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Accordion Component for VueJS and GSAP

takaneichinose profile image Takane Ichinose ・3 min read

Accordion component, written in VueJS. The animations are done with GSAP.


How it works

Let's just style an accordion on however you want it. You may make it colourful, or simple.

The only difference is the caret. I did not do it like how you commonly do the triangle thing by CSS. I tried to make my own (ugly, and for modern browsers only) way.

.accordion-caret {
  background-image: linear-gradient(to top right, transparent 50%, #727272 50%);
  width: 0.5rem;
  height: 0.5rem;
  transform: rotate(-45deg);
}

I don't know, but it was more comfortable for me to style, than do the traditional way to do the triangle. Also, well, I want a little change.

  • Disclaimer: Note that I am pretty sure that there is someone who already did that way. It's just like I am not actually browsing the internet to get a code, to do all of these (except for the documentation for each libraries/frameworks which I browse the official documentation).

The Vue VM

Because I can't put a real-world data on my pen, I just put a static data to be supplied. It must be placed on the VM.

var app = new Vue({
  el: '#app',
  data: {
    // 'title' is for the header. The area that you can see.
    // 'description' is for the content. It will show after you expand an accordion menu
    // 'active' is for the flag, if the content is shown or not.
    contents: [{
      title: "'Lorem ipsum dolor sit amet',"
      description: "'Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.',"
      active: false
    }, {
      title: "'Ut enim ad minim veniam',"
      description: "'Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.',"
      active: false
    } // ...
    ]
  }
});

Template

I just looped the passed props from the VM to the component, to display the template or the design of the accordion.

<div class="accordion">
  <!-- Looping of the props. -->
  <div
    class="accordion-item"
    v-for="content, i in contents"
    v-bind:class="{ 'accordion-active': content.active }"
  >
    <div class="accordion-header">
      <!-- The click event of each accordion menu -->
      <a href="#" v-on:click="expand(event, i)">
        <div class="accordion-header-div">{{ content.title }}</div>
        <div class="accordion-header-div">
          <div class="accordion-caret"></div>
        </div>
      </a>
    </div>
    <!-- We need the ref to get the DOM of the body. -->
    <div class="accordion-body" v-bind:ref="'accordion-body-' + i">
      <div class="accordion-content">{{ content.description }}</div>
    </div>
  </div>
</div>
  • I used the HTML highlighting so that the element may be comprehended easily. Also, because there is also an other way to write our template.

Animation for the expansion

Below is how you do the expansion. Basically, I used GSAP to do akk the works in animation. Honestly, it is easier to use, than the CSS animation. Also, its transition is better than the native CSS transition.

// The dom of the accordion body, we will bind the GSAP animation here
let el = this.$refs['accordion-body-' + i][0];

if (this.contents[i].active === false) {
  this.contents[i].active = true;

  // The GSAP animation for the expansion of an accordion menu
  TweenLite.to(el, 1, {
    height: el.scrollHeight,
    ease: Elastic.easeOut.config(1, 0.3)
  });
} else {
  this.contents[i].active = false;

  // The GSAP animation to hide the accordion menu content
  TweenLite.to(el, 0.5, {
    height: 0,
    ease: Bounce.easeOut
  });
}
  • To read more about GSAP, you may follow this link: Greensock

  • VueJS documentation: VueJS Guide

  • Addition: Yes, the guide itself is really comprehensible, that when you read it, you can actually use VueJS, comfortably.


Demo

Discussion

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