[angular] Setting values of input fields with Angular 6

I've ran into some trouble setting the value of an input element using Angular.

I'm trying to set the value of dynamically created input elements in my application by this method:

copyPricingToAll(): void {
  var copyValue: string = document.getElementById("priceInputGlobal").value;

  this.currentItem.orderLines.forEach(orderLine => {
  document.getElementById("priceInput-" + orderLine.id).setAttribute("value", copyValue);
   });
  }

I'm creating the rows like this:

<ng-container *ngFor="let orderLine of currentItem.orderLines let i=index">
    <tr>
       <td>{{getCorrectTimeString(orderLine)}}</td>
       <td>{{orderLine.quantity}}</td>
       <td><input id="priceInput-{{orderLine.id}}" type="number" value="{{orderLine.price}}"></td>
    </tr>
</ng-container>

Unfortunately .value is not recognized as a valid operation. I'm not sure how to correctly set the value of a dynamically created element in angular. I hope someone is able to help me out with this issue.

This question is related to angular typescript

The answer is


As an alternate you can use reactive forms. Here is an example: https://stackblitz.com/edit/angular-pqb2xx

Template

<form [formGroup]="mainForm" ng-submit="submitForm()">
  Global Price: <input type="number" formControlName="globalPrice">
  <button type="button" [disabled]="mainForm.get('globalPrice').value === null" (click)="applyPriceToAll()">Apply to all</button>
  <table border formArrayName="orderLines">
  <ng-container *ngFor="let orderLine of orderLines let i=index" [formGroupName]="i">
    <tr>
       <td>{{orderLine.time | date}}</td>
       <td>{{orderLine.quantity}}</td>
       <td><input formControlName="price" type="number"></td>
    </tr>
</ng-container>
  </table>
</form>

Component

import { Component } from '@angular/core';
import { FormGroup, FormControl, FormArray } from '@angular/forms';

@Component({
  selector: 'my-app',
  templateUrl: './app.component.html',
  styleUrls: [ './app.component.css' ]
})
export class AppComponent  {
  name = 'Angular 6';
  mainForm: FormGroup;
  orderLines = [
    {price: 10, time: new Date(), quantity: 2},
    {price: 20, time: new Date(), quantity: 3},
    {price: 30, time: new Date(), quantity: 3},
    {price: 40, time: new Date(), quantity: 5}
    ]
  constructor() {
    this.mainForm = this.getForm();
  }

  getForm(): FormGroup {
    return new FormGroup({
      globalPrice: new FormControl(),
      orderLines: new FormArray(this.orderLines.map(this.getFormGroupForLine))
    })
  }

  getFormGroupForLine(orderLine: any): FormGroup {
    return new FormGroup({
      price: new FormControl(orderLine.price)
    })
  }

  applyPriceToAll() {
    const formLines = this.mainForm.get('orderLines') as FormArray;
    const globalPrice = this.mainForm.get('globalPrice').value;
    formLines.controls.forEach(control => control.get('price').setValue(globalPrice));
    // optionally recheck value and validity without emit event.
  }

  submitForm() {

  }
}

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