angular2 dynamic form calculate amount total

Question

Trying to calculate a total payOffs.amount (payOffs is a FormArray). Not sure how to do it properly so the total would observe changes to current and new for amounts. Here i

Answer 1

I added a function:

// calculate a sum of all payoffs
sumPayOffs() {
  return this.myModel.payOffs.reduce((sum, val) => sum + val.amount, 0);
}

and in HTML (just before "Add Pay Off" button) I added readonly number field, displaying the sum:

  


  Add Pay Off

I changed pay offs field type from text to number, so inserted into mode value will be numeric.

Updated plunker: http://plnkr.co/edit/Q5HYcpnPQosSYvk2KkoP?p=preview