What is the process for an Angular 12 child component to pass an input value to its parent component?

Question

What is the process for an Angular 12 child component to pass an input value to its parent component?

child.html

<p>
  <mat-form-field appearance="outline">
    <mat-label>Password</mat-label>
    <input matInput required [type]="show ? 'password' : 'text'" class="input">
    <button mat-icon-button matSuffix (click)="show = !show" [attr.aria-label]="'Hide password'"
            [attr.aria-pressed]="show">
      <mat-icon matSuffix>{{show ? 'visibility_off' : 'visibility'}}</mat-icon>
    </button>
  </mat-form-field>
</p>

parent.html

  <password></password>

Is there a way to retrieve the value of the component password without utilizing [(ngModel)]?

angular typescript angular-material

Answer 1

Answer №1

If you want to share data from a parent component to a child component, you can make use of event emitter.

Here is an example:

In the parent component's HTML file:

onGetValue(password: string) {
    console.log('password::' + password);
}

In the child component's HTML file:

@Output() getValue: EventEmitter<string> = new EventEmitter();
onKeyupPassword(value: string) {
    this.getValue.emit(value);
}

Answer 2

If you want to share data from a parent component to a child component, you can make use of event emitter.

Here is an example:

In the parent component's HTML file:

onGetValue(password: string) {
    console.log('password::' + password);
}

In the child component's HTML file:

@Output() getValue: EventEmitter<string> = new EventEmitter();
onKeyupPassword(value: string) {
    this.getValue.emit(value);
}

Answer 3

Answer №2

RETRIEVING VALUE FROM CHILD:

local reference in HTML:

<input #childPassword matInput required [type]="show ? 'password' : 'text'" class="input">

accessing the value of the local reference in TS:

@ViewChild(‘childPassword’) childPassword!:ElementRef<HTMLInputElement>
...
const onChildPasswordValue = this.childPassword.nativeElement.value;

PASSING VALUE FROM CHILD TO PARENT:

import { ..., EventEmitter, ..., Output } from '@angular/core'; 
....
  @Output() onNewChildPassword: EventEmitter<string> 
  = new EventEmitter();
....
    this.onNewChildPassword.emit(onChildPasswordValue);

RECEIVING VALUE IN PARENT COMPONENT:

parent.html

<password (onChildPasswordValue)="parentMethodGetPassword($event)"></password>

parent.ts

public parentMethodGetPassword(password: string) {

// the child's password will be available in the 'password' parameter

}

Answer 4

RETRIEVING VALUE FROM CHILD:

local reference in HTML:

<input #childPassword matInput required [type]="show ? 'password' : 'text'" class="input">

accessing the value of the local reference in TS:

@ViewChild(‘childPassword’) childPassword!:ElementRef<HTMLInputElement>
...
const onChildPasswordValue = this.childPassword.nativeElement.value;

PASSING VALUE FROM CHILD TO PARENT:

import { ..., EventEmitter, ..., Output } from '@angular/core'; 
....
  @Output() onNewChildPassword: EventEmitter<string> 
  = new EventEmitter();
....
    this.onNewChildPassword.emit(onChildPasswordValue);

RECEIVING VALUE IN PARENT COMPONENT:

parent.html

<password (onChildPasswordValue)="parentMethodGetPassword($event)"></password>

parent.ts

public parentMethodGetPassword(password: string) {

// the child's password will be available in the 'password' parameter

}

Answer 5

Answer №3

If you're looking for a solution, consider the following approach:

To start off, in the typescript file of the Parent component, create a method that can receive the value of the password variable like so:

export class ParentComponent {

password:string;

constructor() { } 

receiveStringValue($event) {
  this.password= $event;
 }
}

Next, in the html file of the Parent component, include the following code:

<app-child (stringValueEvent)="receiveStringValue($event)"></app-child>
<h1>{{password}}<h1>

Then, in the html file of the Child component, add the following code:

<input type="password" (keyup)="onKeyupPassword(value)"/>

Lastly, in the typescript file of the Child component (under the app-child selector), define a stringValueEvent variable using the @Output() decorator and initialize it with a new event emitter.

export class ChildComponent {

  password:string;

  @Output() stringValueEvent = new EventEmitter<string>();

  constructor() { }

  onKeyupPassword(value: string) {
    this.password = value;
    this.stringValueEvent.emit(this.password)
  }

  ngOnInit(): void {
    
  }
}

Answer 6

If you're looking for a solution, consider the following approach:

To start off, in the typescript file of the Parent component, create a method that can receive the value of the password variable like so:

export class ParentComponent {

password:string;

constructor() { } 

receiveStringValue($event) {
  this.password= $event;
 }
}

Next, in the html file of the Parent component, include the following code:

