Vue.js on:change event

Vue has the change event which will be fired when you change the data in your html controlls

So you can add the textChangeHandler method to your control as shown below.

<input  :id="product.id" v-on:change="textChangeHandler($event)" v-model='purchaseorder.products[index]' />

1	<input :id="product.id" v-on:change="textChangeHandler($event)" v-model='purchaseorder.products[index]' />

Now you can define your handler like below

 methods:{
    textChangeHandler:function($event){
       console.log($event.target.id)
     });
  }

methods:{

textChangeHandler:function($event){

console.log($event.target.id)

});

}

Here you can simply capture the id of the control