如何将formArray添加到formGroup？

Question

first of all apologize for my English.

I have a problem when trying to add an array field to a formGroup.

I'm trying to add a formArray using the push method to my rate formGroup, and the error I have I think is due to the formControlName.

As I searched and read the problem it is there, but I can not solve it, can someone help me please?

I created this stackblitz so you can see the error it gives me.

https://stackblitz.com/edit/angular-mlk2mh

Answer 1

To work with FormArray you need to understand this:

                Need form group
                   \/\/\/
<form [formGroup]="rates">
    <input type="text" placeholder="credit_card" formControlName="credit_card" />
                       Need form array name
                          \/\/\/
    <div formArrayName="servicesRates" *ngFor="let item of rates.get('servicesRates').controls; let i = index;">
        <div [formGroupName]="i"> <-- this is important
            <input type="text" placeholder="id" formControlName="id" />
            <input type="text" placeholder="Servicio" formControlName="service" />
            <input type="text" placeholder="Price" formControlName="price" />
        </div>
    </div>
</form>

To work above HTML your TS must be:

rates: FormGroup;
servicesRates: FormArray;

this.rates = this._formBuilder.group({
  credit_card: [null, Validators.compose([Validators.required, Validators.minLength(8)])],
  servicesRates: this._formBuilder.array([
    this._formBuilder.group({
      id: 0,
      service: '',
      price: 0,
    })
  ])
});

and addNew function:

addField() {
   this.servicesRates = this.rates.get('servicesRates') as FormArray;
   this.servicesRates.push(this.servicesRates);
}