Data labels in Angular Chart component

18 Nov 202224 minutes to read

Data label can be added to a chart series by enabling the visible option in the dataLabel. By default, the labels will arrange smartly without overlapping.

import { Component, OnInit } from '@angular/core';
import { columnData } from 'datasource.ts';
@Component({
    selector: 'app-container',
    template:
    `<ejs-chart id="chart-container" [primaryXAxis]='primaryXAxis'[primaryYAxis]='primaryYAxis' [title]='title'>
        <e-series-collection>
            <e-series [dataSource]='chartData' type='Column' xName='x' yName='y' name='Warmest' width=2 [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;
    ngOnInit(): void {
        this.chartData = columnData;
        this.primaryXAxis = {
            valueType: 'Category'
        };
        this.marker = { dataLabel: { visible: true }
        };
        this.title = 'Alaska Weather Statistics - 2016';
    }

}
import { NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { AppComponent } from './app.component';
import { ChartModule } from '@syncfusion/ej2-angular-charts';
import { DateTimeService, CategoryService, LineSeriesService, ColumnSeriesService } from '@syncfusion/ej2-angular-charts';
import { LegendService, DataLabelService } from '@syncfusion/ej2-angular-charts';

/**
 * Module
 */
@NgModule({
    imports: [
        BrowserModule, ChartModule
    ], 
    declarations: [AppComponent],
    bootstrap: [AppComponent],
    providers: [ DateTimeService, LineSeriesService, LegendService, DataLabelService, ColumnSeriesService, CategoryService ]
})
export class AppModule { }
import { platformBrowserDynamic } from '@angular/platform-browser-dynamic';
import { enableProdMode } from '@angular/core';
import { AppModule } from './app.module';

enableProdMode();
platformBrowserDynamic().bootstrapModule(AppModule);

Note: To use datalabel feature, we need to inject DataLabelService into the @NgModule.providers.

Position

Using position property, you can place the label either on
Top, Middle,Bottom or Outer (outer is applicable for column and bar type series).

import { Component, OnInit } from '@angular/core';
import { columnData } from 'datasource.ts';
@Component({
    selector: 'app-container',
    template:
    `<ejs-chart id="chart-container" [primaryXAxis]='primaryXAxis'[primaryYAxis]='primaryYAxis' [title]='title'>
        <e-series-collection>
            <e-series [dataSource]='chartData' type='Column' xName='x' yName='y' name='Warmest' width=2 [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;
    ngOnInit(): void {
        this.chartData = columnData;
        this.primaryXAxis = {
            valueType: 'Category'
        };
        this.marker = { dataLabel: { visible: true, position: 'Middle' }
        };
        this.title = 'Alaska Weather Statistics - 2016';
    }

}
import { NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { AppComponent } from './app.component';
import { ChartModule } from '@syncfusion/ej2-angular-charts';
import { DateTimeService, CategoryService, LineSeriesService, ColumnSeriesService } from '@syncfusion/ej2-angular-charts';
import { LegendService, DataLabelService } from '@syncfusion/ej2-angular-charts';

/**
 * Module
 */
@NgModule({
    imports: [
        BrowserModule, ChartModule
    ], 
    declarations: [AppComponent],
    bootstrap: [AppComponent],
    providers: [ DateTimeService, LineSeriesService, LegendService, DataLabelService, ColumnSeriesService, CategoryService ]
})
export class AppModule { }
import { platformBrowserDynamic } from '@angular/platform-browser-dynamic';
import { enableProdMode } from '@angular/core';
import { AppModule } from './app.module';

enableProdMode();
platformBrowserDynamic().bootstrapModule(AppModule);

Note: The position Outer is applicable for column and bar type series.

Data Label Template

Label content can be formatted by using the template option. Inside the template, you can add the placeholder text ${point.x} and ${point.y} to display corresponding data points x & y value.
Using template property, you can set data label template in chart.

import { Component, OnInit } from '@angular/core';
import { columnData } from 'datasource.ts';
@Component({
    selector: 'app-container',
    template:
    `<ejs-chart id="chart-container" [primaryXAxis]='primaryXAxis'[primaryYAxis]='primaryYAxis' [title]='title'>
        <e-series-collection>
            <e-series [dataSource]='chartData' type='Column' xName='x' yName='y' name='Warmest' width=2 [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;
    ngOnInit(): void {
        this.chartData = columnData;
        this.primaryXAxis = {
            title: 'Months',
            valueType: 'Category', labelFormat: 'yMMM',
            edgeLabelPlacement: 'Shift'
        };
        this.marker = { dataLabel: { visible: true, position: 'Middle',
                        template: '<div>${point.x}</div><div>${point.y}</div>' }
        };
        this.title = 'Alaska Weather Statistics - 2016';
    }

