Grouping in Angular Drop down list component

27 Apr 20244 minutes to read

The DropDownList supports wrapping nested elements into a group based on different categories. The category of each list item can be mapped through the groupBy field in the data table. The group header is displayed both as inline and fixed headers. The fixed group header content is updated dynamically on scrolling the popup list with its category value.

To get started quickly with grouping in angular DropDownList component, you can check the video below.

In the following sample, vegetables are grouped according on its category using groupBy field.

import { NgModule } from '@angular/core'
import { BrowserModule } from '@angular/platform-browser'
import { FormsModule, ReactiveFormsModule } from '@angular/forms'
import { DropDownListModule } from '@syncfusion/ej2-angular-dropdowns'
import { ButtonModule } from '@syncfusion/ej2-angular-buttons'



import { Component } from '@angular/core';

@Component({
imports: [
        FormsModule, ReactiveFormsModule, DropDownListModule, ButtonModule
    ],


standalone: true,
    selector: 'app-root',
    // specifies the template string for the DropDownList component
    template: `<ejs-dropdownlist id='ddlelement' #samples [dataSource]='data' [fields]='fields' [placeholder]='text' [popupHeight]='height'></ejs-dropdownlist>`
})
export class AppComponent {
    constructor() {
    }
    // defined the array of data
    public data: { [key: string]: Object }[] = [
        { Vegetable: 'Cabbage', Category: 'Leafy and Salad', Id: 'item1' },
        { Vegetable: 'Spinach', Category: 'Leafy and Salad', Id: 'item2' },
        { Vegetable: 'Wheat grass', Category: 'Leafy and Salad', Id: 'item3' },
        { Vegetable: 'Yarrow', Category: 'Leafy and Salad', Id: 'item4' },
        { Vegetable: 'Pumpkins', Category: 'Leafy and Salad', Id: 'item5' },
        { Vegetable: 'Chickpea', Category: 'Beans', Id: 'item6' },
        { Vegetable: 'Green bean', Category: 'Beans', Id: 'item7' },
        { Vegetable: 'Horse gram', Category: 'Beans', Id: 'item8' },
        { Vegetable: 'Garlic', Category: 'Bulb and Stem', Id: 'item9' },
        { Vegetable: 'Nopal', Category: 'Bulb and Stem', Id: 'item10' },
        { Vegetable: 'Onion', Category: 'Bulb and Stem', Id: 'item11' }];
    // maps the appropriate column to fields property
    public fields: Object = { groupBy: 'Category', text: 'Vegetable', value: 'Id' };
    // set the placeholder to the DropDownList input
    public text: string = "Select a vegetable";
    // Set the popup list height
    public height: string = '200px';
}
import { bootstrapApplication } from '@angular/platform-browser';
import { AppComponent } from './app.component';
import 'zone.js';
bootstrapApplication(AppComponent).catch((err) => console.error(err));

Customization

The grouping header is also provided with customization option. This allows custom designing using the groupTemplate property for both inline and fixed headers.

See Also