I am trying to create a collapsible menu and I have adapted the following code to suit my needs (Credit https://codepen.io/AndreasFrontDev/pen/zBZZvq). The html file opens and behaves as expected when opened directly and when placed on the default website. I am trying to use it in an asp.net application from a Vendor and I find it displays the 4 main headings correctly and when I click on 1 heading, I can see the content for about a second and it immediately closes. Can anyone explain why this is happening or how to troubleshoot this. The code is as follows. I don’t know why this file behaves differently when the file is referenced from the application. Thanks for your help.
<!DOCTYPE html>
<html>
<head>
<meta name="viewport" content="width=device-width, initial-scale=1">
<style>
.accordion {
background-color: #eee;
color: #444;
cursor: pointer;
padding: 18px;
width: 100%;
border: none;
text-align: left;
outline: none;
font-size: 15px;
transition: 0.4s;
}
.active, .accordion:hover {
background-color: #ccc;
}
.accordion:After {
content: ' 02B';
color: #777;
font-weight: bold;
float: right;
margin-left: 5px;
}
.active:after {
content: "2212";
}
.panel {
padding: 0 18px;
background-color: white;
max-height: 0;
overflow: hidden;
transition: max-height 0.2s ease-out;
}
</style>
</head>
<body>
<h2>Accordion with symbols</h2>
<p>In this example we have added a "plus" sign to each button. When the user clicks on the button, the "plus" sign is replaced with a "minus" sign.</p>
<button class="accordion">Section 1</button>
<div class="panel">
<p>Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.</p>
</div>
<button class="accordion">Section 2</button>
<div class="panel">
<p>Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.</p>
</div>
<button class="accordion">Section 3</button>
<div class="panel">
<p>Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.</p>
</div>
<script>
var acc = document.getElementsByClassName("accordion");
var i;
for (i = 0; i < acc.length; i++) {
acc[i].addEventListener("click", function() {
this.classList.toggle("active");
var panel = this.nextElementSibling;
if (panel.style.maxHeight) {
panel.style.maxHeight = null;
} else {
panel.style.maxHeight = panel.scrollHeight + "px";
}
});
}
</script>
</body>
</html>