如何在加号和减号之间切换手风琴？

Question

Codepen link.

I have 6 parent accordion links, all with children. To the left, they contain font awesome plus signs.

I want to, on click, toggle the plus sign into a minus sign.

Currently I have my plusSign variable grabbing just the first plus sign to show that it works (using const plusSign = document.querySelector('.fa-plus'); ).

Works great for the first link. However, I want this to affect all instances.

I tried using querySelectorAll ( const plusSign = document.querySelectorAll('.fa-plus'); ), but it just doesn't work at all.

Code is at the link above but here's the code below just in case:

HTML:

  <!--Quick Link Box-->
  <section class="quick-link-box">
    <div class="columns is-desktop">
      <div class="column">
        <div class="card quick-link-card quick-link-card-mobile" tabindex="0">
          <ul>
            <li>
              <a class="parent accordion" tabindex="0"><i class="fa fa-plus" aria-hidden="true"></i> Control &amp; Automation</a>
              <div class="panel">
                <ul class="child">
                  <li><a href="#">Molded Machine Tool Industrial Control Transformer</a></li>
                  <li><a href="#">Industrial Open Core & Coil Control Transformer</a></li>
                  <li><a href="#">General Purpose Enclosed Transformer</a></li>
                  <li><a href="#">Encapsulated Control Transformer</a></li>
                  <li><a href="#">Energy Efficient Drive Isolation Transformer (Gen. 3)</a></li>
                  <li><a href="#">Energy Efficient Drive Isolation Transformer (Gen. 2)</a></li>
                  <li><a href="#">Drive Isolation Transformer (Gen. 1)</a></li>
                  <li><a href="#">Reactors</a></li>
                  <li><a href="#">DV/DT Filter</a></li>
                  <li><a href="#">Motor Starting Autotransformers</a></li>
                </ul>
              </div>
            </li>
            <li>
              <a class="parent accordion" tabindex="0"><i class="fa fa-plus" aria-hidden="true"></i> Medium Voltage Distribution</a>
              <div class="panel">
                <ul class="child">
                  <li><a href="#">Link #1</a></li>
                  <li><a href="#">Link #2</a></li>
                  <li><a href="#">Link #3</a></li>
                </ul>
              </div>
            </li>
            <li>
              <a class="parent accordion" tabindex="0"><i class="fa fa-plus" aria-hidden="true"></i> Low Voltage Distribution</a>
              <div class="panel">
                <ul class="child">
                  <li><a href="#">Link #1</a></li>
                  <li><a href="#">Link #2</a></li>
                  <li><a href="#">Link #3</a></li>
                </ul>
              </div>
            </li>
            <li>
              <a class="parent accordion" tabindex="0"><i class="fa fa-plus" aria-hidden="true"></i> Encapsulated &amp; Specialty</a>
              <div class="panel">
                <ul class="child">
                  <li><a href="#">Link #1</a></li>
                  <li><a href="#">Link #2</a></li>
                  <li><a href="#">Link #3</a></li>
                </ul>
              </div>
            </li>
            <li>
              <a class="parent accordion" tabindex="0"><i class="fa fa-plus" aria-hidden="true"></i> Custom Products</a>
              <div class="panel">
                <ul class="child">
                  <li><a href="#">Link #1</a></li>
                  <li><a href="#">Link #2</a></li>
                  <li><a href="#">Link #3</a></li>
                </ul>
              </div>
            </li>
            <li>
              <a class="parent accordion" tabindex="0"><i class="fa fa-plus" aria-hidden="true"></i> OEM Products</a>
              <div class="panel">
                <ul class="child">
                  <li><a href="#">Link #1</a></li>
                  <li><a href="#">Link #2</a></li>
                  <li><a href="#">Link #3</a></li>
                </ul>
              </div>
            </li>
          </ul>
        </div>
      </div>
    </div>
  </section>

JS:

const plusSign = document.querySelector('.fa-plus');

let acc = document.getElementsByClassName("accordion");
let i;

for (i = 0; i < acc.length; i++) {
  acc[i].addEventListener("click", function() {

  /* Toggle between hiding and showing the active panel */
  let panel = this.nextElementSibling;
  if (panel.style.display === "block") {
    panel.style.display = "none";
    plusSign.classList.remove('fa-minus');
    plusSign.classList.add('fa-plus');
  } else {
    panel.style.display = "block";
    plusSign.classList.remove('fa-plus');
    plusSign.classList.add('fa-minus');
  }
});
}

