Tooltip in Angular Chart component

3 Feb 202624 minutes to read

The chart displays detailed information about a data point through a tooltip when the mouse pointer moves over the point.

Default tooltip

By default, the tooltip is not visible. You can enable the tooltip by setting the enable property to true and by injecting TooltipService into the NgModule.providers.

To known about tooltip, you can check on this video:

app.component.ts

import { NgModule } from '@angular/core'
import { BrowserModule } from '@angular/platform-browser'
import { ChartModule} from '@syncfusion/ej2-angular-charts'
import { DateTimeService, StepLineSeriesService, ColumnSeriesService } from '@syncfusion/ej2-angular-charts'
import { LegendService, TooltipService, CategoryService } from '@syncfusion/ej2-angular-charts'



import { Component, OnInit } from '@angular/core';
import { toolData } from './datasource';
@Component({
imports: [
         ChartModule
    ],

providers: [ DateTimeService, StepLineSeriesService, LegendService, TooltipService, CategoryService, ColumnSeriesService],
standalone: true,
    selector: 'app-container',
    template: `<ejs-chart id="chart-container" [primaryXAxis]='primaryXAxis'[primaryYAxis]='primaryYAxis' [title]='title' [tooltip]='tooltip'>
        <e-series-collection>
            <e-series [dataSource]='chartData' type='StepLine' xName='x' yName='y' width=2 name='China' [marker]='marker'></e-series>
        </e-series-collection>
    </ejs-chart>`
})
export class AppComponent implements OnInit {
    public primaryXAxis?: Object;
    public chartData?: Object[];
    public title?: string;
    public primaryYAxis?: Object;
    public marker?: Object;
    public tooltip?: Object;
    ngOnInit(): void {
        this.chartData = toolData;
        this.primaryXAxis = {
            valueType: 'DateTime',
        };
        this.tooltip = { enable: true };
        this.marker = { visible: true, width: 10, height: 10 };
        this.title = 'Unemployment Rates 1975-2010';

}
}

main.ts

import { bootstrapApplication } from '@angular/platform-browser';
import { AppComponent } from './app.component';
import 'zone.js';
bootstrapApplication(AppComponent).catch((err) => console.error(err));

Fixed tooltip

By default, the tooltip tracks the mouse movement. You can render the tooltip at a fixed position by using the location property.

app.component.ts

import { NgModule } from '@angular/core'
import { BrowserModule } from '@angular/platform-browser'
import { ChartModule} from '@syncfusion/ej2-angular-charts'
import { DateTimeService, StepLineSeriesService, ColumnSeriesService } from '@syncfusion/ej2-angular-charts'
import { LegendService, TooltipService, CategoryService } from '@syncfusion/ej2-angular-charts'



import { Component, OnInit } from '@angular/core';
import { toolData } from './datasource';
@Component({
imports: [
         ChartModule
    ],

providers: [ DateTimeService, StepLineSeriesService, LegendService, TooltipService, CategoryService, ColumnSeriesService],
standalone: true,
    selector: 'app-container',
    template: `<ejs-chart id="chart-container" [primaryXAxis]='primaryXAxis'[primaryYAxis]='primaryYAxis' [title]='title' [tooltip]='tooltip'>
        <e-series-collection>
            <e-series [dataSource]='chartData' type='StepLine' xName='x' yName='y' width=2 name='China' [marker]='marker'></e-series>
        </e-series-collection>
    </ejs-chart>`
})
export class AppComponent implements OnInit {
    public primaryXAxis?: Object;
    public chartData?: Object[];
    public title?: string;
    public primaryYAxis?: Object;
    public marker?: Object;
    public tooltip?: Object;
    ngOnInit(): void {
        this.chartData = toolData;
        this.primaryXAxis = {
            valueType: 'DateTime',
        };
        this.tooltip = { enable: true, location: { x: 120, y: 20 } };
        this.marker = { visible: true, width: 10, height: 10 };
        this.title = 'Unemployment Rates 1975-2010';

}
}

main.ts

import { bootstrapApplication } from '@angular/platform-browser';
import { AppComponent } from './app.component';
import 'zone.js';
bootstrapApplication(AppComponent).catch((err) => console.error(err));

