Tooltip in EJ2 TypeScript Chart control

19 Dec 202423 minutes to read

Chart will display details about the points through tooltip, when the mouse is moved over the point.

Default tooltip

By default, tooltip is not visible. You can enable the tooltip by setting enable property to true and by injecting Tooltip module using Chart.Inject(Tooltip).

import { Chart, StepLineSeries, DateTime, Tooltip } from '@syncfusion/ej2-charts';
import { chartData } from './datasource.ts';
Chart.Inject(StepLineSeries, DateTime, Tooltip);

let chart: Chart = new Chart({
        primaryXAxis: {
            valueType: 'DateTime'
        },
        series: [
            {
                type: 'StepLine',
                dataSource: chartData, xName: 'x', yName: 'y',
                width: 2, name: 'China',
                marker: {
                    visible: true, width: 10, height: 10
                },
            }],
        title: 'Unemployment Rates 1975-2010',
        //Default tooltip for chart
        tooltip: {enable: 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>
     <script id="Unemployment" type="text/x-template">
      <div id='templateWrap'>
     <table style="width:100%;  border: 1px solid black;">
     <tr><th colspan="2" bgcolor="#00FFFF">Unemployment</th></tr>
     <tr><td bgcolor="#00FFFF">${x}:</td><td bgcolor="#00FFFF">${y}</td></tr>
    </table>
    </div>
  </script>
</body>

</html>

Fixed tooltip

By default, tooltip track the mouse movement, but you can set a fixed position for the tooltip by using the location property.

import { Chart, StepLineSeries, DateTime, Tooltip } from '@syncfusion/ej2-charts';
import { chartData } from './datasource.ts';
Chart.Inject(StepLineSeries, DateTime, Tooltip);

let chart: Chart = new Chart({
    primaryXAxis: {
        valueType: 'DateTime'
    },
    primaryYAxis: {
        minimum: 0,
        maximum: 20,
        interval: 4
    },
    series: [
        {
            type: 'StepLine',
            dataSource: chartData, xName: 'x', yName: 'y',
            width: 2, name: 'China',
            marker: {
                visible: true, width: 10, height: 10
            },
        }],
    title: 'Unemployment Rates 1975-2010',
    //Default tooltip for chart
    tooltip: { enable: true, location: { x: 120, y: 20 } }
}, '#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>

Format the tooltip

By default, tooltip shows information of x and y value in points. In addition to that, you can show more information in tooltip. For example the format ${series.name} ${point.x} shows series name and point x value.

import { Chart, SplineSeries, DateTime, Tooltip } from '@syncfusion/ej2-charts';
import { chartData } from './datasource.ts';
Chart.Inject(SplineSeries, DateTime, Tooltip);

let chart: Chart = new Chart({
        primaryXAxis: {
            valueType: 'DateTime',
        },
        series: [
            {
                type: 'Spline',
                dataSource: chartData, xName: 'x', yName: 'y',
                width: 2, name: 'China',
                marker: {
                    visible: true, width: 10, height: 10
                },
            }
        ],
        title: 'Unemployment Rates 1975-2010',
        tooltip: {
            enable: true,
            //tooltip format for chart
             header: 'Unemployment',
             format: '<b>${point.x} : ${point.y}</b>'
        }
}, '#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>
     <script id="Unemployment" type="text/x-template">
      <div id='templateWrap'>
     <table style="width:100%;  border: 1px solid black;">
     <tr><th colspan="2" bgcolor="#00FFFF">Unemployment</th></tr>
     <tr><td bgcolor="#00FFFF">${x}:</td><td bgcolor="#00FFFF">${y}</td></tr>
    </table>
    </div>
  </script>
</body>

</html>

Tooltip template

Any HTML elements can be displayed in the tooltip by using the template property of the tooltip. You can use the ${x} and ${y} as place holders in the HTML element to display the x and y values of the corresponding data point.

