(Angular 5) Error: Cannot read property 'setValue' of undefined

I'm initializing my form this way, but when I need to edit it, it does not accept the values

component.ts

ngOnInit() {
this.tinvoiceService.initForm();
}


tinvoice.service.ts

form: FormGroup;

constructor(
private _fb: FormBuilder,
private invoiceService: InvoiceService
) {}

initForm(): void {
this.form = this._fb.group({
customer: [null, Validators.required],
totalPrice: 0,
purchases: this._fb.array([])
});

// initialize stream
const myFormValueChanges$ = this.form.controls['purchases'].valueChanges;
myFormValueChanges$.subscribe(purchases => this.updatePurchasesAmount(purchases));

}


from the HTML I pass the values

tinvoice.component.html

<a
class="btn btn-outline-info text-info"
(click)="tinvoiceService.populateForm(invoice)">
Edit
</a>


tinvoice-list.component.ts

populateForm(invoice) {
this.form.setValue(invoice);
}


by console I have this result



View in StackBlitz

any ideas?

Continue reading...