Format the tooltip

By default, the tooltip displays the x- and y-values of a data point. Additional information can be shown by specifying a custom format. For example, the format ${series.name} ${point.x} displays the series name along with the x-value of the data point.

app.component.ts

import { NgModule } from '@angular/core'
import { BrowserModule } from '@angular/platform-browser'
import { ChartModule} from '@syncfusion/ej2-angular-charts'
import { DateTimeService, StepLineSeriesService, ColumnSeriesService } from '@syncfusion/ej2-angular-charts'
import { LegendService, TooltipService, CategoryService } from '@syncfusion/ej2-angular-charts'



import { Component, OnInit } from '@angular/core';
import { toolData } from './datasource';
@Component({
imports: [
         ChartModule
    ],

providers: [ DateTimeService, StepLineSeriesService, LegendService, TooltipService, CategoryService, ColumnSeriesService],
standalone: true,
    selector: 'app-container',
    template: `<ejs-chart id="chart-container" [primaryXAxis]='primaryXAxis'[primaryYAxis]='primaryYAxis' [title]='title' [tooltip]='tooltip'>
        <e-series-collection>
            <e-series [dataSource]='chartData' type='StepLine' xName='x' yName='y' width=2 name='China' [marker]='marker'></e-series>
        </e-series-collection>
    </ejs-chart>`
})
export class AppComponent implements OnInit {
    public primaryXAxis?: Object;
    public chartData?: Object[];
    public title?: string;
    public marker?: Object;
    public tooltip?: Object;
primaryYAxis: any;
    ngOnInit(): void {
        this.chartData = toolData;
        this.primaryXAxis = {
            valueType: 'DateTime'
        };
        this.tooltip = { enable: true, header: 'Unemployment', format: '<b>${point.x} : ${point.y}</b>' };
        this.marker = { visible: true, width: 10, height: 10 };
        this.title = 'Unemployment Rates 1975-2010';

}
}

main.ts

import { bootstrapApplication } from '@angular/platform-browser';
import { AppComponent } from './app.component';
import 'zone.js';
bootstrapApplication(AppComponent).catch((err) => console.error(err));

Individual series format

Each series tooltip can be formatted separately by using the series tooltipFormat property.

Note: When the series tooltipFormat property is specified, the tooltip for that series is displayed in the defined format. Otherwise, the global tooltip format is applied.

app.component.ts

import { NgModule } from '@angular/core'
import { BrowserModule } from '@angular/platform-browser'
import { ChartModule} from '@syncfusion/ej2-angular-charts'
import { DateTimeService, StepLineSeriesService, ColumnSeriesService } from '@syncfusion/ej2-angular-charts'
import { LegendService, TooltipService, CategoryService } from '@syncfusion/ej2-angular-charts'

import { Component, OnInit } from '@angular/core';
import { toolData } from './datasource';
@Component({
imports: [
         ChartModule
    ],

providers: [ DateTimeService, StepLineSeriesService, LegendService, TooltipService, CategoryService, ColumnSeriesService],
standalone: true,
    selector: 'app-container',
    template: `<ejs-chart id="chart-container" [primaryXAxis]='primaryXAxis' [title]='title' [tooltip]='tooltip'>
        <e-series-collection>
            <e-series [dataSource]='chartData' type='StepLine' xName='x' yName='y' width=2 name='China' [marker]='marker' [tooltipFormat]="tooltipFormat"></e-series>
            <e-series [dataSource]='chartData' type='StepLine' xName='x' yName='y1' width=2 name='China' [marker]='marker'></e-series>
        </e-series-collection>
    </ejs-chart>`
})
export class AppComponent implements OnInit {
    public primaryXAxis?: Object;
    public chartData?: Object[];
    public title?: string;
    public marker?: Object;
    public tooltip?: Object;
    public tooltipFormat?: string;
    ngOnInit(): void {
      this.chartData = toolData;
        this.primaryXAxis = {
            valueType: 'DateTime'
        };
        this.tooltip = { enable: true, header: 'Unemployment', format: '<b>${point.x} : ${point.y}</b>' };
        this.marker = { visible: true, width: 10, height: 10 };
        this.title = 'Unemployment Rates 1975-2010';
        this.tooltipFormat = '${point.x}';

