Data markers in EJ2 TypeScript Chart control

23 Jun 202316 minutes to read

Data markers are used to provide information about the data points in the series. You can add a shape to adorn each data point.

Marker

Markers can be added to points by enabling the visible option of the marker property. By default, distinct markers will be enabled for each series in the chart.

index.ts
index.html
import { Chart, LineSeries, Category } from '@syncfusion/ej2-charts';
import { numData } from './datasource.ts';
Chart.Inject(LineSeries, Category);

let chart: Chart = new Chart({
    series: [
        {
            type: 'Line',
            dataSource: numData, xName: 'x', yName: 'y',
            marker: {
                visible: true
            }
        },
        {
            type: 'Line',
            dataSource: numData, xName: 'x', yName: 'y1',
            marker: {
                visible: true
            }
        }
    ],

}, '#element');
<!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>
    </div>
</body>

</html>

Shape

Markers can be assigned with different shapes such as Rectangle, Circle, Diamond, etc. using the shape property.

index.ts
index.html
import { Chart, LineSeries, Category } from '@syncfusion/ej2-charts';
import { numData } from './datasource.ts';
Chart.Inject(LineSeries, Category);

let chart: Chart = new Chart({
        series: [
            {
                type: 'Line',
                dataSource: numData, xName: 'x', yName: 'y',
                marker: {
                    visible: true,
                    shape:'Diamond',
                    height: 10, width: 10
                }
            }
        ],
}, '#element');
<!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>
    </div>
</body>

</html>

Note : To know more about the marker shape type refer the shape.

Images

Apart from the shapes, you can also add custom images to mark the data point using the imageUrl property.

index.ts
index.html
import { Chart, LineSeries, Category } from '@syncfusion/ej2-charts';
import { numData } from './datasource.ts';
Chart.Inject(LineSeries, Category);

let chart: Chart = new Chart({
         series: [
            {
                type: 'Line',
                dataSource: numData, xName: 'x', yName: 'y',
                //Marker shape as image
                marker: {
                    visible: true,
                    width: 10, height: 10,
                    shape: 'Image',
                    imageUrl:'sun_annotation.png'
                }
            }
        ],

}, '#element');
<!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>
    </div>
</body>

</html>

Customization

Marker’s color and border can be customized using fill and border properties.

index.ts
index.html
import { Chart, LineSeries, Category } from '@syncfusion/ej2-charts';
import { numData } from './datasource.ts';
Chart.Inject(LineSeries, Category);

let chart: Chart = new Chart({
        series: [
            {
                type: 'Line',
                dataSource: numData, xName: 'x', yName: 'y',
                marker: {
                    visible: true,
                    fill: 'Red', height: 10, width: 10,
                    border:{width: 2, color: 'blue'},
                }
            }
        ],

}, '#element');
<!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>
    </div>
</body>

</html>

Customizing specific point

You can also customize the specific marker and label using pointRender event. The pointRender event allows you to change the shape, color and border for a point.

index.ts
index.html
import { Chart, LineSeries, IPointRenderEventArgs } from '@syncfusion/ej2-charts';
import { numData } from './datasource.ts';
Chart.Inject(LineSeries);

let chart: Chart = new Chart({
    series: [
        {
            type: 'Line',
            dataSource: numData, xName: 'x', yName: 'y',
            marker: {
                visible: true,
                height: 10, width: 10,
            }
        }
    ],
    // pointRender event for chart
    pointRender: (args: IPointRenderEventArgs) => {
        if (args.point.index === 3) {
            args.fill = 'red'
        }
    },
}, '#element');
<!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>
    </div>
</body>

</html>

Fill marker with series color

Marker can be filled with the series color by setting the isFilled property to true.

index.ts
index.html
import { Chart, LineSeries, Category } from '@syncfusion/ej2-charts';
import { numData } from './datasource.ts';
Chart.Inject(LineSeries, Category);

let chart: Chart = new Chart({
        series: [
            {
                type: 'Line',
                dataSource: numData, xName: 'x', yName: 'y',
                marker: {
                    visible: true, isFilled:true,
                    height: 10, width: 10,
                }
            }
        ],

}, '#element');
<!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>
    </div>
</body>

</html>