Data labels in EJ2 TypeScript Sparkline control

18 Apr 20238 minutes to read

Data labels are used to display values of data points to improve the readability.

Enable data label

To enable data label for sparkline series, provide visible of the dataLabelSettings as following possible values:

All - Enables data label of all points.
Start - Enables data label of the start point.
End - Enables data label of the end point.
High - Enables data label of the high point.
Low - Enables data label of the low point.
Negative - Enables data labels of the negative points.

The following example shows enabling sparkline data label for all points.

index.ts
index.html
import { Sparkline } from '@syncfusion/ej2-charts';

let sparkline: Sparkline = new Sparkline({
    height: '200px',
    width: '350px',
    axisSettings: {
        minX: -1, maxX: 7, maxY: 7, minY: -1
    },
    fill: 'blue',
    dataSource:   [0, 6, 4, 1, 3, 2, 5],
    // To enable data label for all points
    dataLabelSettings: {
        visible: ['All']
    },
});
sparkline.appendTo("#element");
<!DOCTYPE html>
<html lang="en">

<head>
    <title>Essential JS 2 for Sparkline </title>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <meta name="description" content="Essential JS 2 for Sparkline UI Control" />
    <meta name="author" content="Syncfusion" />
    <link href="index.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-charts/styles/material.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' style="margin-top: 15%;">
            <div id="element" align="center" ></div>
    </div>
</body>

</html>

Customize data label

Data labels can be customized using the fill, border, opacity, and textStyle. The following code example shows customizing data label border, text color, and fill color.

index.ts
index.html
import { Sparkline } from '@syncfusion/ej2-charts';

 let sparkline: Sparkline = new Sparkline({
    height: '200px',
    width: '350px',
    axisSettings: {
        minX: -1, maxX: 7, maxY: 8, minY: -1
    },
    fill: 'blue',
    dataSource:   [0, 6, 4, 1, 3, 2, 5],
    // To customize data label fill, border, and text color
    dataLabelSettings: {
        visible: ['All'],
        border: { color: 'blue', width: 1},
        fill: 'blue', opacity: 0.4,
        textStyle: {
            color: 'white'
        }
    },
});
sparkline.appendTo("#element");
<!DOCTYPE html>
<html lang="en">

<head>
    <title>Essential JS 2 for Sparkline </title>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <meta name="description" content="Essential JS 2 for Sparkline UI Control" />
    <meta name="author" content="Syncfusion" />
    <link href="index.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-charts/styles/material.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' style="margin-top: 15%;">
            <div id="element" align="center" ></div>
    </div>
</body>

</html>

Format data label text

The text of data labels can be formatted using the format API in the sparkline dataLabelSettings. By default, data label shows the y-value of point. The following code example shows how to display x and y-values for points.

index.ts
index.html
import { Sparkline } from '@syncfusion/ej2-charts';

 let sparkline: Sparkline = new Sparkline({
    height: '200px',
    width: '500px',
    axisSettings: {
        minX: -1, maxX: 7, maxY: 8, minY: -1
    },
    fill: 'blue',
    valueType: 'Category',
    xName: 'x', yName: 'y',
    dataSource:   [{x: 'Mon', y: 3 },{x: 'Tue', y: 5 },{x: 'Wed', y: 2 },{x: 'Thu', y: 4 },{x: 'Fri', y: 6 },],
    // To enable data label for all points
    dataLabelSettings: {
        format: '${x} : ${y}',
        visible: ['All'],
        border: { color: 'blue', width: 1},
        fill: 'blue', opacity: 0.4,
        textStyle: {
            color: 'white'
        }
    },
});
sparkline.appendTo("#element");
<!DOCTYPE html>
<html lang="en">

<head>
    <title>Essential JS 2 for Sparkline </title>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <meta name="description" content="Essential JS 2 for Sparkline UI Control" />
    <meta name="author" content="Syncfusion" />
    <link href="index.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-charts/styles/material.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' style="margin-top: 15%;">
            <div id="element" align="center" ></div>
    </div>
</body>

</html>