How to put class="active" to first element in vuejs for loop

Vue小助理

77人浏览 · 2022-08-23 21:33:14

Vue小助理 · 2022-08-23 21:33:14 发布

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I'm trying to learn vue.js. I'm adding list of elements, I want to add class="active" only to the first element in the for loop. following is my code:

<div class="carousel-inner text-center " role="listbox">
    <div class="item" v-for="sliderContent in sliderContents">
        <h1>{{ sliderContent.title }}</h1>
        <p v-html="sliderContent.paragraph"></p>
    </div>
</div>

So the first element should look like something this:

<div class="item active">
    <h1>WELCOME TO CANVAS</h1>
    <p>Create just what you need for your Perfect Website. Choose from a wide<br>range of Elements & simple put them on your own Canvas</p>
</div>

I'm able to get the data so everything is working perfectly fine.

And following is my script code:

<script>
export default{
    data() {
        return {
            sliderContents: [
                {
                    title: "WELCOME TO CANVAS",
                    paragraph: "Create just what you need for your Perfect Website. Choose from a wide<br>range of Elements & simple put them on your own Canvas"
                },
                {
                    title: "WELCOME TO CANVAS",
                    paragraph: "Create just what you need for your Perfect Website. Choose from a wide<br>range of Elements & simple put them on your own Canvas"
                },
                {
                    title: "WELCOME TO CANVAS",
                    paragraph: "Create just what you need for your Perfect Website. Choose from a wide<br>range of Elements & simple put them on your own Canvas"
                },
                {
                    title: "WELCOME TO CANVAS",
                    paragraph: "Create just what you need for your Perfect Website. Choose from a wide<br>range of Elements & simple put them on your own Canvas"
                }
            ]
        }
    }
}

Help me out.

Answers

const TextComponent = {
  template: `
    <p>{{ text }}</p>
  `,
  
  props: ['text'],
};

new Vue({
  components: {
    TextComponent,
  },
  
  template: `
    <div>
      <text-component
        v-for="(item, index) in items"
        :class="{ 'active': index === 0 }"
        :text="item.text">
      </text-component>
    </div>
  `,
  
  data: {
    items: [
      { text: 'Foo' },
      { text: 'Bar' },
      { text: 'Baz' },
    ],
  },
}).$mount('#app');

.active {
  background-color: red;
}

<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width">
  <title></title>
</head>
<body>
  <div id="app"></div>
  <script src="https://cdnjs.cloudflare.com/ajax/libs/vue/2.0.3/vue.js"></script>
</body>
</html>

Above is a snippet demonstrating a solution to your problem. Here's an outline of it:

Inside v-for blocks we have full access to parent scope properties. v-for also supports an optional second argument for the index of the current item.

– https://v2.vuejs.org/v2/guide/list.html#Basic-Usage

The v-for directive has a second argument giving you the index of the item.