Answer 1

You need to make use of event object that is passed to the callback function of event listener.

event.target will give you the a tag that was clicked on, event.target.firstElementChild will give you the icon next to the a tag that was clicked on.

 let acc = document.getElementsByClassName("accordion"); let i; for (i = 0; i < acc.length; i++) { acc[i].addEventListener("click", function(e) { /* Toggle between hiding and showing the active panel */ let panel = this.nextElementSibling; if (panel.style.display === "block") { panel.style.display = "none"; e.target.firstElementChild.classList.remove('fa-minus'); e.target.firstElementChild.classList.add('fa-plus'); } else { panel.style.display = "block"; e.target.firstElementChild.classList.remove('fa-plus'); e.target.firstElementChild.classList.add('fa-minus'); } }); }

 .panel { display: none; }

 <!DOCTYPE html> <html lang="en"> <head> <meta charset="utf-8" /> <meta http-equiv="X-UA-Compatible" content="IE=edge" /> <meta name="viewport" content="width=device-width, initial-scale=1" /> <title>Product Page</title> <link rel="stylesheet" href="../css/main.css" /> <link rel="stylesheet" type="text/css" href="/fonts/MyFontsWebfontsKit.css" /> <!--AOS Animate--> <link rel="stylesheet" href="https://unpkg.com/aos@next/dist/aos.css" /> <!--Font Awesome--> <link href="https://stackpath.bootstrapcdn.com/font-awesome/4.7.0/css/font-awesome.min.css" rel="stylesheet" integrity="sha384-wvfXpqpZZVQGK6TAh5PVlGOfQNHSoD2xbE+QkPxCAFlNEevoEH3Sl0sibVcOQVnN" crossorigin="anonymous"> </head> <body> <section class="inner-content"> <!--Quick Link Box--> <section class="quick-link-box"> <div class="columns is-desktop"> <div class="column"> <div class="card quick-link-card quick-link-card-mobile" tabindex="0"> <ul> <li> <a class="parent accordion" tabindex="0"><i class="fa fa-plus" aria-hidden="true"></i> Control &amp; Automation</a> <div class="panel"> <ul class="child"> <li><a href="#">Molded Machine Tool Industrial Control Transformer</a></li> <li><a href="#">Industrial Open Core & Coil Control Transformer</a></li> <li><a href="#">General Purpose Enclosed Transformer</a></li> <li><a href="#">Encapsulated Control Transformer</a></li> <li><a href="#">Energy Efficient Drive Isolation Transformer (Gen. 3)</a></li> <li><a href="#">Energy Efficient Drive Isolation Transformer (Gen. 2)</a></li> <li><a href="#">Drive Isolation Transformer (Gen. 1)</a></li> <li><a href="#">Reactors</a></li> <li><a href="#">DV/DT Filter</a></li> <li><a href="#">Motor Starting Autotransformers</a></li> </ul> </div> </li> <li> <a class="parent accordion" tabindex="0"><i class="fa fa-plus" aria-hidden="true"></i> Medium Voltage Distribution</a> <div class="panel"> <ul class="child"> <li><a href="#">Link #1</a></li> <li><a href="#">Link #2</a></li> <li><a href="#">Link #3</a></li> </ul> </div> </li> <li> <a class="parent accordion" tabindex="0"><i class="fa fa-plus" aria-hidden="true"></i> Low Voltage Distribution</a> <div class="panel"> <ul class="child"> <li><a href="#">Link #1</a></li> <li><a href="#">Link #2</a></li> <li><a href="#">Link #3</a></li> </ul> </div> </li> <li> <a class="parent accordion" tabindex="0"><i class="fa fa-plus" aria-hidden="true"></i> Encapsulated &amp; Specialty</a> <div class="panel"> <ul class="child"> <li><a href="#">Link #1</a></li> <li><a href="#">Link #2</a></li> <li><a href="#">Link #3</a></li> </ul> </div> </li> <li> <a class="parent accordion" tabindex="0"><i class="fa fa-plus" aria-hidden="true"></i> Custom Products</a> <div class="panel"> <ul class="child"> <li><a href="#">Link #1</a></li> <li><a href="#">Link #2</a></li> <li><a href="#">Link #3</a></li> </ul> </div> </li> <li> <a class="parent accordion" tabindex="0"><i class="fa fa-plus" aria-hidden="true"></i> OEM Products</a> <div class="panel"> <ul class="child"> <li><a href="#">Link #1</a></li> <li><a href="#">Link #2</a></li> <li><a href="#">Link #3</a></li> </ul> </div> </li> </ul> </div> </div> </div> </section> </section> <!--#inner-content--> <!--JS--> <script type="text/javascript" src="../lib/main.js"></script> <script src="https://unpkg.com/aos@next/dist/aos.js"></script> <script> AOS.init(); </script> </body> </html>