}
}

main.ts

import { bootstrapApplication } from '@angular/platform-browser';
import { AppComponent } from './app.component';
import 'zone.js';
bootstrapApplication(AppComponent).catch((err) => console.error(err));

Tooltip template

Custom HTML content can be rendered in the tooltip by using the template property. The ${x} and ${y} placeholders can be used within the template to display the x- and y-values of the corresponding data point.

app.component.ts

import { NgModule } from '@angular/core'
import { BrowserModule } from '@angular/platform-browser'
import { ChartModule} from '@syncfusion/ej2-angular-charts'
import { DateTimeService, StepLineSeriesService, ColumnSeriesService } from '@syncfusion/ej2-angular-charts'
import { LegendService, TooltipService, CategoryService } from '@syncfusion/ej2-angular-charts'



import { Component, OnInit } from '@angular/core';
import { toolData } from './datasource';
@Component({
imports: [
         ChartModule
    ],

providers: [ DateTimeService, StepLineSeriesService, LegendService, TooltipService, CategoryService, ColumnSeriesService],
standalone: true,
    selector: 'app-container',
    template: `<ejs-chart id="chart-container" [primaryXAxis]='primaryXAxis'[primaryYAxis]='primaryYAxis' [title]='title' [tooltip]='tooltip'>
        <e-series-collection>
            <e-series [dataSource]='chartData' type='StepLine' xName='x' yName='y' width=2 name='China' [marker]='marker'></e-series>
        </e-series-collection>
    </ejs-chart>`
})
export class AppComponent implements OnInit {
    public primaryXAxis?: Object;
    public chartData?: Object[];
    public title?: string;
    public primaryYAxis?: Object;
    public marker?: Object;
    public tooltip?: Object;
    ngOnInit(): void {
        this.chartData = toolData;
        this.primaryXAxis = {
            valueType: 'DateTime'
        };
        this.tooltip = { enable: true, template: '#Unemployment' };
        this.marker = { visible: true, width: 10, height: 10 };
        this.title = 'Unemployment Rates 1975-2010';
    }
}

main.ts

import { bootstrapApplication } from '@angular/platform-browser';
import { AppComponent } from './app.component';
import 'zone.js';
bootstrapApplication(AppComponent).catch((err) => console.error(err));

Enable highlight

By setting the enableHighlight property to true, all points in the hovered series are highlighted while the remaining points are dimmed. This behavior improves focus and readability during data analysis.

app.component.ts

import { ChartModule } from '@syncfusion/ej2-angular-charts';
import { DateTimeService, StepLineSeriesService, LegendService, TooltipService } from '@syncfusion/ej2-angular-charts';
import { Component, OnInit } from '@angular/core';
import { chartData } from './datasource';
@Component({
    imports: [ChartModule],
    providers: [DateTimeService, StepLineSeriesService, LegendService, TooltipService],
    standalone: true,
    selector: 'app-container',
    template: `<ejs-chart id="chart-container" [primaryXAxis]='primaryXAxis'[primaryYAxis]='primaryYAxis' [title]='title' [legendSettings]='legendSettings' [tooltip]='tooltip'>
        <e-series-collection>
            <e-series [dataSource]='chartData' type='StepLine' xName='x' yName='y' width=2 name='China' [marker]='marker'></e-series>
            <e-series [dataSource]='chartData' type='StepLine' xName='x' yName='y1' width=2 name='Australia' [marker]='marker'></e-series>
            <e-series [dataSource]='chartData' type='StepLine' xName='x' yName='y2' width=2 name='Japan' [marker]='marker'></e-series>
        </e-series-collection>
    </ejs-chart>`
})
export class AppComponent implements OnInit {
    public primaryXAxis?: Object;
    public primaryYAxis?: Object;
    public chartData?: Object[];
    public title?: string;
    public marker?: Object;
    public tooltip?: Object;
    public legendSettings?: Object;
    ngOnInit(): void {
        this.chartData = chartData;
        this.primaryXAxis = {
            title: 'Years',
            lineStyle: { width: 0 },
            labelFormat: 'y',
            intervalType: 'Years',
            valueType: 'DateTime',
            edgeLabelPlacement: 'Shift'
        };
        this.primaryYAxis = {
            title: 'Percentage (%)',
            minimum: 0,
            maximum: 20,
            interval: 4,
            labelFormat: '{value}%'
        };
        this.tooltip = { enable: true, enableHighlight: true };
        this.marker = { visible: true, width: 10, height: 10 };
        this.title = 'Unemployment Rates 1975-2010';
        this.legendSettings = { visible: true };
    }
}

