Getting started with Angular Drop down list component

31 Jan 202411 minutes to read

This section briefly explains how to create a simple DropDownList component and configure its available functionalities in Angular.

Dependencies

The following list of dependencies are required to use the DropDownList component in your application.

|-- @syncfusion/ej2-angular-dropdowns
    |-- @syncfusion/ej2-base
    |-- @syncfusion/ej2-data
    |-- @syncfusion/ej2-angular-base
    |-- @syncfusion/ej2-dropdowns
        |-- @syncfusion/ej2-lists
        |-- @syncfusion/ej2-inputs
        |-- @syncfusion/ej2-navigations
        |-- @syncfusion/ej2-popups
            |-- @syncfusion/ej2-buttons

Setup angular environment

Angular provides the easiest way to set angular CLI projects using Angular CLI tool.

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

Install the CLI application globally to your machine.

npm install -g @angular/cli

Create a new application

ng new syncfusion-angular-dropdownlist

By default, it install the CSS style base application. To setup with SCSS, pass –style=scss argument on create project.

Example code snippet.

ng new syncfusion-angular-dropdownlist --style=scss

Navigate to the created project folder.

cd syncfusion-angular-dropdownlist

Installing Syncfusion DropDownList package

Syncfusion packages are distributed in npm as @syncfusion scoped packages. You can get all the Angular Syncfusion package from npm link.

Currently, Syncfusion provides two types of package structures for Angular components,

  1. Ivy library distribution package format
  2. Angular compatibility compiler(Angular’s legacy compilation and rendering pipeline) package.

Ivy library distribution package

Syncfusion Angular packages(>=20.2.36) has been moved to the Ivy distribution to support the Angular Ivy rendering engine and the package are compatible with Angular version 12 and above. To download the package use the below command.

Add @syncfusion/ej2-angular-dropdowns package to the application.

npm install @syncfusion/ej2-angular-dropdowns --save

Angular compatibility compiled package(ngcc)

For Angular version below 12, you can use the legacy (ngcc) package of the Syncfusion Angular components. To download the ngcc package use the below.

Add @syncfusion/ej2-angular-dropdowns@ngcc package to the application.

npm install @syncfusion/ej2-angular-dropdowns@ngcc --save

To mention the ngcc package in the package.json file, add the suffix -ngcc with the package version as below.

@syncfusion/ej2-angular-dropdowns:"20.2.38-ngcc"

Note: If the ngcc tag is not specified while installing the package, the Ivy Library Package will be installed and this package will throw a warning.

Registering DropDownList module

Import DropDownList module into Angular application(app.module.ts) from the package @syncfusion/ej2-angular-dropdowns.

import { NgModule }      from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
// import the DropDownListModule for the DropDownList component
import { DropDownListModule } from '@syncfusion/ej2-angular-dropdowns';
import { AppComponent }  from './app.component';

@NgModule({
  //declaration of ej2-angular-dropdowns module into NgModule
  imports:      [ BrowserModule, DropDownListModule ],
  declarations: [ AppComponent ],
  bootstrap:    [ AppComponent ]
})
export class AppModule { }

Adding CSS reference

The following CSS files are available in ../node_modules/@syncfusion package folder.
This can be referenced in [src/styles.css] using following code.

@import '../node_modules/@syncfusion/ej2-base/styles/material.css';
@import '../node_modules/@syncfusion/ej2-buttons/styles/material.css';
@import '../node_modules/@syncfusion/ej2-dropdowns/styles/material.css';
@import '../node_modules/@syncfusion/ej2-inputs/styles/material.css';
@import '../node_modules/@syncfusion/ej2-popups/styles/material.css';
@import '../node_modules/@syncfusion/ej2-lists/styles/material.css';
@import '../node_modules/@syncfusion/ej2-angular-dropdowns/styles/material.css';

Adding DropDownList component

Modify the template in [src/app/app.component.ts] file to render the DropDownList component. Add the Angular DropDownList by using <ejs-dropdownlist> selector in template section of the app.component.ts file.

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

@Component({
  selector: 'app-root',
  // specifies the template string for the DropDownList component
  template: `<ejs-dropdownlist id='ddlelement'></ejs-dropdownlist>`
})
export class AppComponent  { }

Binding data source

After initialization, populate the DropDownList with data using the dataSource property. Here, an array of string values passed to DropDownList component.

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

@Component({
    selector: 'app-root',
    // specifies the template string for the DropDownList component
    template: `<ejs-dropdownlist id='ddlelement' [dataSource]='data'></ejs-dropdownlist>`
})
export class AppComponent {
    constructor() {
    }
    // defined the array of data
    public data: string[] = ['Snooker', 'Tennis', 'Cricket', 'Football', 'Rugby'];
}

Running the application

After completing the configuration required to render a basic DropDownList, run the following command to display the output in your default browser.

ng serve

The following example illustrates the output in your browser.