}
import { NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { AppComponent } from './app.component';
import { ChartModule } from '@syncfusion/ej2-angular-charts';
import { DateTimeService, CategoryService, LineSeriesService, ColumnSeriesService } from '@syncfusion/ej2-angular-charts';
import { LegendService, DataLabelService } from '@syncfusion/ej2-angular-charts';

/**
 * Module
 */
@NgModule({
    imports: [
        BrowserModule, ChartModule
    ], 
    declarations: [AppComponent],
    bootstrap: [AppComponent],
    providers: [ DateTimeService, LineSeriesService, LegendService, DataLabelService, ColumnSeriesService, CategoryService ]
})
export class AppModule { }
import { platformBrowserDynamic } from '@angular/platform-browser-dynamic';
import { enableProdMode } from '@angular/core';
import { AppModule } from './app.module';

enableProdMode();
platformBrowserDynamic().bootstrapModule(AppModule);

Format

Data label for the chart can be formatted using format property. You can use the global formatting options, such as ‘n’, ‘p’, and ‘c’.

import { Component, OnInit } from '@angular/core';
import { columnData } from 'datasource.ts';
@Component({
    selector: 'app-container',
    template:
    `<ejs-chart id="chart-container" [primaryXAxis]='primaryXAxis'[primaryYAxis]='primaryYAxis' [title]='title'>
        <e-series-collection>
            <e-series [dataSource]='chartData' type='Column' xName='x' yName='y' name='Warmest' width=2 [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;
    ngOnInit(): void {
        this.chartData = columnData;
        this.primaryXAxis = {
            title: 'Months',
            valueType: 'Category', labelFormat: 'yMMM',
            edgeLabelPlacement: 'Shift'
        };
        this.marker = { dataLabel: { visible: true, format: 'p1'}
        };
        this.title = 'Alaska Weather Statistics - 2016';
    }

}
import { NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { AppComponent } from './app.component';
import { ChartModule } from '@syncfusion/ej2-angular-charts';
import { DateTimeService, CategoryService, LineSeriesService, ColumnSeriesService } from '@syncfusion/ej2-angular-charts';
import { LegendService, DataLabelService } from '@syncfusion/ej2-angular-charts';

/**
 * Module
 */
@NgModule({
    imports: [
        BrowserModule, ChartModule
    ], 
    declarations: [AppComponent],
    bootstrap: [AppComponent],
    providers: [ DateTimeService, LineSeriesService, LegendService, DataLabelService, ColumnSeriesService, CategoryService ]
})
export class AppModule { }
import { platformBrowserDynamic } from '@angular/platform-browser-dynamic';
import { enableProdMode } from '@angular/core';
import { AppModule } from './app.module';

enableProdMode();
platformBrowserDynamic().bootstrapModule(AppModule);

Value Format Resultant Value Description
1000 n1 1000.0 The number is rounded to 1 decimal place.
1000 n2 1000.00 The number is rounded to 2 decimal places.
1000 n3 1000.000 The number is rounded to 3 decimal place.
0.01 p1 1.0% The number is converted to percentage with 1 decimal place.
0.01 p2 1.00% The number is converted to percentage with 2 decimal place.
0.01 p3 1.000% The number is converted to percentage with 3 decimal place.
1000 c1 $1000.0 The currency symbol is appended to number and number is rounded to 1 decimal place.
1000 c2 $1000.00 The currency symbol is appended to number and number is rounded to 2 decimal place.

Text Mapping

Text from the data source can be mapped using name property.

import { Component, OnInit } from '@angular/core';
import { mapData } from 'datasource.ts';
@Component({
    selector: 'app-container',
    template:
    `<ejs-chart id="chart-container" [primaryXAxis]='primaryXAxis'[primaryYAxis]='primaryYAxis' [title]='title'>
        <e-series-collection>
            <e-series [dataSource]='chartData' type='Column' xName='x' yName='y' name='Warmest' width=2 [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;
    ngOnInit(): void {
        this.chartData = mapData;
        this.primaryXAxis = {
            valueType: 'Category'
        };
        this.marker = { dataLabel: { visible: true, name: 'text'}
        };
        this.title = 'Alaska Weather Statistics - 2016';
    }