main.ts

import { bootstrapApplication } from '@angular/platform-browser';
import { AppComponent } from './app.component';
import 'zone.js';
bootstrapApplication(AppComponent).catch((err) => console.error(err));

Tooltip mapping name

By default, the tooltip displays only the x- and y-values of a data point. Additional information from the data source can be shown by using the tooltipMappingName property of the series. Use the ${point.tooltip} placeholder in the tooltip format to display the mapped value.

app.component.ts

import { NgModule } from '@angular/core'
import { BrowserModule } from '@angular/platform-browser'
import { ChartModule} from '@syncfusion/ej2-angular-charts'
import { DateTimeService, StepLineSeriesService, ColumnSeriesService } from '@syncfusion/ej2-angular-charts'
import { LegendService, TooltipService, CategoryService } from '@syncfusion/ej2-angular-charts'



import { Component, OnInit } from '@angular/core';
import { toolData } from './datasource';
@Component({
imports: [
         ChartModule
    ],

providers: [ DateTimeService, StepLineSeriesService, LegendService, TooltipService, CategoryService, ColumnSeriesService],
standalone: true,
    selector: 'app-container',
    template: `<ejs-chart id="chart-container" [primaryXAxis]='primaryXAxis' [title]='title' [tooltip]='tooltip'>
        <e-series-collection>
            <e-series [dataSource]='chartData' type='Column' xName='x' yName='y' width=2 tooltipMappingName='country'></e-series>
        </e-series-collection>
    </ejs-chart>`
})
export class AppComponent implements OnInit {
    public primaryXAxis?: Object;
    public chartData?: Object[];
    public title?: string;
    public tooltip?: Object;
    ngOnInit(): void {
        this.chartData =  [
                    { x: 'Germany', y: 72, country: 'GER: 72'},
                    { x: 'Russia', y: 103.1, country: 'RUS: 103.1'},
                    { x: 'Brazil', y: 139.1, country: 'BRZ: 139.1'},
                    { x: 'India', y: 462.1, country: 'IND: 462.1'},
                    { x: 'China', y: 721.4, country: 'CHN: 721.4'},
                    { x: 'United States Of America', y: 286.9, country: 'USA: 286.9'},
                    { x: 'Great Britain', y: 115.1, country: 'GBR: 115.1'},
                    { x: 'Nigeria', y: 97.2, country: 'NGR: 97.2'},
        ];
        this.primaryXAxis = {
             valueType: 'Category',
        };
        this.tooltip = {
               enable: true, format: '${point.tooltip}'
        };
        this.title = 'Internet Users in Million – 2016';

}


}

main.ts

import { bootstrapApplication } from '@angular/platform-browser';
import { AppComponent } from './app.component';
import 'zone.js';
bootstrapApplication(AppComponent).catch((err) => console.error(err));

Customize the appearance of tooltip

The appearance of the tooltip can be customized by using the following properties:

• fill to set the background color
• border to configure the tooltip border
• textStyle to customize the tooltip text style
  The highlightColor property is used to change the color of a data point when it is highlighted during tooltip interaction.

