Invoking a method in a child component from the parent component using Angular

Question

Invoking a method in a child component from the parent component using Angular

In my parent component, there are three instances of a child component nested inside.

child-product-detail.component.html

<form id="frmProduct" #frmProduct="ngForm" (ngSubmit)="onSave(frmProduct)">
   <ng-content select="[buttons-view]"></ng-content>
   <input type="text" id="txtProductName" name="txtProductName" [(ngModel)]="product.productName" />
</form>

child-product-detail.component.ts

onSave(form) {
    let isValid = this.validate(form);
    if (!isValid) return;
}

parent-product.compoment.html

<child-product-detail [product]="products[0]">
   <div buttons-view>
       <button type="button" class="btn" (click)="saveProduct(0)" >Save</button>                                    
   </div>
</child-product-detail>
<child-product-detail [product]="products[1]">
   <div buttons-view>
       <button type="button" class="btn" (click)="saveProduct(1)" >Save</button>                                    
   </div>
</child-product-detail>
<child-product-detail [product]="products[2]">
   <div buttons-view>
       <button type="button" class="btn" (click)="saveProduct(2)" >Save</button>                                    
   </div>
</child-product-detail>

parent-product.component.ts

saveProduct(productId) {
    let productToSave = this.products(productIndex);
    // Code needed to trigger the onSave method in the child component
}

Is it possible to invoke the onSave method of the child component and pass its form object as a parameter?

Thank you.

angular typescript

Answer 1

Answer №1

To access multiple child components, you can utilize the ViewChildren decorator in Angular.

@ViewChildren(ChildProductDetailComponent)
childComponents: QueryList<ChildProductDetailComponent>;

saveProduct(productId) {
   this.childComponents.get(productIndex).onSave();
}

Answer 2

To access multiple child components, you can utilize the ViewChildren decorator in Angular.

@ViewChildren(ChildProductDetailComponent)
childComponents: QueryList<ChildProductDetailComponent>;

saveProduct(productId) {
   this.childComponents.get(productIndex).onSave();
}

Answer 3

Answer №2

Utilize an EventEmitter for communication.

Assuming that the child component has an output event function set up like this:

<app-item-selection (outputItemEvent)="outputItemEvent($event)"></app-item-selection>

This would be the corresponding function in the parent component:

public outputItemEvent(event){
    this.item = event
  }

and in the child component:

constructor(private fb: FormBuilder) {
        this.itemForm = this.fb.group({
          x: '',
          y: '',
          z:'',
        });
       }

.....
 

    ngOnInit(): void {
        this.itemForm.valueChanges.subscribe(data =>{
          this.outputItemEvent.emit(data)
        })
      }

If you have a "Submit" button in the ParentComponent, you can gather the values and store them in a final object:

public submit(){
  let finalItem ={ "item":this.item"}
}

Answer 4

Utilize an EventEmitter for communication.

Assuming that the child component has an output event function set up like this:

<app-item-selection (outputItemEvent)="outputItemEvent($event)"></app-item-selection>

This would be the corresponding function in the parent component:

public outputItemEvent(event){
    this.item = event
  }

and in the child component:

constructor(private fb: FormBuilder) {
        this.itemForm = this.fb.group({
          x: '',
          y: '',
          z:'',
        });
       }

.....
 

    ngOnInit(): void {
        this.itemForm.valueChanges.subscribe(data =>{
          this.outputItemEvent.emit(data)
        })
      }

If you have a "Submit" button in the ParentComponent, you can gather the values and store them in a final object:

public submit(){
  let finalItem ={ "item":this.item"}
}

Answer 5

Answer №3

A great way to accomplish this is by utilizing the @Output directive to trigger custom events.

Here's an example of how you can implement it:

child-product-detail.component.ts

import { Component, EventEmitter, Output } from '@angular/core';

export class ChildProductDetailComponent {
    @Output() customEventEmitter = new EventEmitter<any>();

    onSave(form) {
        let isValid = this.validate(form);
        if (isValid) {
            this.customEventEmitter.emit(form)
        };
    }

When the onSave() function is called, it will emit the customEventEmitter.

parent-product.compoment.html

<child-product-detail (customEventEmitter)="saveProduct($event)">
    <button type="button" class="btn" (click)="onSave(0)" >Save</button>
</child-product-detail>

The parent component will then receive the event and execute the saveProduct() function, passing the form through the $event parameter.

parent-product.component.ts

saveProduct(productId) {
    // The productId here refers to the form data received from the child component
}

If you're interested in learning more about this concept, check out the documentation here.

Answer 6

A great way to accomplish this is by utilizing the @Output directive to trigger custom events.

Here's an example of how you can implement it:

child-product-detail.component.ts

import { Component, EventEmitter, Output } from '@angular/core';

export class ChildProductDetailComponent {
    @Output() customEventEmitter = new EventEmitter<any>();

    onSave(form) {
        let isValid = this.validate(form);
        if (isValid) {
            this.customEventEmitter.emit(form)
        };
    }

When the onSave() function is called, it will emit the customEventEmitter.

parent-product.compoment.html

<child-product-detail (customEventEmitter)="saveProduct($event)">
    <button type="button" class="btn" (click)="onSave(0)" >Save</button>
</child-product-detail>

The parent component will then receive the event and execute the saveProduct() function, passing the form through the $event parameter.

parent-product.component.ts

saveProduct(productId) {
    // The productId here refers to the form data received from the child component
}

If you're interested in learning more about this concept, check out the documentation here.

Invoking a method in a child component from the parent component using Angular

Answer №1

Answer №2

Answer №3

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