}
import { NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { AppComponent } from './app.component';
import { ChartModule } from '@syncfusion/ej2-angular-charts';
import { DateTimeService, CategoryService, LineSeriesService, ColumnSeriesService } from '@syncfusion/ej2-angular-charts';
import { LegendService, DataLabelService } from '@syncfusion/ej2-angular-charts';

/**
 * Module
 */
@NgModule({
    imports: [
        BrowserModule, ChartModule
    ], 
    declarations: [AppComponent],
    bootstrap: [AppComponent],
    providers: [ DateTimeService, LineSeriesService, LegendService, DataLabelService, ColumnSeriesService, CategoryService ]
})
export class AppModule { }
import { platformBrowserDynamic } from '@angular/platform-browser-dynamic';
import { enableProdMode } from '@angular/core';
import { AppModule } from './app.module';

enableProdMode();
platformBrowserDynamic().bootstrapModule(AppModule);

Margin

margin for data label can be applied to using left, right, bottom and top properties.

import { Component, OnInit } from '@angular/core';
import { columnData } from 'datasource.ts';
@Component({
    selector: 'app-container',
    template:
    `<ejs-chart id="chart-container" [primaryXAxis]='primaryXAxis'[primaryYAxis]='primaryYAxis' [title]='title'>
        <e-series-collection>
            <e-series [dataSource]='chartData' type='Column' xName='x' yName='y' name='Warmest' width=2 [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;
    ngOnInit(): void {
        this.chartData = columnData;
        this.primaryXAxis = {
            valueType: 'Category'
        };
        this.marker = { dataLabel: { visible: true,border:{width: 1, color : 'red'},
                        margin:{
                            left:5,
                            right:5,
                            top:5,
                            bottom:5
                        } }
        };
        this.title = 'Alaska Weather Statistics - 2016';
    }

}
import { NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { AppComponent } from './app.component';
import { ChartModule } from '@syncfusion/ej2-angular-charts';
import { DateTimeService, CategoryService, LineSeriesService, ColumnSeriesService } from '@syncfusion/ej2-angular-charts';
import { LegendService, DataLabelService } from '@syncfusion/ej2-angular-charts';

/**
 * Module
 */
@NgModule({
    imports: [
        BrowserModule, ChartModule
    ], 
    declarations: [AppComponent],
    bootstrap: [AppComponent],
    providers: [ DateTimeService, LineSeriesService, LegendService, DataLabelService, ColumnSeriesService, CategoryService ]
})
export class AppModule { }
import { platformBrowserDynamic } from '@angular/platform-browser-dynamic';
import { enableProdMode } from '@angular/core';
import { AppModule } from './app.module';

enableProdMode();
platformBrowserDynamic().bootstrapModule(AppModule);

DataLabel Rotation

Using angle property, you can rotate the data label by its given angle.

import { Component, OnInit } from '@angular/core';
import { columnData } from 'datasource.ts';
@Component({
    selector: 'app-container',
    template:
    `<ejs-chart id="chart-container" [primaryXAxis]='primaryXAxis'[primaryYAxis]='primaryYAxis' [title]='title'>
        <e-series-collection>
            <e-series [dataSource]='chartData' type='Column' xName='x' yName='y' name='Warmest' width=2 [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;
    ngOnInit(): void {
        this.chartData = columnData;
        this.primaryXAxis = {
            valueType: 'Category'
        };
        this.marker = { dataLabel: { visible: true, border:{width: 1, color : 'red'},
                        margin:{
                            left:5,
                            right:5,
                            top:5,
                            bottom:5
                        }, angle : 45, enableRotation: true }
        };
        this.title = 'Alaska Weather Statistics - 2016';
    }
}
import { NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { AppComponent } from './app.component';
import { ChartModule } from '@syncfusion/ej2-angular-charts';
import { DateTimeService, CategoryService, LineSeriesService, ColumnSeriesService } from '@syncfusion/ej2-angular-charts';
import { LegendService, DataLabelService } from '@syncfusion/ej2-angular-charts';

/**
 * Module
 */
@NgModule({
    imports: [
        BrowserModule, ChartModule
    ], 
    declarations: [AppComponent],
    bootstrap: [AppComponent],
    providers: [ DateTimeService, LineSeriesService, LegendService, DataLabelService, ColumnSeriesService, CategoryService ]
})
export class AppModule { }
import { platformBrowserDynamic } from '@angular/platform-browser-dynamic';
import { enableProdMode } from '@angular/core';
import { AppModule } from './app.module';

enableProdMode();
platformBrowserDynamic().bootstrapModule(AppModule);

