patching value inside of rows in angular 4

Question

How can i patch the value inside of my row. I have this unit_price that if i selected a specific ingredient in the select option, it would patch it in the input field of the unit_price? Pls see this link for the codes SEE THIS LINK

onSelectIngredient(event): void {
    const formData ={
      ingredient_id: event.target.value
    }
    console.log(formData);
    this.patchValues();
  }

Answer 1

Make the following Changes to the patchValue method.

 patchValues(id,i) {
    let x = (<FormArray>this.addForm.controls['rows']).at(i);
    console.log(x);

    x.patchValue({
      unit_price: this.ingredients[id - 1].price
    });
  }



  onSelectIngredient(event,i): void {
    const formData = {
      ingredient_id: event.target.value
    }
    console.log(formData,i);
    this.patchValues(event.target.value,i);
  }

Template Changes

<select (change)="onSelectIngredient($event,i)" class="form-control" formControlName="ingredient_id"> // to get the row id

Working example in link