Vue.js Class and Style Bindings tutorial

Vue.js Class and Style Bindings tutorial

In this tutorial, we are going to learn about how to dynamically add and remove class names, inline styles in vuejs.

Class Bindings

Vue.js offers us a v-bind:class directive to dynamically add and remove classes based on a particular condition.

In this tutorial we are using the shorthand syntax of v-bind:class is :class

Let’s see an example.

Currently, we are using the object syntax to bind the class names dynamically.

<template>
 <!-- <div :class="{className:propertyName}"> -->
 <div :class="{red:isActive}">   <h1>Hello vuejs</h1>
   <button @click="isActive=!isActive">Click me</button>
 </div>
</template>

<script>
 export default{
     data:function(){
         return{
             isActive:false         }
     }
 }
</script>

<style>
  .red{      background-color:red;  }</style>

In the above code, we added :class="{red:isActive}" to our div tag, it means we are telling the vuejs please add red class to a div tag if isActive data property is true.

Array syntax

Currently, we are adding our red class if isActive property is true, sometimes we need to add the other class name if isActive property is false in such cases we need to use Array syntax inside the quotes.

<template>
             <!-- array syntax -->
 <!-- <div :class="[propertyName?'className':'className']"> -->
 <div :class="[isActive?'red':'green']">   <h1>Hello vuejs</h1>
   <button @click="isActive=!isActive">Click me</button>
 </div>
</template>

<script>
 export default{
     data:function(){
         return{
             isActive:false
         }
     }
 }
</script>

<style>
  .red{
      background-color:red;
  }
  .green{
      background-color:green;
  }
</style>

vuejs-class-bindings

Here we adding the red class if isActive property is true otherwise we are adding the green class.

Inline style Bindings

We can also bind the inline styles in Vue by using the :style directive.

example:

<template>
  <!-- object syntax -->
  <!-- <div :style="{'css-propertyName':properyName}"> -->
  <div :style="{ 'background-color': color }">    <h1>Hello vuejs</h1>
    <button @click="color = 'red';">Change to Red color</button>    <button @click="color = 'green';">Change to Green color</button>  </div>
</template>

<script>
export default {
  data: function() {
    return {
      color: ""
    };
  }
};
</script>

Here we added a :style="{ 'background-color': color }" to our div tag so that if we click on a Change to Red color button our background color is changing to red and if we click on a Change to Green color button our background color is changing to green.