How to add dynamically attribute in VueJs

You can bind it to a variable using v-bind:disabled="foo" or :disabled="foo" for short:

<textfield label="Name" value.sync="el.name" :disabled="myVar">

Then in Vue you can just set this.myVar = true and it will disable the input.

Edit: add this to your template:

<template>
  <input type="text" :disabled="disabled" :placeholder="placeholder" v-model="value">
</template>