Customization

stroke and border of data label can be customized using fill and border properties. Rounded corners can be customized using rx and ry properties.

import { Component, OnInit } from '@angular/core';
import { columnData } from 'datasource.ts';
@Component({
    selector: 'app-container',
    template:
    `<ejs-chart id="chart-container" [primaryXAxis]='primaryXAxis'[primaryYAxis]='primaryYAxis' [title]='title'>
        <e-series-collection>
            <e-series [dataSource]='chartData' type='Column' xName='x' yName='y' name='Warmest' width=2 [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;
    ngOnInit(): void {
        this.chartData = columnData;
        this.primaryXAxis = {
            valueType: 'Category'
        };
        this.marker = { dataLabel: { visible: true,
                        border:{width: 2, color : 'red'},
                        rx:10, ry: 10
                    }
        };
        this.title = 'Alaska Weather Statistics - 2016';
    }

}
import { NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { AppComponent } from './app.component';
import { ChartModule } from '@syncfusion/ej2-angular-charts';
import { DateTimeService, CategoryService, LineSeriesService, ColumnSeriesService } from '@syncfusion/ej2-angular-charts';
import { LegendService, DataLabelService } from '@syncfusion/ej2-angular-charts';

/**
 * Module
 */
@NgModule({
    imports: [
        BrowserModule, ChartModule
    ], 
    declarations: [AppComponent],
    bootstrap: [AppComponent],
    providers: [ DateTimeService, LineSeriesService, LegendService, DataLabelService, ColumnSeriesService, CategoryService ]
})
export class AppModule { }
import { platformBrowserDynamic } from '@angular/platform-browser-dynamic';
import { enableProdMode } from '@angular/core';
import { AppModule } from './app.module';

enableProdMode();
platformBrowserDynamic().bootstrapModule(AppModule);

Note: rx and ry properties requires border values not to be null.

Customizing Specific Point

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

import { Component, OnInit } from '@angular/core';
import { IPointRenderEventArgs, ITextRenderEventArgs } from '@syncfusion/ej2-angular-charts';
import { columnData } from 'datasource.ts';
@Component({
    selector: 'app-container',
    template:
    `<ejs-chart id="chart-container" [primaryXAxis]='primaryXAxis'[primaryYAxis]='primaryYAxis' (pointRender)='pointRender($event)' (textRender)='textRender($event)'[title]='title'>
        <e-series-collection>
            <e-series [dataSource]='chartData' type='Column' xName='x' yName='y' name='Warmest' width=2 [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 pointRender(args: IPointRenderEventArgs): void {
        if(args.point.index === 6) {
                args.fill = 'red'
        }
    };
    public textRender(args: ITextRenderEventArgs): void {
            if(args.point.index === 6){
                args.text = 'Maximum Temperature';
                args.color = 'red';
            }
    };
    ngOnInit(): void {
        this.chartData = columnData;
        this.primaryXAxis = {
            title: 'Months',
            valueType: 'Category', labelFormat: 'yMMM',
            edgeLabelPlacement: 'Shift'
        };
        this.marker = { dataLabel: { visible: true }
        };
        this.title = 'Alaska Weather Statistics - 2016';
    }

}
import { NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { AppComponent } from './app.component';
import { ChartModule } from '@syncfusion/ej2-angular-charts';
import { DateTimeService, CategoryService, LineSeriesService, ColumnSeriesService } from '@syncfusion/ej2-angular-charts';
import { LegendService, DataLabelService } from '@syncfusion/ej2-angular-charts';

/**
 * Module
 */
@NgModule({
    imports: [
        BrowserModule, ChartModule
    ], 
    declarations: [AppComponent],
    bootstrap: [AppComponent],
    providers: [ DateTimeService, LineSeriesService, LegendService, DataLabelService, ColumnSeriesService, CategoryService ]
})
export class AppModule { }
import { platformBrowserDynamic } from '@angular/platform-browser-dynamic';
import { enableProdMode } from '@angular/core';
import { AppModule } from './app.module';

enableProdMode();
platformBrowserDynamic().bootstrapModule(AppModule);

Show percentage based on each series points

You can calculate the percentage value based on the sum for each series using the seriesRender and textRender events in the chart. In seriesRender calculate the sum of each series y values and In textRender calculate percentage value based on the sum value and modify the text.

