Open the DatePicker popup upon focusing input of DatePicker in Vue DatePicker component

<template>
  <div id="app">
        <div class='wrap'>
           <ejs-datepicker ref="dateObj" id='date' placeholder="Choose a date" :focus='onFocus'></ejs-datepicker>
        </div>
  </div>
</template>
<script>
import Vue from "vue";
import { DatePickerPlugin } from "@syncfusion/ej2-vue-calendars";

Vue.use(DatePickerPlugin);
export default {
    methods:{
        onFocus: function(args){
            this.$refs.dateObj.show();
        }
    }
}
</script>
<style>
  @import '../node_modules/@syncfusion/ej2-base/styles/material.css';
  @import '../node_modules/@syncfusion/ej2-buttons/styles/material.css';
  @import '../node_modules/@syncfusion/ej2-inputs/styles/material.css';
  @import '../node_modules/@syncfusion/ej2-popups/styles/material.css';
  @import "../node_modules/@syncfusion/ej2-vue-calendars/styles/material.css";
 .wrap {
    margin: 35px auto;
    width: 240px;
}
</style>