Checkbox Checked Event in Angular Example

April 26, 2020 | Category : Angular

Hi

In this example, i will show you angular input checkbox change event. In this article, we will implement a checkbox change event angular. I’m going to show you about checkbox change event in angular 9. Here you will learn checkbox change event in angular. So, let's follow few step to create example of angular checkbox change event example.

you'll learn angular input checkbox change event. you will do the following things for checkbox change event angular.

You can call checkbox change event in angular 6, angular 7, angular 8 and angular 9 application.

So, let's follow bellow step to create simple example. you can also see bellow screen shot for checkbox in angular app.

Step 1: Import FormsModule

If you want to create form in angular app then you need to import FormsModule from @angular/forms library. so let's add following code to app.module.ts file.

src/app/app.module.ts

import { BrowserModule } from '@angular/platform-browser';

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

import { AppComponent } from './app.component';

import { FormsModule, ReactiveFormsModule } from '@angular/forms';

@NgModule({

declarations: [

AppComponent

],

imports: [

BrowserModule,

FormsModule,

ReactiveFormsModule

],

providers: [],

bootstrap: [AppComponent]

})

export class AppModule { }

Step 2: Form with ngModel

In this step, we will write code of html form with ngModel. so add following code to app.component.html file.

I used bootstrap class on this form. if you want to add than then follow this link too: Install Boorstrap 4 to Angular 9.

src/app/app.component.html

<div class="container">

<h1>Angular CheckBox Example - HDTuto.com</h1>

<form [formGroup]="form" (ngSubmit)="submit()">

<div class="form-group">

<label for="website">Website:</label>

<div *ngFor="let web of websiteList">

<label>

<input type="checkbox" [value]="web.id" (change)="onCheckboxChange($event)" />

{{web.name}}

</label>

</div>

</div>

<button class="btn btn-primary" type="submit" [disabled]="!form.valid">Submit</button>

</form>

</div>

Step 3: updated Ts File

In ts file. we will write submit() and get all input fields values. we need to import this libraries FormBuilder, FormGroup, FormControl, Validators, FormArray. so let's add following code to app.component.ts file.

src/app/app.component.ts

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

import { FormBuilder, FormGroup, FormControl, Validators, FormArray} from '@angular/forms';

@Component({

selector: 'app-root',

templateUrl: './app.component.html',

styleUrls: ['./app.component.css']

})

export class AppComponent {

form: FormGroup;

websiteList: any = [

{ id: 1, name: 'HDTuto.com' },

{ id: 2, name: 'HDTuto.com' },

{ id: 3, name: 'NiceSnippets.com' }

];

constructor(private formBuilder: FormBuilder) {

this.form = this.formBuilder.group({

website: this.formBuilder.array([], [Validators.required])

})

}

onCheckboxChange(e) {

const website: FormArray = this.form.get('website') as FormArray;

if (e.target.checked) {

website.push(new FormControl(e.target.value));

} else {

const index = website.controls.findIndex(x => x.value === e.target.value);

website.removeAt(index);

}

}

submit(){

console.log(this.form.value);

}

}

Now you can run your application using following command:

ng serve

You can check now.

I hope it can help you...