import { Chart, StepLineSeries, Legend, Tooltip } from '@syncfusion/ej2-charts';
import { data } from './datasource.ts';
Chart.Inject(StepLineSeries, Legend, Tooltip);

let chart: Chart = new Chart({
        series: [
            {
                type: 'StepLine',
                dataSource: data, xName: 'x', yName: 'y',
                width: 2, name: 'China',
                marker: {
                    visible: true, width: 10, height: 10
                },
            }
        ],
        title: 'Unemployment Rates 1975-2010',
        tooltip: {
            enable: true,
            //tooltip template for chart
            template: '#Unemployment'
        }
}, '#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>
     <script id="Unemployment" type="text/x-template">
      <div id='templateWrap'>
     <table style="width:100%;  border: 1px solid black;">
     <tr><th colspan="2" bgcolor="#00FFFF">Unemployment</th></tr>
     <tr><td bgcolor="#00FFFF">${x}:</td><td bgcolor="#00FFFF">${y}</td></tr>
    </table>
    </div>
  </script>
</body>

</html>

Enable highlight

By setting the enableHighlight property to true, you can highlight all points in the hovered series while dimming points in other series, enhancing focus and clarity.

import { Chart, StepLineSeries, DateTime, Tooltip, Legend } from '@syncfusion/ej2-charts';
import { chartData } from './datasource.ts';
Chart.Inject(StepLineSeries, DateTime, Tooltip, Legend);

let chart: Chart = new Chart({
    primaryXAxis: {
        title: 'Years',
        lineStyle: { width: 0 },
        labelFormat: 'y',
        intervalType: 'Years',
        valueType: 'DateTime',
        edgeLabelPlacement: 'Shift'
    },
    primaryYAxis: {
        title: 'Percentage (%)',
        minimum: 0, 
        maximum: 20, 
        interval: 4,
        labelFormat: '{value}%'
    },
    series: [
        {
            type: 'StepLine',
            dataSource: chartData, xName: 'x', yName: 'y',
            width: 2, name: 'China',
            marker: { visible: true, width: 10, height: 10 }
        },
        {
            type: 'StepLine',
            dataSource: chartData, xName: 'x', yName: 'y1',
            width: 2, name: 'Australia',
            marker: { visible: true, width: 10, height: 10 }
        },
        {
            type: 'StepLine',
            dataSource: chartData, xName: 'x', yName: 'y2',
            width: 2, name: 'Japan',
            marker: { visible: true, width: 10, height: 10 }
        }
    ],
    title: 'Unemployment Rates 1975-2010',
    legendSettings: { visible: true },
    tooltip: { enable: true, enableHighlight: 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>

Customize the appearance of tooltip

The fill and border properties are used to customize the background color and border of the tooltip respectively. The textStyle property in the tooltip is used to customize the font of the tooltip text. The highlightColor property is used to customize the point color while hovering for tooltip.

import { Chart, StepLineSeries, DateTime, Legend, Tooltip } from '@syncfusion/ej2-charts';
import { chartData } from './datasource.ts';
Chart.Inject(StepLineSeries, DateTime, Legend, Tooltip);

let chart: Chart = new Chart({
        primaryXAxis: {
            valueType: 'DateTime',
        },
        //Highlight color for tooltip
        highlightColor: 'red',
        series: [
            {
                type: 'StepLine',
                dataSource: chartData, xName: 'x', yName: 'y',
                width: 2, name: 'China',
                marker: {
                    visible: true, width: 10, height: 10
                },
            }
        ],
        title: 'Unemployment Rates 1975-2010',
        tooltip: {
            enable: true,
            format: '${series.name} ${point.x} : ${point.y}',
            //fill for tooltip
            fill: '#7bb4eb',
            //border for tooltip
            border: {
                width: 2,
                color: 'grey'
            }
        }
}, '#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>
     <script id="Unemployment" type="text/x-template">
      <div id='templateWrap'>
     <table style="width:100%;  border: 1px solid black;">
     <tr><th colspan="2" bgcolor="#00FFFF">Unemployment</th></tr>
     <tr><td bgcolor="#00FFFF">${x}:</td><td bgcolor="#00FFFF">${y}</td></tr>
    </table>
    </div>
  </script>
</body>

</html>

See also