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

@Component({
    selector: 'app-root',
    // specifies the template string for the DropDownList component with dataSource
    template: `<ejs-dropdownlist id='ddlelement' [dataSource]='data' placeholder = 'Select a game'></ejs-dropdownlist>`
})
export class AppComponent {
    constructor() {
    }
    // defined the array of data
    public data: string[] = ['Snooker', 'Tennis', 'Cricket', 'Football', 'Rugby'];
}
import { NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { FormsModule, ReactiveFormsModule } from '@angular/forms';
import { AppComponent } from './app.component';
import { DropDownListModule } from '@syncfusion/ej2-angular-dropdowns';
import { ButtonModule } from '@syncfusion/ej2-angular-buttons';
/**
 * Module
 */
@NgModule({
    imports: [
        BrowserModule,FormsModule, ReactiveFormsModule, DropDownListModule, ButtonModule
    ],
    declarations: [AppComponent],
    bootstrap: [AppComponent]
})
export class AppModule { }
import { platformBrowserDynamic } from '@angular/platform-browser-dynamic';
import { enableProdMode } from '@angular/core';
import { AppModule } from './app.module';

import 'zone.js';
enableProdMode();
platformBrowserDynamic().bootstrapModule(AppModule);

Configure the popup list

By default, the width of the popup list automatically adjusts according to the DropDownList input element’s width, and the height of the popup list has ‘300px’.

The height and width of the popup list can also be customized using the popupHeight  and popupWidth property respectively.

In the following sample, popup list’s width and height are configured.

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

@Component({
    selector: 'app-root',
    // specifies the template url path
    template: `<ejs-dropdownlist id='ddlelement' [dataSource]='data' placeholder='Select a game' popupHeight='200px' popupWidth='250px' ></ejs-dropdownlist>`
})
export class AppComponent {
    constructor() {
    }
    // defined the array of data
    public data: string[] = ['Badminton', 'Basketball', 'Cricket', 'Football', 'Golf', 'Hockey', 'Rugby', 'Snooker','Tennis'];
}
import { NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { FormsModule, ReactiveFormsModule } from '@angular/forms';
import { AppComponent } from './app.component';
import { DropDownListModule } from '@syncfusion/ej2-angular-dropdowns';
import { ButtonModule } from '@syncfusion/ej2-angular-buttons';
/**
 * Module
 */
@NgModule({
    imports: [
        BrowserModule,FormsModule, ReactiveFormsModule, DropDownListModule, ButtonModule
    ],
    declarations: [AppComponent],
    bootstrap: [AppComponent]
})
export class AppModule { }
import { platformBrowserDynamic } from '@angular/platform-browser-dynamic';
import { enableProdMode } from '@angular/core';
import { AppModule } from './app.module';

import 'zone.js';
enableProdMode();
platformBrowserDynamic().bootstrapModule(AppModule);

Two-way binding

In DropDownList, the value property supports two-way binding functionality. The following example demonstrates how to work the two-way binding functionality in DropDownList.

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

@Component({
    selector: 'app-root',
    // specifies the template string for the DropDownList component and
    // input element for checking the two-way binding support using value property
    template: `
    <ejs-dropdownlist id='ddlelement' [dataSource]='data' [(value)]='value' placeholder='Select a game'></ejs-dropdownlist>
    <div style='margin-top: 50px'>
        <input type="text" [(ngModel)]="value" style="width:245px;height:25px" />
     </div>
    `
})
export class AppComponent {
    constructor() {
    }
    // defined the array of complex data
    public data: string[] = [ 'Badminton', 'Basketball', 'Cricket', 'Football' ];
    // set a value to pre-select
    public value: string = 'Badminton';
}
import { NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { FormsModule, ReactiveFormsModule } from '@angular/forms';
import { AppComponent } from './app.component';
import { DropDownListModule } from '@syncfusion/ej2-angular-dropdowns';
import { ButtonModule } from '@syncfusion/ej2-angular-buttons';
/**
 * Module
 */
@NgModule({
    imports: [
        BrowserModule,FormsModule, ReactiveFormsModule, DropDownListModule, ButtonModule
    ],
    declarations: [AppComponent],
    bootstrap: [AppComponent]
})
export class AppModule { }
import { platformBrowserDynamic } from '@angular/platform-browser-dynamic';
import { enableProdMode } from '@angular/core';
import { AppModule } from './app.module';

import 'zone.js';
enableProdMode();
platformBrowserDynamic().bootstrapModule(AppModule);

See Also