Vue - Deep watching an array of objects and calculating the change?

Question

I have an array called people that contains objects as follows:

Before

[
  {id: 0, name: \'Bob\', age: 27},
  {id: 1, n         


        

Answer 1

Your comparison function between old value and new value is having some issue. It is better not to complicate things so much, as it will increase your debugging effort later. You should keep it simple.

The best way is to create a person-component and watch every person separately inside its own component, as shown below:

Please find below a working example for watching inside person component. If you want to handle it on parent side, you may use $emit to send an event upwards, containing the id of modified person.

Vue.component('person-component', {
    props: ["person"],
    template: `
        

            {{person.name}}
            
        
`,
    watch: {
        person: {
            handler: function(newValue) {
                console.log("Person with ID:" + newValue.id + " modified")
                console.log("New age: " + newValue.age)
            },
            deep: true
        }
    }
});

new Vue({
    el: '#app',
    data: {
        people: [
          {id: 0, name: 'Bob', age: 27},
          {id: 1, name: 'Frank', age: 32},
          {id: 2, name: 'Joe', age: 38}
        ]
    }
});

    

        
List of people: