Proper way to re-initialize the data in VueJs 2.0

Question

I was going through this answer on SO : Is there a proper way of resetting a component's initial data in vuejs?

However, the current method is not allowed now and VueJS prohibits changing the $data var.

As you can see here in this https://github.com/vuejs/vue/issues/2873 ( $data is not allowed to be modified. )

So if I try the above method, I am getting a VueJS warning:

[Vue warn]: Avoid replacing instance root $data. Use nested data properties instead.

Here is my JS code,

function initialState () {         return {             h2: 0,             ch4: 0,             c2h6: 0,             c2h4: 0,             c2h2: 0,             c3h8: 0,             c3h6: 0,             co: 0,             co2: 0,             o2: 0,             n2: 0,             selected: ''         }     }     export default {         name: 'something',         data () {             return initialState() // This is working fine          },         computed: {             tdcg: function () {                 // some logic here...             }         },         methods: {             resetFields: function () {                 this.$data = initialState() // --> This is what I want to achieve!             }         }     } 

So what is the correct and the easiest way of re initialising my data?

Answer 1

You can use Object.assign to iterate through all properties and assign them:

export default {     data () {         return {             h2: 0,             // other attributes...         };     },     methods: {         resetFields () {             Object.assign(this.$data, this.$options.data.call(this));         }     } } 

Here's a demo fiddle: https://jsfiddle.net/797yyvtz/

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Note: I'm using this.$options.data to call the original data method again to get a fresh copy of the data. No need for a separate initialState function. The data method is the initial state function.