Data binding in Angular List box component

27 Sep 202311 minutes to read

The ListBox loads the data either from local data sources or remote data services using the dataSource property. It supports the data type of array or DataManager.

Fields	Type	Description
text	string	Specifies the display text of each list item.
value	string	Specifies the hidden data value mapped to each list item that should contain a unique value.
groupBy	string	Specifies the category under which the list item has to be grouped.
iconCss	string	Specifies the iconCss class that needs to be mapped.
htmlAttributes	string	Allows additional attributes to configure the elements in various ways to meet the criteria.

When binding complex data to the ListBox, fields should be mapped correctly. Otherwise, the selected item remains undefined.

Local Data

Local data can be represented by the following ways as described below.

Array of string

The ListBox has support to load array of primitive data such as strings or numbers. Here, both value and text field acts as same.

app.component.ts

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

@Component({
    selector: 'app-container',
    template: `<div class="e-section-control">
                <ejs-listbox [dataSource]="data"></ejs-listbox></div>`
})

export class AppComponent {
public data: string[] = ['Badminton', 'Cricket', 'Football', 'Golf', 'Tennis', 'Basket Ball', 'Base Ball', 'Hockey', 'Volley Ball'];
}

app.module.ts

import { NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { FormsModule, ReactiveFormsModule } from '@angular/forms';
import { AppComponent } from './app.component';
import { ListBoxComponent,ListBoxAllModule } from '@syncfusion/ej2-angular-dropdowns';
import { ButtonComponent } from '@syncfusion/ej2-angular-buttons';
/**
 * Module
 */
@NgModule({
    imports: [
        BrowserModule,FormsModule, ReactiveFormsModule, ListBoxAllModule
    ],
    declarations: [AppComponent],
    bootstrap: [AppComponent]
})
export class AppModule { }

main.ts

import { platformBrowserDynamic } from '@angular/platform-browser-dynamic';
import { enableProdMode } from '@angular/core';
import { AppModule } from './app.module';

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

Array of object

The ListBox can generate its list items through an array of object data. For this,
the appropriate columns should be mapped to the fields property.

In the following example, id and sports column from complex data have been mapped to the value field and text field, respectively.

app.component.ts

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

@Component({
    selector: 'app-container',
    template: `<div class="e-section-control">
               <ejs-listbox [dataSource]="data" [fields]="setfield"></ejs-listbox></div>`
})

export class AppComponent {
public data: { [key: string]: Object }[] = [
    { id: 'game1', sports: 'Badminton' },
    { id: 'game2', sports: 'Cricket'},
    { id: 'game3', sports: 'Football'},
    { id: 'game4', sports: 'Golf'},
    { id: 'game5', sports: 'Tennis'},
    { id: 'game6', sports: 'Basket Ball'},
    { id: 'game7', sports: 'Base Ball'},
    { id: 'game8', sports: 'Hockey'},
    { id: 'game9', sports: 'Volley Ball'}
];

public setfield = {
    text: "sports",
    value: "id"
 }
}

app.module.ts

import { NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { FormsModule, ReactiveFormsModule } from '@angular/forms';
import { AppComponent } from './app.component';
import { ListBoxComponent ,ListBoxAllModule} from '@syncfusion/ej2-angular-dropdowns';
import { ButtonComponent } from '@syncfusion/ej2-angular-buttons';
/**
 * Module
 */
@NgModule({
    imports: [
        BrowserModule,FormsModule, ReactiveFormsModule, ListBoxAllModule
    ],
    declarations: [AppComponent],
    bootstrap: [AppComponent]
})
export class AppModule { }

main.ts

import { platformBrowserDynamic } from '@angular/platform-browser-dynamic';
import { enableProdMode } from '@angular/core';
import { AppModule } from './app.module';

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

Array of complex object

The ListBox can generate its list items through an array of complex data. For this,
the appropriate columns should be mapped to the fields property.

In the following example, Sports.Name column from complex data have been mapped to the text field.

app.component.ts

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

@Component({
    selector: 'app-container',
    template: `<div class="e-section-control">
                <ejs-listbox [dataSource]="data" [fields]="setfield"></ejs-listbox></div>`
})

export class AppComponent {
public data: { [key: string]: Object }[] = [
    { Id: 'game1', Sports: { Name: 'Badminton'} },
    { Id: 'game2', Sports: { Name: 'Cricket'} },
    { Id: 'game3', Sports: { Name: 'Football'} },
    { Id: 'game4', Sports: { Name: 'Golf'} },
    { Id: 'game5', Sports: { Name: 'Tennis'} },
    { Id: 'game6', Sports: { Name: 'Basket Ball'} },
    { Id: 'game7', Sports: { Name: 'Base Ball'} },
    { Id: 'game8', Sports: { Name: 'Hockey'} },
    { Id: 'game9', Sports: { Name: 'Volley Ball'} }
];

public setfield = { text: "Sports.Name" }
}

app.module.ts

import { NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { FormsModule, ReactiveFormsModule } from '@angular/forms';
import { AppComponent } from './app.component';
import { ListBoxComponent, ListBoxAllModule } from '@syncfusion/ej2-angular-dropdowns';
import { ButtonComponent } from '@syncfusion/ej2-angular-buttons';
/**
 * Module
 */
@NgModule({
    imports: [
        BrowserModule,FormsModule, ReactiveFormsModule, ListBoxAllModule
    ],
    declarations: [AppComponent],
    bootstrap: [AppComponent]
})
export class AppModule { }

main.ts

import { platformBrowserDynamic } from '@angular/platform-browser-dynamic';
import { enableProdMode } from '@angular/core';
import { AppModule } from './app.module';

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

Remote Data

The ListBox supports retrieval of data from remote data services with the help of DataManager component. The Query property is used to fetch data from the database and bind it to the ListBox.

The following sample displays the first 10 products from Products table of the Northwind Data Service.

app.component.ts

import { Component } from '@angular/core';
import { DataManager,ODataV4Adaptor,Query } from '@syncfusion/ej2-data';

@Component({
    selector: 'app-container',
    template: `<div class="e-section-control">
                <ejs-listbox [dataSource]="data" [fields]="setfield" [query]="query"></ejs-listbox></div>`
})

export class AppComponent {
    public data:DataManager = new DataManager({
          url: 'https://services.odata.org/V4/Northwind/Northwind.svc/',
           adaptor: new ODataV4Adaptor,
    })
    public query = new Query().from('Products').select('ProductID,ProductName').take(10);

    public setfield = { text: "ProductName" }
}

app.module.ts

import { NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { FormsModule, ReactiveFormsModule } from '@angular/forms';
import { AppComponent } from './app.component';
import { ListBoxComponent, ListBoxAllModule } from '@syncfusion/ej2-angular-dropdowns';
import { ButtonComponent } from '@syncfusion/ej2-angular-buttons';
/**
 * Module
 */
@NgModule({
    imports: [
        BrowserModule,FormsModule, ReactiveFormsModule, ListBoxAllModule
    ],
    declarations: [AppComponent],
    bootstrap: [AppComponent]
})
export class AppModule { }

main.ts

import { platformBrowserDynamic } from '@angular/platform-browser-dynamic';
import { enableProdMode } from '@angular/core';
import { AppModule } from './app.module';

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