Develop Reference

Drop Down direction changes according to free space

I am just into programing and I need your help.
I have an issue with my drop down sub-menu-s. I have a simple drop down on my header, however it is located too close to window border in this case only(Depending on permissions).
So the sub-menu opens beyond window border to the right side and user doesn't see the content of it.
I want it to detect if there is enough space to open on the right side. If yes, open on right. If not open on the left. Could you please help me to solve this issue?
This is how it works when it has enough space.
Here is my html:
<ul class="main-menu-list">
<li class="header-dropdown-item">
<span class="header-dropdown-item-title">Admin</span>
<img src="../Layout/images//arrow-down.svg" alt="">
<ul class="sub-menu-list">
<li class="header-dropdown-item">
<a class="arrow-right header-dropdown-item-title">Users</a>
<ul class="sub-menu-list-right">
<li>
<a class="header-sub-menu-item">New
users</a>
</li>
<li>
<a class="header-sub-menu-item">Users
management</a>
</li>
<li>
<a class="header-sub-menu-item" >Contacts List</a>
</li>
</ul>
</li>
<li class="header-dropdown-item">
<a class="arrow-right header-dropdown-item-title">Security</a>
<ul class="sub-menu-list-right">
<li>
<a class="header-sub-menu-item" >Roles</a>
</li>
<li>
<a class="header-sub-menu-item" >Roles and
Permissions</a>
</li>
<li>
<a class="header-sub-menu-item" >Column Based
Security</a>
</li>
</ul>
</li>
<li class="header-dropdown-item">
<a class="arrow-right header-dropdown-item-title">Notifications Management</a>
<ul class="sub-menu-list-right">
<li>
<a class="header-sub-menu-item"
>Email Notifications</a>
</li>
<li>
<a class="header-sub-menu-item" >Sent Email
Notifications</a>
</li>
</ul>
</li>
<li class="header-dropdown-item">
<a class="arrow-right header-dropdown-item-title">Source Data Analysis</a>
<ul class="sub-menu-list-right">
<li>
<a class="header-sub-menu-item" >Automated
Error Logging</a>
</li>
</ul>
</li>
<li class="header-dropdown-item">
<a class="arrow-right header-dropdown-item-title">Technical Services</a>
<ul class="sub-menu-list-right">
<li>
<a class="header-sub-menu-item" >Dropdown Lists</a>
</li>
<li>
<a class="header-sub-menu-item" >Unconventional
Tags</a>
</li>
<li>
<a class="header-sub-menu-item"
>Tag Matching Duplicates</a>
</li>
<li>
<a class="header-sub-menu-item" >3 Digit Code
Register</a>
</li>
</ul>
</li>
</ul>
</li>
</ul>
Here is my CSS:
.sub-menu
background-color: header-sub-menu-background-color;
color: header-sub-menu-color;
display: flex;
justify-content: flex-end;
height: header-sub-menu-height;
padding-right: page-side-padding;
span
margin: 10px 0;
display: inline-block;
cursor: pointer;
ul
margin: 0;
list-style: none;
display: flex;
align-items: center;
justify-content: space-between;
font-family: font-default-content;
font-size: font-size-ssm;
font-weight: bold;
text-transform: uppercase;
padding: 0;
li
& + li
margin-left: 30px;
a
cursor: pointer;
ul
& > li:hover
& > a,
& > span
color: header-menu-active-color;
> .arrow-right:after
border-left-color: header-menu-active-color;
> .sub-menu-list
shown()
> .sub-menu-list-right
showImmediately()
li
.arrow-right
cursor: default;
&:after
pointer-events: none;
position: absolute;
content: "";
width: 0;
height: 0;
border-top: 3px solid transparent;
border-bottom: 3px solid transparent;
border-left: 3px solid gray-color-3;
display: inline-block;
vertical-align: middle;
right: 12px;
top: 0;
bottom: 0;
margin: auto;
a:hover, span:hover
color: header-menu-active-color;
.main-menu-list li
position: relative;
.sub-menu-list, .sub-menu-list-right
hidden()
display: inline-block;
list-style: none;
position: absolute;
background-color: black-color-1;
top: 31px;
left: -15px;
z-index: $main-menu-sub-menu-list-zindex;
-webkit-box-sizing: border-box;
box-sizing: border-box;
padding: 0;
li
position: relative;
white-space:nowrap;
margin-left: 0;
:hover > .sub-menu-list-right
shown()
a
width: 100%;
font-family: font-default-content;
font-size: 10px;
font-weight: 700;
padding: 10px 32px 10px 15px;
display: inline-block;
&:hover
color: header-menu-active-color;
p:hover
color: header-menu-active-color;
.sub-menu-list
min-width: 100%;
hideWithDelay()
a
text-decoration: none;
display: inline-block;
color: gray-color-3;
.active
color: header-menu-active-color;
.sub-menu-list-right
top: 0;
left: 100%;
&:hover
.sub-menu-list
shown()
&:hover
shown()
.sub-menu-list-right
&:hover
shown()
span
background-color: black-color-1
.main-menu-list
li:first-child:nth-last-child(2)
li:first-child:nth-last-child(3)
.sub-menu-list-right
left: auto;
right: 100%;
And Pure JS:
<script type="text/javascript">
(function () {
handleMenuItems();
// functions:
function handleMenuItems() {
var menuEl = document.querySelector(".menu"),
userLinksList = menuEl && menuEl.querySelector(".user-links"),
recentlyItemListEl = menuEl && menuEl.querySelector(".recently-visited-item"),
favoriteItemListEl = menuEl && menuEl.querySelector(".favorites-item");
if (userLinksList) {
userLinksList.addEventListener("mouseover", function (evt) {
var options = {
url: "/api/userlinks",
method: "GET",
successCallback: onloadUserLinks
};
function onloadUserLinks(result) {
if (!window.__RAPMD__) {
window.__RAPMD__ = {};
}
window.__RAPMD__.lastUserLinks = result;
createMenuList(result.RecentLinks, recentlyItemListEl, "No recently visited pages");
createMenuList(result.Favorites, favoriteItemListEl, "No favorite pages");
}
if (!window.__RAPMD__ || !window.__RAPMD__.lastUserLinks) {
ajax(options);
}
});
userLinksList.addEventListener("mouseleave", function (evt) {
if (!window.__RAPMD__) {
return;
}
window.__RAPMD__.lastUserLinks = null;
});
}
}
function createMenuList(items, menuItemEl, emptyListTitle) {
if (!menuItemEl) {
return;
}
var df = document.createDocumentFragment();
(items.length ? items : [{ Title: emptyListTitle }]).forEach(function (item) {
var li = document.createElement("li"),
a = document.createElement("a");
if (item.Url) {
a.href = item.Url;
} else {
a.classList.add("empty-link-item");
}
a.innerHTML = item.Title;
li.appendChild(a);
df.appendChild(li);
});
menuItemEl.textContent = "";
menuItemEl.appendChild(df);
}
function ajax(options) {
var url = options.url,
method = options.method,
successCallback = options.successCallback,
failureCallback = options.failureCallback,
xhr = new XMLHttpRequest();
xhr.open(method, url);
xhr.onload = function () {
if (xhr.status === 200 && successCallback) {
var response = JSON.parse(xhr.responseText);
successCallback(response);
} else if (failureCallback) {
failureCallback();
}
};
xhr.send();
}
})();
</script>

I don't think there is an easy CSS way to solve this. The only option I can think about is to align it to the left if the space is not enough. You can use the document.querySelector("#sub-menu").getBoundingClientRect() function to get the position of the element.
{
"x": 1261.5,
"y": -309,
"width": 298,
"height": 452,
"top": -309,
"right": 1559.5,
"bottom": 143,
"left": 1261.5
}
Then you can check if the sub-menu would overflow out of the page and assign a class that makes it align to the left instead of the right.
const subMenuBound = document.querySelector("#sub-menu").getBoundingClientRect();
const windowWidth = document.getElementsByTagName("body")[0].clientWidth;
const subMenuX = subMenuBound.x;
const subMenuWidth = subMenuBound.width;
if (subMenuBound.width + subMenuBound.x > windowWidth) {
// assign a class to the sub-menu to
// align to the left instead of right
} else {
// remove the class
}

How can I fix this expanding issue?

So I'm trying to create an accordion style menu where if you click a panel it opens the section. If you click it again, it closes. On top of that, it should also close any other panel that was previously opened.
I've almost got that functionality but the problem is that I have to click it twice.
To see what I mean, check out this Fiddle
You'll notice that if you open link one then try to open link 2, you'll have to press link 2 twice.
How can I make it so that you only have to press it once to close link 1 but also open link 2 ?
let dropdown = document.querySelectorAll('.dropdown-toggle');
const handleClick = (e) => {
const active = document.querySelector('.open');
if(active){
active.classList.remove('open');
} else {
e.currentTarget.nextElementSibling.classList.add('open')
}
}
dropdown.forEach(element => {
element.addEventListener('click', handleClick);
});
body {
background: #ccc;
}
.menu {
background: #fff;
margin: 0 auto;
max-width: 400px;
}
.menu ul {
padding: 0;
text-align: center;
width: 100%;
}
.menu ul li {
list-style: none;
padding: 20px 0;
border-bottom: 1px solid #ccc;
}
.menu ul li a {
text-decoration: none;
}
.menu ul li .dropdown {
display: none;
padding: 20px;
background: grey;
}
.menu ul li .dropdown.open {
display: block;
}
<div class="menu">
<ul>
<li>
link 1
<div class="dropdown">Some text</div>
</li>
<li>
link 2
<div class="dropdown">Some text</div>
</li>
<li>
link 3
<div class="dropdown">Some text</div>
</li>
<li>
link 4
<div class="dropdown">Some text</div>
</li>
<li>
link 5
<div class="dropdown">Some text</div>
</li>
</ul>
</div>

Can use js like the following.
let dropdown = document.querySelectorAll('.dropdown-toggle');
const handleClick = (e) => {
const isLastOpenTargetClicked = e.currentTarget.nextElementSibling.classList.contains('open');
if(isLastOpenTargetClicked) {
e.currentTarget.nextElementSibling.classList.remove('open');
return;
}
const active = document.querySelector('.open');
if(active){
active.classList.remove('open');
}
e.currentTarget.nextElementSibling.classList.add('open')
}
dropdown.forEach(element => {
element.addEventListener('click', handleClick);
});
body {
background: #ccc;
}
.menu {
background: #fff;
margin: 0 auto;
max-width: 400px;
}
.menu ul {
padding: 0;
text-align: center;
width: 100%;
}
.menu ul li {
list-style: none;
padding: 20px 0;
border-bottom: 1px solid #ccc;
}
.menu ul li a {
text-decoration: none;
}
.menu ul li .dropdown {
display: none;
padding: 20px;
background: grey;
}
.menu ul li .dropdown.open {
display: block;
}
<div class="menu">
<ul>
<li>
link 1
<div class="dropdown">Some text</div>
</li>
<li>
link 2
<div class="dropdown">Some text</div>
</li>
<li>
link 3
<div class="dropdown">Some text</div>
</li>
<li>
link 4
<div class="dropdown">Some text</div>
</li>
<li>
link 5
<div class="dropdown">Some text</div>
</li>
</ul>
</div>

There's no need to check whether the current element is active; On the click handler you simply want to check whether the .nextElementSibling's .classList contains the class open. If it does, remove it. If it doesn't, apply it.
This can be seen in the following:
let dropdown = document.querySelectorAll('.dropdown-toggle');
const handleClick = (e) => {
if (e.currentTarget.nextElementSibling.classList.contains('open')) {
e.currentTarget.nextElementSibling.classList.remove('open');
} else {
e.currentTarget.nextElementSibling.classList.add('open')
}
}
dropdown.forEach(element => {
element.addEventListener('click', handleClick);
});
body {
background: #ccc;
}
.menu {
background: #fff;
margin: 0 auto;
max-width: 400px;
}
.menu ul {
padding: 0;
text-align: center;
width: 100%;
}
.menu ul li {
list-style: none;
padding: 20px 0;
border-bottom: 1px solid #ccc;
}
.menu ul li a {
text-decoration: none;
}
.menu ul li .dropdown {
display: none;
padding: 20px;
background: grey;
}
.menu ul li .dropdown.open {
display: block;
}
<div class="menu">
<ul>
<li>
link 1
<div class="dropdown">Some text</div>
</li>
<li>
link 2
<div class="dropdown">Some text</div>
</li>
<li>
link 3
<div class="dropdown">Some text</div>
</li>
<li>
link 4
<div class="dropdown">Some text</div>
</li>
<li>
link 5
<div class="dropdown">Some text</div>
</li>
</ul>
</div>

Inside your click handler, loop the document.querySelectorAll('.dropdown-toggle'), remove all the open from classlist, then add open to the current target

When click on second dropdown black box should remain visible

In this dropdown nav I'm building if a dropdown is opened and you click to open a second one, the black box should remain visible. At the moment the black box disappears when you click on a second dropdown and reappears after the dropdown is completely opened.
Update
I also noticed the black box shows after a dropdown is open and it should open at the same time.
I hope this makes sense and thank you for your help!
$(document).ready(function() {
$(".click").on("click", function(e) {
var menu = $(this);
toggleDropDown(menu);
});
$(document).on('mouseup',function(e) {
var container = $("nav .top-bar-section ul");
// if the target of the click isn't the container nor a descendant of the container
if (!container.is(e.target) && container.has(e.target).length === 0) {
$('a.active').parent().find('.showup').stop(true, true).slideUp(500, function() {
$(".main-container").removeClass("black-bg");
if ($('a.active').hasClass('active')) {
$('a.active').removeClass('active');
}
});
}
});
});
function toggleDropDown(menu) {
var isActive = $('a.active').length;
$('a.active').parent().find('.showup').stop(true, true).slideUp(500, function() {
$(".main-container").removeClass("black-bg");
if (menu.hasClass('active')) {
menu.removeClass('active');
} else {
$('a.active').removeClass('active');
menu.addClass('active');
menu.parent().find('.showup').stop(true, true).slideDown(500, function() {
$(".main-container").addClass("black-bg");
});
}
});
if (!isActive) {
menu.addClass('active');
menu.parent().find('.showup').stop(true, true).slideDown(500, function() {
$(".main-container").addClass("black-bg");
});
}
}
* {
box-sizing: border-box;
}
body {
margin: 0;
}
.nav-wrapper {
width: 100%;
overflow: hidden;
background: #424242;
}
nav {
width: 1024px;
margin: auto;
overflow: hidden;
background: #424242;
}
.nav-content {
width: 100%;
z-index: 999;
background: #ccc;
}
.top-bar-section {
float: left;
}
.top-bar-section a.active {
background: #f00;
}
.showup {
display: none;
background: #ccc;
position: absolute;
width: 100%;
top: 70px;
left: 0;
z-index: 99;
padding: 30px 15px 30px 20px;
}
p {
font-size: 14px;
line-height: 1.4;
}
li.nav-item {
display: inline-block;
background: #f5f5f5;
}
li.nav-item a {
display: block;
text-decoration: none;
padding: 10px;
}
.main-container {
width: 80%;
height: 400px;
margin: auto;
}
.black-bg {
background: #000;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div class="nav-wrapper">
<nav>
<div class="top-bar-section">
<ul>
<li class="nav-item">
Nav item 1
<div class="showup">
<div class="nav-content">
<p>
Dropdown for Nav Item 1.
</p>
</div>
</div>
</li>
<li class="nav-item">
Nav item 2
<div class="showup">
<div class="nav-content">
<p>
Dropdown for Nav Item 2.
</p>
</div>
</div>
</li>
<li class="nav-item">
Nav item 3
<div class="showup">
<div class="nav-content">
<p>
Dropdown for Nav Item 3.
</p>
</div>
</div>
</li>
<li class="nav-item">
Nav item 4
<div class="showup">
<div class="nav-content">
<p>
Dropdown for Nav Item 4.
</p>
</div>
</div>
</li>
</ul>
</div>
</nav>
</div>
<div class="main-container">
</div>

If you want black-bg being added once the menu is clicked, then do not remove and add black-bg class on every click event. Simply add it once if the menu have active class and remove it when menu do not active class. If you remove and add class on every click event then black-bg will first disappear and again it will appear. To black-bg at the time drop-down is open then remove $(".main-container").addClass("black-bg"); from callback function of slideDown() because a callback function is executed after the current effect is finished.
$(document).ready(function() {
$(".click").on("click", function(e) {
var menu = $(this);
toggleDropDown(menu);
});
$(document).on('mouseup',function(e) {
var container = $("nav .top-bar-section ul");
// if the target of the click isn't the container nor a descendant of the container
if (!container.is(e.target) && container.has(e.target).length === 0) {
$('a.active').parent().find('.showup').stop(true, true).slideUp(500, function() {
$(".main-container").removeClass("black-bg");
if ($('a.active').hasClass('active')) {
$('a.active').removeClass('active');
}
});
}
});
});
function toggleDropDown(menu) {
var isActive = $('a.active').length;
$('a.active').parent().find('.showup').stop(true, true).slideUp(500, function() {
if (menu.hasClass('active')) {
menu.removeClass('active');
$(".main-container").removeClass("black-bg");
} else {
$('a.active').removeClass('active');
menu.addClass('active');
menu.parent().find('.showup').stop(true, true).slideDown(500, function() {
});
}
});
if (!isActive) {
menu.addClass('active');
menu.parent().find('.showup').stop(true, true).slideDown(500);
$(".main-container").addClass("black-bg");
}
}
* {
box-sizing: border-box;
}
body {
margin: 0;
}
.nav-wrapper {
width: 100%;
overflow: hidden;
background: #424242;
}
nav {
width: 1024px;
margin: auto;
overflow: hidden;
background: #424242;
}
.nav-content {
width: 100%;
z-index: 999;
background: #ccc;
}
.top-bar-section {
float: left;
}
.top-bar-section a.active {
background: #f00;
}
.showup {
display: none;
background: #ccc;
position: absolute;
width: 100%;
top: 70px;
left: 0;
z-index: 99;
padding: 30px 15px 30px 20px;
}
p {
font-size: 14px;
line-height: 1.4;
}
li.nav-item {
display: inline-block;
background: #f5f5f5;
}
li.nav-item a {
display: block;
text-decoration: none;
padding: 10px;
}
.main-container {
width: 80%;
height: 400px;
margin: auto;
}
.black-bg {
background: #000;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div class="nav-wrapper">
<nav>
<div class="top-bar-section">
<ul>
<li class="nav-item">
Nav item 1
<div class="showup">
<div class="nav-content">
<p>
Dropdown for Nav Item 1.
</p>
</div>
</div>
</li>
<li class="nav-item">
Nav item 2
<div class="showup">
<div class="nav-content">
<p>
Dropdown for Nav Item 2.
</p>
</div>
</div>
</li>
<li class="nav-item">
Nav item 3
<div class="showup">
<div class="nav-content">
<p>
Dropdown for Nav Item 3.
</p>
</div>
</div>
</li>
<li class="nav-item">
Nav item 4
<div class="showup">
<div class="nav-content">
<p>
Dropdown for Nav Item 4.
</p>
</div>
</div>
</li>
</ul>
</div>
</nav>
</div>
<div class="main-container">
</div>

Just move $(".main-container").removeClass("black-bg"); into if (menu.hasClass('active')) {
$(document).ready(function() {
$(".click").on("click", function(e) {
var menu = $(this);
toggleDropDown(menu);
});
$(document).on('mouseup',function(e) {
var container = $("nav .top-bar-section ul");
// if the target of the click isn't the container nor a descendant of the container
if (!container.is(e.target) && container.has(e.target).length === 0) {
$('a.active').parent().find('.showup').stop(true, true).slideUp(500, function() {
$(".main-container").removeClass("black-bg");
if ($('a.active').hasClass('active')) {
$('a.active').removeClass('active');
}
});
}
});
});
function toggleDropDown(menu) {
var isActive = $('a.active').length;
$('a.active').parent().find('.showup').stop(true, true).slideUp(500, function() {
//$(".main-container").removeClass("black-bg"); FROM HERE
if (menu.hasClass('active')) {
menu.removeClass('active');
$(".main-container").removeClass("black-bg"); // TO HERE
} else {
$('a.active').removeClass('active');
menu.addClass('active');
menu.parent().find('.showup').stop(true, true).slideDown(500, function() {
$(".main-container").addClass("black-bg");
});
}
});
if (!isActive) {
menu.addClass('active');
menu.parent().find('.showup').stop(true, true).slideDown(500, function() {
$(".main-container").addClass("black-bg");
});
}
}
* {
box-sizing: border-box;
}
body {
margin: 0;
}
.nav-wrapper {
width: 100%;
overflow: hidden;
background: #424242;
}
nav {
width: 1024px;
margin: auto;
overflow: hidden;
background: #424242;
}
.nav-content {
width: 100%;
z-index: 999;
background: #ccc;
}
.top-bar-section {
float: left;
}
.top-bar-section a.active {
background: #f00;
}
.showup {
display: none;
background: #ccc;
position: absolute;
width: 100%;
top: 70px;
left: 0;
z-index: 99;
padding: 30px 15px 30px 20px;
}
p {
font-size: 14px;
line-height: 1.4;
}
li.nav-item {
display: inline-block;
background: #f5f5f5;
}
li.nav-item a {
display: block;
text-decoration: none;
padding: 10px;
}
.main-container {
width: 80%;
height: 400px;
margin: auto;
}
.black-bg {
background: #000;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div class="nav-wrapper">
<nav>
<div class="top-bar-section">
<ul>
<li class="nav-item">
Nav item 1
<div class="showup">
<div class="nav-content">
<p>
Dropdown for Nav Item 1.
</p>
</div>
</div>
</li>
<li class="nav-item">
Nav item 2
<div class="showup">
<div class="nav-content">
<p>
Dropdown for Nav Item 2.
</p>
</div>
</div>
</li>
<li class="nav-item">
Nav item 3
<div class="showup">
<div class="nav-content">
<p>
Dropdown for Nav Item 3.
</p>
</div>
</div>
</li>
<li class="nav-item">
Nav item 4
<div class="showup">
<div class="nav-content">
<p>
Dropdown for Nav Item 4.
</p>
</div>
</div>
</li>
</ul>
</div>
</nav>
</div>
<div class="main-container">
</div>

Is this what you are looking for?
$(document).ready(function() {
$(".click").on("click", function(e) {
var menu = $(this);
toggleDropDown(menu);
});
$(document).on('mouseup',function(e) {
var container = $("nav .top-bar-section ul");
// if the target of the click isn't the container nor a descendant of the container
if (!container.is(e.target) && container.has(e.target).length === 0) {
$('a.active').parent().find('.showup').stop(true, true).slideUp(500, function() {
$(".main-container").removeClass("black-bg");
if ($('a.active').hasClass('active')) {
$('a.active').removeClass('active');
}
});
}
});
});
function toggleDropDown(menu) {
var isActive = $('a.active').length;
$('a.active').parent().find('.showup').stop(true, true).slideUp(500, function() {
if (menu.hasClass('active')) {
menu.removeClass('active');
} else {
$('a.active').removeClass('active');
menu.addClass('active');
menu.parent().find('.showup').stop(true, true).slideDown(500, function() {
$(".main-container").addClass("black-bg");
});
}
});
if (!isActive) {
menu.addClass('active');
menu.parent().find('.showup').stop(true, true).slideDown(500, function() {
$(".main-container").addClass("black-bg");
});
}
The black box will remain there in this case. What you were previously doing was that you were removing black-box explicitly.

dynamic fields class change per list element and Js to recognize part of the class

