Debounce computed properties/getters in Vue
As I mention in my comment, debouncing is an inherently asynchronous operation, and so cannot return a value. Depending on your needs, you might want to debounce on the input side. There will be no difference between the value in text
and that in textComputed
, but if you v-model="textComputed"
, the value setting will be debounced.
If you specifically want a debounced version of a variable, mrogers has given a good solution.
var x = new Vue({
el: '#app',
data: {
text: 'start'
},
computed: {
textComputed: {
get() {
return this.text;
},
set: _.debounce(function(newValue) {
this.text = newValue;
}, 500)
}
}
})
<script src="//cdnjs.cloudflare.com/ajax/libs/vue/2.3.4/vue.min.js"></script>
<script src="//cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.4/lodash.js"></script>
<div id="app">
<div>
Debounced input:
<input v-model="textComputed">
</div>
<div>
Immediate input:
<input v-model="text">
</div>
<div>computed: {{ textComputed }} </div>
<div>debounced: {{ text }} </div>
</div>
I don't have any insight as to why the debounce function doesn't work on a computed property. However, an alternative solution is to put the debounce on a function in the methods
section and call it via a watch
.
https://jsfiddle.net/vsc4npv3/
HTML:
<div id="app">
<input v-model="text">
<div>computed: {{ textComputed }} </div>
<div>debounced: {{ debouncedText }} </div>
</div>
JavaScript:
var x = new Vue({
el:'#app',
data:{
text:'',
debouncedText: ''
},
watch: {
text: function (val) {
this.debouncer();
}
},
computed:{
textComputed(){
return this.text;
}
},
methods: {
debouncer: _.debounce(function(){
this.debouncedText = this.text;
},500)
}
})