How to temporize the analysis of an <input> field?

Question

I would like to analyze the content of an field when there is no user activity.

I will take below a simple example (counting the number o

Answer 1

That works the way it is supposed to. As it is said in the docs:

It will update any bindings that depend on computed property when the original data changes

But there's a way to do it:

var app = new Vue({
  el: '#root',
  data: {
    message: '',
    messageLength:  0
  },
  methods: {
    len: _.debounce(
      function() {
        this.messageLength = this.message.length
      }, 
      300 // time
    )
  }
})

<script src="https://cdnjs.cloudflare.com/ajax/libs/vue/2.1.6/vue.js"></script>
<script src="https://unpkg.com/underscore@1.8.3"></script> <!-- undescore import -->
<div id="root">
  <input v-model="message" v-on:keyup="len">Length: <span>{{ messageLength }}</span>
</div>

Full example: https://vuejs.org/v2/guide/computed.html#Watchers

p.s. A comment about computed being sync from the vue's author: https://forum-archive.vuejs.org/topic/118/throttle-computed-properties/3

p.p.s Classics article about difference between debounce and throttle.