<app-child (stringValueEvent)="receiveStringValue($event)"></app-child>
<h1>{{password}}<h1>

Then, in the html file of the Child component, add the following code:

<input type="password" (keyup)="onKeyupPassword(value)"/>

Lastly, in the typescript file of the Child component (under the app-child selector), define a stringValueEvent variable using the @Output() decorator and initialize it with a new event emitter.

export class ChildComponent {

  password:string;

  @Output() stringValueEvent = new EventEmitter<string>();

  constructor() { }

  onKeyupPassword(value: string) {
    this.password = value;
    this.stringValueEvent.emit(this.password)
  }

  ngOnInit(): void {
    
  }
}

Answer 7

Answer №4

solved

profile.html
<p>
  <mat-form-field appearance="outline">
    <mat-label>Profile Name</mat-label>
    <input matInput required type="text" class="input"
           [(ngModel)]="name" (keyup)="updateName(name)">
    <button mat-icon-button matSuffix disabled>
      <mat-icon matSuffix>account_circle</mat-icon>
    </button>
  </mat-form-field>
</p>

profile.component.ts
import { Component, EventEmitter, OnInit, Output } from '@angular/core';
import { FormControl, Validators } from '@angular/forms';

@Component({
  selector: 'profile',
  templateUrl: './profile.component.html',
  styleUrls: ['./profile.component.scss']
})
export class ProfileComponent implements OnInit {

  constructor() {
  }

  ngOnInit(): void {
  }

  name: string = '';

  @Output() profileName: EventEmitter<string> = new EventEmitter();

  updateName(name: string) {
    this.profileName.emit(name);
  }
}

account.html
<app-header></app-header>
<form>
  <profile (profileName)="updateProfile($event)"></profile>
  <email (email)="updateEmail($event)"></email>
  <p class="button signin">
    <button mat-raised-button color="primary" type="button"
            (click)="onSubmit()" (keyup.enter)="onSubmit()">Save Changes
    </button>
  </p>
</form>
<app-footer></app-footer>

account.component.ts
import { Component, OnInit } from '@angular/core';
import { AccountService } from './account.service';
import { Account } from './account';

@Component({
  selector: 'app-account',
  templateUrl: './account.component.html',
  styleUrls: ['./account.component.scss']
})
export class AccountComponent implements OnInit {

  constructor(
    private service: AccountService
  ) {
  }

  ngOnInit(): void {
  }

  account: Account = {
    profileName: '',
    email: ''
  };

  updateProfile(name: string) {
    this.account.profileName = name;
  }

  updateEmail(email: string) {
    this.account.email = email;
  }

  onSubmit() {
    return this.service.update(this.account);
  }

}

Answer 8

solved

profile.html
<p>
  <mat-form-field appearance="outline">
    <mat-label>Profile Name</mat-label>
    <input matInput required type="text" class="input"
           [(ngModel)]="name" (keyup)="updateName(name)">
    <button mat-icon-button matSuffix disabled>
      <mat-icon matSuffix>account_circle</mat-icon>
    </button>
  </mat-form-field>
</p>

profile.component.ts
import { Component, EventEmitter, OnInit, Output } from '@angular/core';
import { FormControl, Validators } from '@angular/forms';

@Component({
  selector: 'profile',
  templateUrl: './profile.component.html',
  styleUrls: ['./profile.component.scss']
})
export class ProfileComponent implements OnInit {

  constructor() {
  }

  ngOnInit(): void {
  }

  name: string = '';

  @Output() profileName: EventEmitter<string> = new EventEmitter();

  updateName(name: string) {
    this.profileName.emit(name);
  }
}

account.html
<app-header></app-header>
<form>
  <profile (profileName)="updateProfile($event)"></profile>
  <email (email)="updateEmail($event)"></email>
  <p class="button signin">
    <button mat-raised-button color="primary" type="button"
            (click)="onSubmit()" (keyup.enter)="onSubmit()">Save Changes
    </button>
  </p>
</form>
<app-footer></app-footer>

account.component.ts
import { Component, OnInit } from '@angular/core';
import { AccountService } from './account.service';
import { Account } from './account';

@Component({
  selector: 'app-account',
  templateUrl: './account.component.html',
  styleUrls: ['./account.component.scss']
})
export class AccountComponent implements OnInit {

  constructor(
    private service: AccountService
  ) {
  }

  ngOnInit(): void {
  }

  account: Account = {
    profileName: '',
    email: ''
  };

  updateProfile(name: string) {
    this.account.profileName = name;
  }

  updateEmail(email: string) {
    this.account.email = email;
  }

  onSubmit() {
    return this.service.update(this.account);
  }

}

What is the process for an Angular 12 child component to pass an input value to its parent component?

Answer №1

Answer №2

Answer №3

Answer №4

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