I know that the title maybe a bit complex to understand (I didn't know how to put it simply), so here's a minimal example. Imagine I got a reactive object ObjectA and I try to copy one if its property:
const objectA = reactive({
name: "test"
})
const objectB_01 = reactive({
name: a.name
}) // lose reactivity
const objectB_02 = reactive({
name: ref(a.name)
}) // lose reactivity
const objectB_03 = reactive({
get name() { return a.name }
}) // keep reactivity
When I have a template that look like this:
<template>
<div>{{ objectA.name }}</div>
</template>
Then, the name is reactive (meaning, if I change it somewhere, the template gets updated instantly).
But it does not work objectB_01.name, nor objectB_02.name. It only works with objectB_03.name, but If find it a bit of a hacky solution.
My question is: is there a proper way of doing that? I mean, using a get operator does works but is really not that clean, I find...
If you want the value to be reactive across both objectA and objectB, you need a single source of the value, so getters and setters are the only way.
const objectB_03 = reactive({
get name() { return a.name },
set name(value) { a.name = value }
}) // keep reactivity
In fact, Vue2 data does just that, ref How Changes Are Tracked
When you pass a plain JavaScript object to a Vue instance as its data option, Vue will walk through all of its properties and convert them to getter/setters