How could I use const in vue template?

If you expose them on your data, you are making them unnecessary reactive, as @mix3d mentioned...

A better approach is to add them into Vue object Reactivity in Depth:

<template>      <div v-if="action === CREATE_ACTION">Something</div></template><script>export default {    created() {        this.CREATE_ACTION = CREATE_ACTION;        this.UPDATE_ACTION = UPDATE_ACTION;    }})</script>

Expose them on your data.

new Vue({    ...    data:{        CREATE_ACTION: CREATE_ACTION        UPDATE_ACTION: UPDATE_ACTION    }    ...})

You can use plugin for this purpose as you want to include this in multiple components:

// constsPlugin.jsconst YOUR_CONSTS = {  CREATE_ACTION: 1,  UPDATE_ACTION: 2  ...}let YourConsts = {}; // As suggested by the comments.YourConsts.install = function (Vue, options) {  Vue.prototype.$getConst = (key) => {    return YOUR_CONSTS[key]  }}export default YourConsts

in main.js or where you define new Vue(), you have to use it like this:

import YourConsts from 'path/to/plugin'Vue.use(YourConsts)

Now you can use this in a component template like following:

<div>   <select :disabled="mode === $getConst('UPDATE_ACTION')"></div>