Develop Reference

How can I make 2 functions onclick work in JS?

I try to create a simple traffic light system for a project however once i use the onclick="maakGroen();maakRood();"> the 2nd function does not work....
This is my code
<input type="button" name="Licht" value="Licht" onclick="maakGroen();maakRood();">
<script>
var Licht = document.getElementById('Licht');
function maakRood() {
Licht.src = "stop1.png";
}
function maakGroen() {
Licht.src = "stop2.png";
}

Use setTimeout() to delay the second function so you can see the first function's change.
<input type="button" name="Licht" value="Licht" onclick="maakGroen();setTimeout(maakRood, 1000);">

Try using an event listeners, in the example below, you can replace querySelector with getElementByID; more info on the developer site or you can find tutorials on w3schools
https://developer.mozilla.org/en-US/docs/Web/API/EventTarget/addEventListener.
document.querySelector(".elementname").addEventListener("click", doStuff)
function doStuff() {
maakGroen();
maakRood();
}
If you don't like this, then you can simply make a new function with all the code from maakGroen();maakRood(); pasted into it.

You can create a third function with both functions in it and use a timeout just like #Barmar said.

Are you looking for something like that ?
(your question is really unclear!)
const trafficLights = document.querySelectorAll('.traffic-light')
trafficLights.forEach(Tl => Tl.addEventListener('click', permuteTLcolor ))
function permuteTLcolor()
{
if (this.classList.contains('red')) { this.classList.replace('red','green'); return }
if (this.classList.contains('green')) { this.classList.replace('green','yellow'); return }
if (this.classList.contains('yellow')) { this.classList.replace('yellow','red'); return }
this.classList.add('red')
}
.traffic-light {
display : inline-block;
width : 2.6em;
height : 8em;
border-radius : .7em;
background : #1c1641;
margin : 1em;
padding-top : .3em;
cursor : pointer;
}
.traffic-light:hover {
background : #372c69;
}
span {
display : block;
width : 2em;
height : 2em;
border-radius : 50%;
margin : .4em .3em;
box-sizing : border-box;
border : .2em #97b2cc42 solid;
}
.traffic-light > span:nth-of-type(1) { background: #441111; }
.traffic-light > span:nth-of-type(2) { background: #36360d; }
.traffic-light > span:nth-of-type(3) { background: #0b270b; }
.traffic-light.red > span:nth-of-type(1) { background: #fc1515; border: 0; }
.traffic-light.yellow > span:nth-of-type(2) { background: #f3f314; border: 0; }
.traffic-light.green > span:nth-of-type(3) { background: #28e728; border: 0; }
<div class="traffic-light red">
<span></span><span></span><span></span>
</div>
<div class="traffic-light green">
<span></span><span></span><span></span>
</div>
<div class="traffic-light yellow">
<span></span><span></span><span></span>
</div>
<div class="traffic-light red">
<span></span><span></span><span></span>
</div>

Page load Function (js) is not working when Web page loads

I have been trying to find out how to call my function that is inside a function that is started on page load to set darkmode.
If anyone could help me with this I would be very grateful.
Here is my js file:
(function() {
var darkSwitch = document.getElementById("darkSwitch");
if (darkSwitch) {
initTheme();
darkSwitch.addEventListener("change", function(event) {
resetTheme();
});
function initTheme() {
var darkThemeSelected =
localStorage.getItem("darkSwitch") !== null &&
localStorage.getItem("darkSwitch") === "dark";
darkSwitch.checked = darkThemeSelected;
darkThemeSelected
? document.body.setAttribute("data-theme", "dark")
: document.body.removeAttribute("data-theme");
}
function resetTheme() {
if (darkSwitch.checked) {
document.body.setAttribute("data-theme", "dark");
localStorage.setItem("darkSwitch", "dark");
} else {
document.body.removeAttribute("data-theme");
localStorage.removeItem("darkSwitch");
}
}
}
})();
The js file comes from this GitHub:
https://github.com/coliff/dark-mode-switch