class in the list element change per box and are dynamic fields with width and length being the difference between the two. How to run my JS so that only the first part of the class is recognized without the number so js variable selectors should be '.attribute__swatch--width-' and '.attribute__swatch--length-'. please see my code below:
var numbers = document.querySelectorAll(".attribute__swatch--width-"),
letters = document.querySelectorAll(".attribute__swatch--length-"),
ua = navigator.userAgent,
event = (ua.match(/iPad/i)) ? "touchstart" : "click";
numbers.forEach(function(box, index) {
$(box).on(event, function() {
letters.forEach(function(box) {
box.classList.remove("showBorder");
});
var info = document.getElementsByClassName('box-tip')[0];
if (index > 2) {
info.style.left = 11 + ((index - 3) * 45) + 'px';
} else {
info.style.left = 0 + 'px';
}
info.style.visibility = 'visible';
letters[index].classList.add("showBorder");
});
$(document).on("click", '.clicked', function() {
$('.clicked').removeClass('selected');
$(this).addClass('selected');
});
});
.list-box li {display: inline-block;list-style-type: none;padding: 1em;background:red;}
.list-box {margin:15px auto;padding:0;}
.box-sleeve li {display: inline-block;list-style-type: none;padding: 1em;background:red;}
.box-sleeve {margin:15px auto;padding:0;}
.showBorder { outline: 1px dashed #233354; outline-offset:1px;}
.box-tip {
display:inline;
margin: auto;
position: relative;
visibility: hidden;
padding-left:10px;
}
.numberCircle {
border-radius: 90%;
font-size: 12px;
border: 2px solid #000;
color: #fff;
background: #000;
padding: 0 4px;
}
.numberCircle span {
text-align: center;
display: block;
}
li.selected {color:#fff;background-color:#000;}
#media (max-width: 768px) {
.box-tip span {
position: fixed;
left: 10px;
}
.box-tip span.numberCircle {
position: fixed;
left: 236px;
}
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<span>Test some logic one width</span>
<ul class="list-box">
<li class="attribute__swatch--width-14.5">1</li>
<li class="attribute__swatch--width-15">2</li>
<li class="attribute__swatch--width-15.5">3</li>
<li class="attribute__swatch--width-16">4</li>
<li class="attribute__swatch--width-16.5">5</li>
<li class="attribute__swatch--width-17">6</li>
<li class="attribute__swatch--width-17.5">7</li>
<li class="attribute__swatch--width-18">8</li>
</ul>
<div>
<span>Test some logic two length</span>
</div>
<div class="box-tip">
<span>Regular length for your collar size</span>
<span class="numberCircle">?</span>
</div>
<ul class="box-sleeve">
<li class="attribute__swatch--length-32">a</li>
<li class="attribute__swatch--length-34">b</li>
<li class="attribute__swatch--length-36">c</li>
<li class="attribute__swatch--length-38">d</li>
<li class="attribute__swatch--length-40">e</li>
<li class="attribute__swatch--length-42">f</li>
<li class="attribute__swatch--length-44">g</li>
<li class="attribute__swatch--length-46">h</li>
</ul>

You can use attribute selectors, specifically starts with (^=) to match:
document.querySelectorAll('[class^="attribute__swatch--width-"]');
document.querySelectorAll('[class^="attribute__swatch--length-"]')

Multiselect dropdown in Asp.Net

I have a requirement to design the dropdown with multiselect option with checkbox using ASP.NET controls and also i need to select checkboxes while binding the values on the dropdown. Please help

you can use following open source library to get your goal its simple and really amazing
http://wenzhixin.net.cn/p/multiple-select/

Please check this, I developed this similar dropdown for my project.
//Multiple Dropdown Select
$('.multiDrop').on('click', function (e) {
e.stopPropagation();
$(this).next('ul').slideToggle();
});
$(document).on('click', function (){
if (!$(event.target).closest('.wrapMulDrop').length) {
$('.wrapMulDrop ul').slideUp();
}
});
$('.wrapMulDrop ul li input[type="checkbox"]').on('change', function () {
var x = $('.wrapMulDrop ul li input[type="checkbox"]:checked').length;
if (x != "") {
$('.multiDrop').html(x + " " + "selected");
} else if (x < 1) {
$('.multiDrop').html('Select Templates<i style="float:right;" class="icon ion-android-arrow-dropdown"></i>');
}
});
.wrapMulDrop {
width: 50%;
display: inline-block;
position: relative;
}
.multiDrop {
width: 100%;
padding: 5%;
background-color: transparent;
border: 1px solid #ccc;
color: #999;
text-align: left;
}
.multiDrop:focus {
outline: none;
}
.wrapMulDrop ul {
position: absolute;
margin: 0;
padding: 0;
left: 0;
right: 0;
z-index: 5;
display: none;
}
.wrapMulDrop ul li {
list-style-type: none;
background-color: #e5801d;
padding: 1% 6%;
}
.wrapMulDrop ul li:hover {
background-color: #33414e;
}
.wrapMulDrop ul li label {
width: 100% !important;
cursor: pointer;
margin: 0 !important;
color: #f1f1f1;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div class="wrapMulDrop">
<button type="button" class="multiDrop">Select Templates<i style="float:right;" class="icon ion-android-arrow-dropdown"></i>
</button>
<ul>
<li>
<input type="checkbox" id="list1">
<label for="list1">Template 1</label>
</li>
<li>
<input type="checkbox" id="list2">
<label for="list2">Template 2</label>
</li>
<li>
<input type="checkbox" id="list3">
<label for="list3">Template 3</label>
</li>
<li>
<input type="checkbox" id="list4">
<label for="list4">Template 4</label>
</li>
</ul>
</div>