import { Component, ViewEncapsulation } from '@angular/core';
import {
    ISeriesRenderEventArgs,
    ITextRenderEventArgs,
} from '@syncfusion/ej2-angular-charts';
import { Browser } from '@syncfusion/ej2-base';

let total: any = [];

/**
 * Sample for Column Series
 */
@Component({
    selector: 'app-container',
    template: `<div class="control-section">
    <div align='center'>
        <ejs-chart style='display:block;' [chartArea]='chartArea' [width]='width' align='center' id='chartcontainer' [primaryXAxis]='primaryXAxis'
            [primaryYAxis]='primaryYAxis' [title]='title' [tooltip]='tooltip' (seriesRender)='seriesRender($event)' (textRender)='textRender($event)'>
            <e-series-collection>
                <e-series [dataSource]='data' type='Column' xName='x' yName='y' name='Gold' width=2 [marker]='marker'> </e-series>
                <e-series [dataSource]='data1' type='Column' xName='x' yName='y' name='Silver' width=2 [marker]='marker'> </e-series>
                <e-series [dataSource]='data2' type='Column' xName='x' yName='y' name='Bronze' width=2 [marker]='marker'> </e-series>
            </e-series-collection>
        </ejs-chart>
    </div>
    <div style="float: right; margin-right: 10px; margin-top: -5px">Source:
        <a href="https://www.gov.uk/" target='_blank'>www.gov.uk</a>
    </div>
</div>`,
    encapsulation: ViewEncapsulation.None,
})
export class AppComponent {
    public data: Object[] = [
        { x: 'USA', y: 46 },
        { x: 'GBR', y: 27 },
        { x: 'CHN', y: 26 },
    ];
    public data1: Object[] = [
        { x: 'USA', y: 37 },
        { x: 'GBR', y: 23 },
        { x: 'CHN', y: 18 },
    ];
    public data2: Object[] = [
        { x: 'USA', y: 38 },
        { x: 'GBR', y: 17 },
        { x: 'CHN', y: 26 },
    ];
    //Initializing Primary X Axis
    public primaryXAxis: Object = {
        valueType: 'Category',
        interval: 1,
        majorGridLines: { width: 0 },
    };
    //Initializing Primary Y Axis
    public primaryYAxis: Object = {
        majorGridLines: { width: 0 },
        majorTickLines: { width: 0 },
        lineStyle: { width: 0 },
        labelStyle: { color: 'transparent' },
    };
    public marker: Object = {
        dataLabel: {
            visible: true,
            position: 'Top',
            font: { fontWeight: '600', color: '#ffffff' },
        },
    };
    public title: string = 'Olympic Medal Counts - RIO';
    public tooltip: Object = {
        enable: true,
    };
    // custom code start
    public seriesRender(args: ISeriesRenderEventArgs): void {
        for (let i = 0; i < args.data.length; i++) {
            if (!total[args.data[i].x]) total[args.data[i].x] = 0;
            total[args.data[i].x] += parseInt(args.data[i].y);
        }
    }
    public textRender(args: ITextRenderEventArgs): void {
        let percentage: number | string = (parseInt(args.text) / total[args.point.x]) * 100;
        percentage = percentage % 1 === 0 ? percentage : percentage.toFixed(2);
        args.text = percentage + '%';
    }
    // custom code end
    public chartArea: Object = {
        border: {
            width: 0,
        },
    };
    public width: string = Browser.isDevice ? '100%' : '60%';

    constructor() {
        //code
    }
}
import { NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { AppComponent } from './app.component';
import { ChartModule } from '@syncfusion/ej2-angular-charts';
import { DateTimeService, CategoryService, LineSeriesService, ColumnSeriesService } from '@syncfusion/ej2-angular-charts';
import { LegendService, DataLabelService } from '@syncfusion/ej2-angular-charts';

/**
 * Module
 */
@NgModule({
    imports: [
        BrowserModule, ChartModule
    ], 
    declarations: [AppComponent],
    bootstrap: [AppComponent],
    providers: [ DateTimeService, LineSeriesService, LegendService, DataLabelService, ColumnSeriesService, CategoryService ]
})
export class AppModule { }
import { platformBrowserDynamic } from '@angular/platform-browser-dynamic';
import { enableProdMode } from '@angular/core';
import { AppModule } from './app.module';

enableProdMode();
platformBrowserDynamic().bootstrapModule(AppModule);

See Also