Answer 2

Check this. Edited your code a bit.

 const plusSign = document.querySelector('.fa-plus'); let acc = document.getElementsByClassName("accordion"); let i; let toggleAccordion = function() { /* Toggle between hiding and showing the active panel */ let panel = this.nextElementSibling; if (panel.classList.contains("collapsed")) { alert("open acc"); panel.classList.remove("collapsed") plusSign.classList.remove('fa-plus'); plusSign.classList.add('fa-minus'); } else { alert("close acc"); panel.classList.add("collapsed") plusSign.classList.remove('fa-minus'); plusSign.classList.add('fa-plus'); } } for (i = 0; i < acc.length; i++) { acc[i].addEventListener("click",toggleAccordion); }

 .panel { display: block; } .panel.collapsed { display: none; }

 <!--Quick Link Box--> <section class="quick-link-box"> <div class="columns is-desktop"> <div class="column"> <div class="card quick-link-card quick-link-card-mobile" tabindex="0"> <ul> <li> <span class="parent accordion" tabindex="0"><i class="fa fa-plus" aria-hidden="true"></i> Control &amp; Automation</span> <div class="panel collapsed"> <ul class="child"> <li><a href="#">Molded Machine Tool Industrial Control Transformer</a></li> <li><a href="#">Industrial Open Core & Coil Control Transformer</a></li> <li><a href="#">General Purpose Enclosed Transformer</a></li> <li><a href="#">Encapsulated Control Transformer</a></li> <li><a href="#">Energy Efficient Drive Isolation Transformer (Gen. 3)</a></li> <li><a href="#">Energy Efficient Drive Isolation Transformer (Gen. 2)</a></li> <li><a href="#">Drive Isolation Transformer (Gen. 1)</a></li> <li><a href="#">Reactors</a></li> <li><a href="#">DV/DT Filter</a></li> <li><a href="#">Motor Starting Autotransformers</a></li> </ul> </div> </li> <li> <span class="parent accordion" tabindex="0"><i class="fa fa-plus" aria-hidden="true"></i> Medium Voltage Distribution</span> <div class="panel collapsed"> <ul class="child"> <li><a href="#">Link #1</a></li> <li><a href="#">Link #2</a></li> <li><a href="#">Link #3</a></li> </ul> </div> </li> <li> <span class="parent accordion" tabindex="0"><i class="fa fa-plus" aria-hidden="true"></i> Low Voltage Distribution</span> <div class="panel collapsed"> <ul class="child"> <li><a href="#">Link #1</a></li> <li><a href="#">Link #2</a></li> <li><a href="#">Link #3</a></li> </ul> </div> </li> <li> <span class="parent accordion" tabindex="0"><i class="fa fa-plus" aria-hidden="true"></i> Encapsulated &amp; Specialty</span> <div class="panel collapsed"> <ul class="child"> <li><a href="#">Link #1</a></li> <li><a href="#">Link #2</a></li> <li><a href="#">Link #3</a></li> </ul> </div> </li> <li> <span class="parent accordion" tabindex="0"><i class="fa fa-plus" aria-hidden="true"></i> Custom Products</span> <div class="panel collapsed"> <ul class="child"> <li><a href="#">Link #1</a></li> <li><a href="#">Link #2</a></li> <li><a href="#">Link #3</a></li> </ul> </div> </li> <li> <span class="parent accordion" tabindex="0"><i class="fa fa-plus" aria-hidden="true"></i> OEM Products</span> <div class="panel collapsed"> <ul class="child"> <li><a href="#">Link #1</a></li> <li><a href="#">Link #2</a></li> <li><a href="#">Link #3</a></li> </ul> </div> </li> </ul> </div> </div> </div> </section>