I think you try when the page is load is in dark mode.
here is the solution of your problem.
Here its Documentation :
Here's a link! This code is from Codepen.
HTML:
<script>
// Include this script near the top of your html
var app = document.getElementsByTagName("BODY")[0];
if (localStorage.lightMode == "dark") {
app.setAttribute("data-light-mode", "dark");
}
</script>
<h1>
Dark Mode Toggle
</h1>
<p>Uses localStorage to store and apply the set light mode when page is loaded</p>
<button onclick="toggle_light_mode()">
Toggle Light Mode
</button>
CSS
body {
transition: background-color 0.3s;
text-align: center;
font-family: sans-serif;
padding-top: 3em;
}
h1 {
font-weight: normal;
}
button {
padding: 1em;
font-size: 1em;
background: #000;
color: #fff;
border: none;
cursor: pointer;
transition: .3s;
}
button:hover {
opacity:.5;
}
body[data-light-mode="dark"] {
background-color: #000;
color: #eee;
}
body[data-light-mode="dark"] button {
background-color: #fff;
color: #000;
}
JS
function toggle_light_mode() {
var app = document.getElementsByTagName("BODY")[0];
if (localStorage.lightMode == "dark") {
localStorage.lightMode = "light";
app.setAttribute("data-light-mode", "light");
} else {
localStorage.lightMode = "dark";
app.setAttribute("data-light-mode", "dark");
}
console.log("lightMode = " + localStorage.lightMode);
}

Collecting input data and showing it in div

I have some quantity inputs. I want to collect the data in "inputs" and show them in "#yolcudropdown". But I just can't pull the data. Inputs must be disabled. There should be no manual entry. I did something at the bottom of the "javascript" section. But I couldn't run it.
(function( $ ) {
$.fn.number = function(customOptions) {
var options = {
'containerClass' : 'number-style',
'minus' : 'number-minus',
'plus' : 'number-plus',
'containerTag' : 'div',
'btnTag' : 'span'
};
options = $.extend(true, options, customOptions);
var input = this;
input.wrap('<' + options.containerTag + ' class="' + options.containerClass + '">');
var wrapper = input.parent();
wrapper.prepend('<' + options.btnTag + ' class="' + options.minus + '"></' + options.btnTag + '>');
var minus = wrapper.find('.' + options.minus);
wrapper.append('<' + options.btnTag + ' class="' + options.plus + '"></' + options.btnTag + '>');
var plus = wrapper.find('.' + options.plus);
var min = input.attr('min');
var max = input.attr('max');
if(input.attr('step')){
var step = +input.attr('step');
} else {
var step = 1;
}
if(+input.val() <= +min){
minus.addClass('disabled');
}
if(+input.val() >= +max){
plus.addClass('disabled');
}
minus.click(function () {
var input = $(this).parent().find('input');
var value = input.val();
if(+value > +min){
input.val(+value - step);
if(+input.val() === +min){
input.prev('.' + options.minus).addClass('disabled');
}
if(input.next('.' + options.plus).hasClass('disabled')){
input.next('.' + options.plus).removeClass('disabled')
}
} else if(!min){
input.val(+value - step);
}
});
plus.click(function () {
var input = $(this).parent().find('input');
var value = input.val();
if(+value < +max){
input.val(+value + step);
if(+input.val() === +max){
input.next('.' + options.plus).addClass('disabled');
}
if(input.prev('.' + options.minus).hasClass('disabled')){
input.prev('.' + options.minus).removeClass('disabled')
}
} else if(!max){
input.val(+value + step);
}
});
};
})(jQuery);
$('.quntity-input').each(function () {
$(this).number();
});
/* THIS IS IMPORTANT */
$(document).ready(function() {
$(document).on('change', '.btw', function() {
$('#yolcudropdown').text($(this).val());
});
});
.number-style {
display: -ms-flexbox;
display: flex;
-ms-flex-wrap: wrap;
flex-wrap: wrap;
-ms-flex-pack: start !important;
justify-content: flex-start !important;
-ms-flex-align: center !important;
align-items: center !important;
}
.number-style .number-minus,
.number-style .number-plus {
height: 28px;
background: #ffffff;
border: 2px solid #e2e2e2 !important;
width: 28px;
-webkit-border-radius: 100%;
-moz-border-radius: 100%;
-ms-border-radius: 100%;
border-radius: 100%;
line-height: 23px;
font-size: 19px;
font-weight: 700;
text-align: Center;
border: none;
display: block;
cursor: pointer;
}
.number-style .number-minus:active,
.number-style .number-plus:active {
background: #e2e2e2;
}
.number-style .number-minus {
line-height: 20px;
}
.number-style .number-minus::after {
content: "-";
font-size: 10px;
}
.number-style .number-plus {
line-height: 18px;
}
.number-style .number-plus::after {
content: "+";
font-size: 10px;
}
.number-style .quntity-input {
width: 28px;
background: #e00f23;
-webkit-border-radius: 100%;
-moz-border-radius: 100%;
-ms-border-radius: 100%;
border-radius: 100%;
line-height: 21px;
font-size: 14px;
color: #ffffff;
font-weight: 700;
text-align: Center;
margin: 0 5px;
display: block;
cursor: pointer;
text-align: center;
border: none;
height: 28px;
font-weight: 600;
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<input class="quntity-input btw" type="text" value="0" step="1" min="0" max="10">
<input class="quntity-input btw" type="text" value="0" step="1" min="0" max="10">
<div id="yolcudropdown">İnput quantity show this div</div>
"class" names of "input" elements are the same. I need to collect inputs with the same value and display them in the div instantly

