Update Items rows(parent,child) values at single click

Question

In dynamically added rows i have child and parentrows

I am using anjularjs and mvc 

I have stored varaiables in 2 arrays (parent and child)

coming to my problem 

here i have entered one item row like below 

https://ibb.co/P9K2JKX

right now after clicking of edit button in above screen the relevant values arre displaying on

edit popup

https://ibb.co/2k4KQ68 

In that everything is working fine

probelm is that i want to save child and parent rows at a time after clciking of parenr row update button

here without clicking of update button  in parent it was saving

 Could kindly anyone help me