Dynamic data update in EJ2 TypeScript Chart control

13 Jun 202423 minutes to read

Adding a new data point

The addPoint method is used to dynamically add a new data point to the chart series. This method is particularly useful when you want to update the chart with a new data point without having to refresh the entire chart. This method takes two parameters:

  • The first parameter is the new data point to add to your existing data source.
  • The optional second parameter specifies the animation duration for adding the new data point.
import { Chart, SplineSeries, Category, DataLabel, Legend } from '@syncfusion/ej2-charts';
Chart.Inject(SplineSeries, Category, DataLabel, Legend);

let addData: Object[] = [
    { x: "Germany", y: 72 },
    { x: "Russia", y: 103.1 },
    { x: "Brazil", y: 139.1 },
    { x: "India", y: 462.1 },
    { x: "China", y: 721.4 },
    { x: "USA", y: 286.9 },
    { x: "Great Britain", y: 115.1 },
    { x: "Nigeria", y: 97.2 }
];

let chart: Chart = new Chart({
    primaryXAxis: {
        valueType: 'Category', enableTrim: false, majorTickLines: { width: 0 }, majorGridLines: { width: 0 }
    },
    chartArea: { border: { width: 1 } },
    primaryYAxis:
    {
        minimum: 0, maximum: 800, labelFormat: '{value}M', edgeLabelPlacement: 'Shift'
    },
    series: [
        {
            dataSource: addData, xName: 'x', yName: 'y', type: 'Spline', width: 2, name: 'Users',
            marker: { visible: true, dataLabel: { visible: true, position: 'Top', font: { fontWeight: '600' } } }
        }
    ],
    title: 'Internet Users - 2016',
    legendSettings: {
        visible: false
    }
}, '#element');

document.getElementById('add').onclick = function () {
    chart.series[0].addPoint({ x: 'Japan', y: 118.2 });
}
<!DOCTYPE html>
<html lang="en">

<head>
    <title>EJ2 Animation</title>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <meta name="description" content="Typescript UI Controls" />
    <meta name="author" content="Syncfusion" />
    <link href="index.css" rel="stylesheet" />
    <script src="https://cdnjs.cloudflare.com/ajax/libs/systemjs/0.19.38/system.js"></script>
    <script src="systemjs.config.js"></script>
<script src="https://cdn.syncfusion.com/ej2/syncfusion-helper.js" type ="text/javascript"></script>
</head>

<body>
    <div id='loader'>Loading....</div>
    <div id='container'>
        <div id='element'></div>
        <button id='add'>Add Point</button>
    </div>
</body>

</html>

Removing an existing data point

The removePoint method is used to dynamically remove a data point from the chart series. This method is particularly useful when you want to update the chart by removing an existing data point without having to refresh the entire chart. This method takes two parameters:

  • The first parameter is the index of the data point that needs to be removed from the existing data source.
  • The optional second parameter specifies the animation duration for removing the data point.
import { Chart, SplineSeries, Category, DataLabel, Legend } from '@syncfusion/ej2-charts';
Chart.Inject(SplineSeries, Category, DataLabel, Legend);

let removeData: Object[] = [
    { x: "Germany", y: 72 },
    { x: "Russia", y: 103.1 },
    { x: "Brazil", y: 139.1 },
    { x: "India", y: 462.1 },
    { x: "China", y: 721.4 },
    { x: "USA", y: 286.9 },
    { x: "Great Britain", y: 115.1 },
    { x: "Nigeria", y: 97.2 }
];

let chart: Chart = new Chart({
    primaryXAxis: {
        valueType: 'Category', enableTrim: false, majorTickLines: { width: 0 }, majorGridLines: { width: 0 }
    },
    chartArea: { border: { width: 1 } },
    primaryYAxis:
    {
        minimum: 0, maximum: 800, labelFormat: '{value}M', edgeLabelPlacement: 'Shift'
    },
    series: [
        {
            dataSource: removeData, xName: 'x', yName: 'y', type: 'Spline', width: 2, name: 'Users',
            marker: { visible: true, dataLabel: { visible: true, position: 'Top', font: { fontWeight: '600' } } }
        }
    ],
    title: 'Internet Users - 2016',
    legendSettings: {
        visible: false
    }
}, '#element');

document.getElementById('remove').onclick = function () {
    chart.series[0].removePoint(0);
}
<!DOCTYPE html>
<html lang="en">

