在 angular 中，如何将不同的 FormGroup 动态添加到 FormArray 中？

Question

I want to dynamically add several dishes into this order array. Each dish is a FormGroup. Dish could be pizza, salad, drink or something else. Before adding anything, the form should look this:

this.fb.group({
  firstName: ['', Validators.required],
  lastName: [''],
  order: this.fb.array([])
});

After added dishes, form should be something like this:

this.fb.group({
 firstName: ['', Validators.required],
 lastName: [''],
 order: this.fb.array([
   {type:pizza, name:summerPizza, size:8},
   {type:salad, name:goodsalad, size:small},
   {type:pizza, name:nicePizza, size:11},
   {type:drink, name:beer, brand:abc},
 ])
});

User can add as many items as they want. So how to do this?

Answer 1

If I understand what you want correctly, you would likely want a method that returns a formGroup you want to add to the formArray .

Making the assumption this is within a component class context.

in .ts:

formGroup = this.fb.group({
  firstName: ['', Validators.required],
  lastName: [''],
  order: this.fb.array([])
});

createOrder(): FormGroup {
  return this.fb.group({
    type: this.fb.control(""),
    name: this.fb.control(""),
    size: this.fb.control(""),
    brand: this.fb.control(""),
  });
}

then you'd have a method that would call that createOrder and add the formGroup to the formArray

get ordersFormArray(): FormArray {
 return this.formGroup.get('orders') as FormArray;
}

addOrder() {
  this.ordersFromArray.push(this.createOrder())
}