app.component.ts

import { NgModule } from '@angular/core'
import { BrowserModule } from '@angular/platform-browser'
import { ChartModule} from '@syncfusion/ej2-angular-charts'
import { DateTimeService, StepLineSeriesService, ColumnSeriesService } from '@syncfusion/ej2-angular-charts'
import { LegendService, TooltipService, CategoryService } from '@syncfusion/ej2-angular-charts'



import { Component, OnInit } from '@angular/core';
import { toolData } from './datasource';
@Component({
imports: [
         ChartModule
    ],

providers: [ DateTimeService, StepLineSeriesService, LegendService, TooltipService, CategoryService, ColumnSeriesService],
standalone: true,
    selector: 'app-container',
    template: `<ejs-chart id="chart-container" highlightColor="red" [primaryXAxis]='primaryXAxis'[primaryYAxis]='primaryYAxis' [title]='title' [tooltip]='tooltip'>
        <e-series-collection>
            <e-series [dataSource]='chartData' type='StepLine' xName='x' yName='y' width=2 name='China' [marker]='marker'></e-series>
        </e-series-collection>
    </ejs-chart>`
})
export class AppComponent implements OnInit {
    public primaryXAxis?: Object;
    public chartData?: Object[];
    public title?: string;
    public primaryYAxis?: Object;
    public marker?: Object;
    public tooltip?: Object;
    ngOnInit(): void {
        this.chartData = toolData;
        this.primaryXAxis = {
            valueType: 'DateTime'
        };
        this.tooltip = {
                enable: true,
                format: '${series.name} ${point.x} : ${point.y}',
                fill: '#7bb4eb',
                border: {
                   width: 2,
                   color: 'grey'
                }
        };
        this.marker = { visible: true, width: 10, height: 10 };
        this.title = 'Unemployment Rates 1975-2010';
    }
}

main.ts

import { bootstrapApplication } from '@angular/platform-browser';
import { AppComponent } from './app.component';
import 'zone.js';
bootstrapApplication(AppComponent).catch((err) => console.error(err));

Closest tooltip

The showNearestTooltip property displays the tooltip for the data point nearest to the pointer, even when the pointer is not directly positioned over the point.

app.component.ts

import { ChartModule } from '@syncfusion/ej2-angular-charts';
import { DateTimeService, StepLineSeriesService, LegendService, TooltipService } from '@syncfusion/ej2-angular-charts';
import { Component, OnInit } from '@angular/core';
import { chartData } from './datasource';
@Component({
    imports: [ChartModule],
    providers: [DateTimeService, StepLineSeriesService, LegendService, TooltipService],
    standalone: true,
    selector: 'app-container',
    template: `<ejs-chart id="chart-container" [primaryXAxis]='primaryXAxis'[primaryYAxis]='primaryYAxis' [title]='title' [legendSettings]='legendSettings' [tooltip]='tooltip'>
        <e-series-collection>
            <e-series [dataSource]='chartData' type='StepLine' xName='x' yName='y' width=2 name='China' [marker]='marker'></e-series>
            <e-series [dataSource]='chartData' type='StepLine' xName='x' yName='y1' width=2 name='Australia' [marker]='marker'></e-series>
            <e-series [dataSource]='chartData' type='StepLine' xName='x' yName='y2' width=2 name='Japan' [marker]='marker'></e-series>
        </e-series-collection>
    </ejs-chart>`
})
export class AppComponent implements OnInit {
    public primaryXAxis?: Object;
    public primaryYAxis?: Object;
    public chartData?: Object[];
    public title?: string;
    public marker?: Object;
    public tooltip?: Object;
    public legendSettings?: Object;
    ngOnInit(): void {
        this.chartData = chartData;
        this.primaryXAxis = {
            title: 'Years',
            lineStyle: { width: 0 },
            labelFormat: 'y',
            intervalType: 'Years',
            valueType: 'DateTime',
            edgeLabelPlacement: 'Shift'
        };
        this.primaryYAxis = {
            title: 'Percentage (%)',
            minimum: 0,
            maximum: 20,
            interval: 4,
            labelFormat: '{value}%'
        };
        this.tooltip = { enable: true, enableHighlight: true, showNearestTooltip: true };
        this.marker = { visible: true, width: 10, height: 10 };
        this.title = 'Unemployment Rates 1975-2010';
        this.legendSettings = { visible: true };
    }
}

main.ts

import { bootstrapApplication } from '@angular/platform-browser';
import { AppComponent } from './app.component';
import 'zone.js';
bootstrapApplication(AppComponent).catch((err) => console.error(err));

See Also

• Format the tooltip value
• Create a table in tooltip
• Hide Tooltip for Truncated Data Labels
• Hide Tooltips for Truncated Axis Labels