<head>
    <title>EJ2 Animation</title>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <meta name="description" content="Typescript UI Controls" />
    <meta name="author" content="Syncfusion" />
    <link href="index.css" rel="stylesheet" />
    <script src="https://cdnjs.cloudflare.com/ajax/libs/systemjs/0.19.38/system.js"></script>
    <script src="systemjs.config.js"></script>
<script src="https://cdn.syncfusion.com/ej2/syncfusion-helper.js" type ="text/javascript"></script>
</head>

<body>
    <div id='loader'>Loading....</div>
    <div id='container'>
        <div id='element'></div>
        <button id='remove'>Remove Point</button>
    </div>
</body>

</html>

Replacing entire data points

To replace the existing data source in the chart with a new data source, you can simply use the setData method. This method allows you to replace the existing data points in the chart series with a new set of data points, enabling you to easily update the chart with new information. This method takes two parameters:

  • The first parameter is the new set of data points to be updated.
  • The optional second parameter specifies the animation duration for updating the new data source.
import { Chart, ColumnSeries, Category, IAxisRangeCalculatedEventArgs } from '@syncfusion/ej2-charts';
Chart.Inject(ColumnSeries, Category);

let updatedData: Object[] = [
    { x: 'Jewellery', y: 75 },
    { x: 'Shoes', y: 45 },
    { x: 'Footwear', y: 73 },
    { x: 'Pet Services', y: 53 },
    { x: 'Business Clothing', y: 85 },
    { x: 'Office Supplies', y: 68 },
    { x: 'Food', y: 45 }
];

let chart: Chart = new Chart({
    primaryXAxis: {
        valueType: 'Category', majorGridLines: { width: 0 }, labelStyle: { size: '12px' }, labelIntersectAction: 'Rotate90'
    },
    chartArea: { border: { width: 0 } },
    primaryYAxis:
    {
        title: 'Sales (in percentage)', labelFormat: '{value}%', lineStyle: { width: 0 }, majorTickLines: { width: 0 }, interval: 5, minimum: 0, maximum: 100
    },
    series: [
        {
            dataSource: updatedData, xName: 'x', yName: 'y', type: 'Column',
            cornerRadius: { topLeft: 15, topRight: 15 }, columnWidth: 0.5
        }
    ],
    title: 'Sales by product',
    axisRangeCalculated: (args: IAxisRangeCalculatedEventArgs) => {
        if (args.axis.name === 'primaryYAxis') {
            args.maximum = args.maximum as number > 100 ? 100 : args.maximum;
            if (args.maximum > 80) {
                args.interval = 20;
            }
            else if (args.maximum > 40) {
                args.interval = 10;
            }
        }
    }
}, '#element');

function getRandomInt(min: number, max: number) {
    return Math.floor(Math.random() * (max - min + 1)) + min;
}
document.getElementById('update').onclick = () => {
    const newData = updatedData.map((item: { x: string, y: number }) => {
        const value: number = getRandomInt(10, 90);
        return { x: item.x, y: value };
    });
    if (chart.series.length > 0) {
        chart.series[0].setData(newData, 500);
    }
}
<!DOCTYPE html>
<html lang="en">

<head>
    <title>EJ2 Animation</title>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <meta name="description" content="Typescript UI Controls" />
    <meta name="author" content="Syncfusion" />
    <link href="index.css" rel="stylesheet" />
    <script src="https://cdnjs.cloudflare.com/ajax/libs/systemjs/0.19.38/system.js"></script>
    <script src="systemjs.config.js"></script>
<script src="https://cdn.syncfusion.com/ej2/syncfusion-helper.js" type ="text/javascript"></script>
</head>

<body>
    <div id='loader'>Loading....</div>
    <div id='container'>
        <div id='element'></div>
        <button id='update'>Update Data</button>
    </div>
</body>

</html>

Click to add or remove a data point

You can use mouse or touch events to dynamically add or remove data points from an existing data source by clicking on the appropriate position within the chart area. To add a new data point to the existing data source, click anywhere in the chart area, retrieve the x-axis and y-axis information of the clicked location from the chartMouseClick event arguments. Then, utilize the addPoint method to add a new data point to the existing data source.

