource = {
        "chart": {
            "caption": "Countries With Most Oil Reserves [2017-18]",
            "subCaption": "In MMbbl = One Million barrels",
            "xAxisName": "Country",
            "yAxisName": "Reserves (MMbbl)",
            "numberSuffix": "K",
            "theme": "fusion"
        },
        "data": [{
            "label": "Venezuela",
            "value": "290"
        }, {
            "label": "Saudi",
            "value": "260"
        }, {
            "label": "Canada",
            "value": "180"
        }, {
            "label": "Iran",
            "value": "140"
        }, {
            "label": "Russia",
            "value": "115"
        }, {
            "label": "UAE",
            "value": "100"
        }, {
            "label": "US",
            "value": "30"
        }, {
            "label": "China",
            "value": "30"
        }]
    };
    $scope.trackButton = activeStyle;
    $scope.resetButton = disableStyle;

    // handler for dataplotclick event
    $scope.clickHandler = function(e) {
        $scope.$apply(function() {
            $scope.message = "You have clicked on plot <b>" + e.data.categoryLabel + "</b> whose value is <b>" + e.data.displayValue + "</b>";
        });
    };
    $scope.track = function() {
        FusionCharts.addEventListener("dataplotclick", $scope.clickHandler);
        $scope.message = "Click on the plot to see the value along with the label";
        $scope.trackButton = disableStyle;
        $scope.resetButton = activeStyle;
    };
    $scope.reset = function() {
        FusionCharts.removeEventListener("dataplotclick", $scope.clickHandler);
        $scope.message = "Click the below buttons to add an event dynamically to the chart";
        $scope.trackButton = activeStyle;
        $scope.resetButton = disableStyle;
    }
    // unlisten to dataplotclick event when the view gets destroyed.
    $scope.$on("$destroy", function() {
        FusionCharts.removeEventListener("dataplotclick", $scope.clickHandler);
    });
}]);

Now, use the fusioncharts directive in a template. The HTML template is given below:

<div ng-app="myApp">
    <div ng-controller="MyController"> 
        <div id="chart-container">
            <fusioncharts
                type="column2d"
                width="100%"
                height="500"
                dataFormat="json"
                datasource="{{myDataSource}}">
            </fusioncharts>
          </div>
          <p ng-bind-html="message" style="padding: 10px; background: #f5f2f0"></p>
          <div style="display: flex; justify-content: center">
            <a ng-click="track()" ng-style="trackButton">LISTEN TO DATAPLOTCLICK EVENT</a>
            <a ng-click="reset()" ng-style="resetButton">REMOVE DATAPLOTCLICK EVENT</a>
          </div>
      </div>
</div>

Render the above chart by following the steps mentioned below:

  1. Include the necessary libraries (such as fusioncharts and angularjs-fusioncharts) and components using require.

  2. Add the chart and the theme as dependencies to the core.

  3. Store the chart configurations in a variable (myApp).

  4. Set the message and its styling, which get displayed while rendering the chart.

  5. Store the data source in a variable (dataSource).

  6. Set the scope for the buttons.

  7. Add the addEventListener to:

    • Track plot clicks.
    • Track the clicks on the data plot.
    • Set the default message when data plot tracking is enabled.
    • Set the event listener for dataPlotClick event when the message is updated with the values of the data plot.
    • Set the handler for Reset button. The Reset button resets the chart to default message and removes the event listener.
  8. Add the <div> with an fc-chart directive in your HTML, assuming that it is inside a controller named MyController. In the div:

    • Set the chart type as column2d. Find the complete list of chart types with their respective aliases here.
    • Set the width and the height of the chart in pixels.
    • Embed the JSON data from dataSource.
  9. Create a <div> to add buttons using <a>.