Bind Event Listener

Events are signals that let you execute specific actions—such as manipulating the DOM, sending data to the server, and so on—using JavaScript, in response to any interactions/updates for a chart. Events can be used 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.

Events can be used for applications like monitoring the state of a system or a business. For example, you can listen to an event to observe the temperature of a deep freezer and display an alert message if the temperature falls below the minimum value.

Take a look at the Column 2D chart shown below:

FusionCharts will load here..

Roll the mouse pointer over any one data plot and see how the text (the data label and the value) rendered below the chart changes.

For example, if you roll the mouse pointer over the Canada data plot, the following text is displayed below the chart:

You are currently hovering over Canada whose value is 180

Setup ember-cli-build.js

In this step we will include all the necessary files and add the dependency to create the Column 2D chart. The code is given below:

/* eslint-env node */
'use strict';

const EmberAddon = require('ember-cli/lib/broccoli/ember-addon');

module.exports = function (defaults) {
    let app = new EmberAddon(defaults, {
        // Add options here
    });

    // Import FusionCharts library
    app.import('bower_components/fusioncharts/fusioncharts.js');
    app.import('bower_components/fusioncharts/fusioncharts.charts.js');        
    app.import('bower_components/fusioncharts/themes/fusioncharts.theme.fusion.js');    

    return app.toTree();
};

In the above code, include the necessary libraries and components using import. For example, ember-fusioncharts, fusioncharts, etc.

If you need to use different assets in different environments, specify an object as the first parameter. That object's keys should be the environment name and the values should be the asset to use in that environment.

Add chart data to chart-viewer.js

Add the following code to chart-viewer.js:

import Component from '@ember/component';

export default Component.extend({    
    width: 700,
    height: 400,
    type: 'column2d',
    dataFormat: 'json',
    dataSource: {
        "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"
        }]
    },
    events: null,
    message: 'Hover on the plot to see the value along with the label',

    init() {
        this._super(...arguments);
        const self = this;
        this.set('events', {
            dataplotRollOver: function (eventObj, dataObj) {
                self.set('message', 'You are currently hovering over ' + dataObj.categoryLabel + ' whose value is ' + dataObj.displayValue);
            },
            dataPlotRollOut: function(eventObj, dataObj) {                
                self.set('message', 'Hover on the plot to see the value along with the label');
            }
        });
    }    
});

In the above code:

  1. Create a chart component to render the chart.

  2. Store the chart configuration in a JSON object. In the JSON object:

    • Set the chart type as column2d. Find the complete list of chart types with their respective alias here.
    • Set the width and height of the chart in pixels.
    • Set the dataFormat as JSON.
    • Embed the json data as the value of dataSource.
  3. Set the message which gets displayed with the rendering of the chart.

  4. Call the init() funtion where:

    • Callback handler for dataplotRollOver event has been used which is triggered when the mouse pointer is rolled over a data plot.
    • Callback handler for dataplotRollOut event has been used which is triggered when the mouse pointer is rolled out of the data plot.

Add data to chart-viewer.hbs

Add the following code to chart-viewer.hbs:

{{fusioncharts-xt
    width=width
    height=height
    type=type
    dataFormat=dataFormat
    dataSource=dataSource
    events=events}}

<p>{{ message }}</p>

In the above code, add the fusioncharts to render the chart.