To remove a data point from the existing data source, simply click on the desired data point. To achieve this, first, verify whether the clicked data point obtained from chartMouseClick already exists in the data source. If it does, remove it by utilizing the removePoint method based on its index.

import { Chart, LineSeries, DataLabel, Tooltip, IMouseEventArgs, IAxisRangeCalculatedEventArgs, Series } from '@syncfusion/ej2-charts';
Chart.Inject(LineSeries, DataLabel, Tooltip);

let chartData: Object[] = [
    { x: 20, y: 20 }, { x: 80, y: 80 }
];

let chart: Chart = new Chart({
    primaryXAxis: {
        edgeLabelPlacement: 'Shift', rangePadding: 'Additional', majorGridLines: { width: 0 }
    },
    chartArea: { border: { width: 0 } },
    primaryYAxis:
    {
        title: 'Value', interval: 20, lineStyle: { width: 0 }, majorTickLines: { width: 0 }
    },
    series: [
        {
            dataSource: chartData, xName: 'x', yName: 'y', type: 'Line', width: 3,
            marker: { visible: true, isFilled: true, border: { width: 2, color: 'White' }, width: 13, height: 13 }
        }
    ],
    title: 'User supplied data',
    tooltip: { enable: true },
    chartMouseClick: (args: IMouseEventArgs) => {
        let isRemoved: boolean = false;
        if (args.axisData) {
            for (let i: number = 0; i < (chart.series[0] as Series).points.length; i++) {
                let markerWidth: number = (chart.series[0] as Series).marker.width / 2;
                let roundedX: number = Math.round(args.axisData['primaryXAxis']) + markerWidth;
                let roundedY: number = Math.round(args.axisData['primaryYAxis']) + markerWidth;
                let pointX: number = Math.round((chart.series[0] as Series).points[i].x as number) + markerWidth;
                let pointY: number = Math.round((chart.series[0] as Series).points[i].y as number) + markerWidth;
                if ((roundedX === pointX || roundedX + 1 === pointX || roundedX - 1 === pointX) &&
                    (roundedY === pointY || roundedY + 1 === pointY || roundedY - 1 === pointY)) {
                    if ((chart.series[0] as Series).points.length > 1) {
                        const points = (chart.series[0] as Series).points;
                        const duration: number = i === 0 || i === points[points.length - 1].index ? 500 : 0;
                        chart.series[0].removePoint(i, duration);
                    }
                    isRemoved = true;
                }
            }
            if (!isRemoved) {
                chart.series[0].addPoint({x: Math.round(args.axisData['primaryXAxis']), y: Math.round(args.axisData['primaryYAxis'])});
            }
        }
    },
    axisRangeCalculated: (args: IAxisRangeCalculatedEventArgs)  => {
        if (args.axis.name === 'primaryXAxis') {
            if (args.interval < 10) {
                args.maximum = args.maximum + 10;
                args.minimum = args.minimum - 10;
                args.interval = 10;
            }
        }
        if (args.axis.name === 'primaryYAxis') {
            if (args.maximum <= 60) {
                args.interval = 10;
            }
        }
    }
}, '#addPoint');
<!DOCTYPE html>
<html lang="en">

<head>
    <title>EJ2 Animation</title>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <meta name="description" content="Typescript UI Controls" />
    <meta name="author" content="Syncfusion" />
    <link href="index.css" rel="stylesheet" />
    <script src="https://cdnjs.cloudflare.com/ajax/libs/systemjs/0.19.38/system.js"></script>
    <script src="systemjs.config.js"></script>
<script src="https://cdn.syncfusion.com/ej2/syncfusion-helper.js" type ="text/javascript"></script>
</head>

<body>
    <div id='loader'>Loading....</div>
    <div id='container'>
        <div id='addPoint'></div>
    </div>
</body>

</html>