How to conditionally add attributes for an element in Vue.js

In this tutorial, we are going to learn about how to add attributes to an HTML element conditionally in Vue.js.

Normally, we add an attribute to html element in vue using the attributename = 'value'.

Example:

<button disabled="true">Sign in</button>

The above code disables the button.

Adding attributes conditionally

To add an attribute conditionally (or dynamically) to a element, we can use the v-bind directive followed by the :attribute=value in Vue.js.

Here is an example, that adds the disabled attribute conditionally to a button element based on the email field text length.

<template>
  <div id="app">
    <input placeholder="email" v-model="email" />
    <button v-bind:disabled="!email.length">Send me</button>  </div>
</template>

<script>
export default {
  name: "App",
  data() {
    return {
      email: "",    };
  },
};
</script>

This above code, adds the disabled attribute to a button element when an email field is empty and removes the disabled attribute when an email field is not empty.

v-bind directive can be also written in short hand syntax like this:

<button :disabled="!email.length">Send me</button>