[feature request] @Watch multiple properties.

It would be great if we could do:

  @Watch([
    'prop1',
    'prop2',
  ])
  handler() {
    // Do something
  }

[kaorun343]

@Alendorff

Hi.

vm.$watch can receive a function whereas ComponentOption.watch can’t do so.

https://vuejs.org/v2/api/#watch

@Component
class App extends Vue {
  @Watch('propA', watchOptionsIfNeeded)
  @Watch('propB', watchOptionsIfNeeded)
  watchHandler() {}
}

[runxc1]

So this is actually something that you can do already do in vue.js and it looks like there are a couple different ways to do it.

Below is the discussion on the exact feature request to Vue.js https://github.com/vuejs/vue/issues/844#issuecomment-335026928

It looks like the most document way is to use a function to watch more than one property. https://vuejs.org/v2/api/#vm-watch shows the following example

vm.$watch(
  function () {
    return this.a + this.b
  },
  function (newVal, oldVal) {
    // do something
  }
)

It would be nice to be able to do something like

@Watch(function () {
   return this.a + this.b
 }, "myHandler")
 myHandler(newVal, oldVal) {
   // Do something
 }