HTMLInputElement
Input type "text" has no min max or step attributes, so your HTML is absolutely invalid. Try not to write It-works, I'm a framework -code. Respect the W3C standards.
Use type="number" (CSS pseudos can help you remove default spinner arrows from such elements)
Also step could be floats. Respect that and use parseFloat() in JS
CSS Flex to align stuff
Seems you know about CSS-flex, use it! Height, therefore- line-height... 19? 20? 23px? No. Just use flex.
CSS !important
!important is sign of poor coding style and should be left to Bootstrap only. Or to hopefully override Bootstrap styles - or in that cases when developers actually know what they are doing.
jQuery Plugins
jQuery plugins, I suggest to read the DOCS and get a deeper knowledge on how plugins work. Almost every jQuery method is a plugin. .hide() , .addClass()... I won't count them all. Plugins are chainable .removeClass("foo").stop().fadeTo(1), and so should be your .number() plugin.
To achieve chain-ability you simply return the bound this. PS: that's not jQuery... that's how JS works.
jQuery Plugins are not meant to be called inside a $.each() loop. $() is already a collection of DOM Nodes wrapped in a jQuery Object. No need to .each(). Same like: you would rather use $('a').css({color:'blue'}) instead of $('a').each(){ $(this).css({color: 'blue'}); });. Same effect, less code. Plugins.
jQuery DOM ready
jQuery(function($) { }); // DOM ready and $ alias in scope
Or if you don't care about ±IE, or you use ES6 syntax and a toolchain like Babel than: jQuery($ => { }) will suffice.
jQuery $ Object Constructor
jQuery allows you to define an HTMLElement that will eventually become a new DOM element wrapped with all the jQuery powers, Methods. Meaning that, if instead of passing a selector, you pass a more complex Tag-alike string (say: $("<span/>", {}); - jQuery will create an inMemory SPAN element and allow you to use the second parameter {} for most of the available jQuery Methods for that $Element. Let's use this!
jQuery plugin callbacks
If you want to provide a callback after a user changes the input value, provide a callback method. Don't force a programmer to write new spaghetti code, stick to the scope of your available Plugin internal Methods.
Sum Elements values
To sum Elements values you can use Array.prototype.reduce, just make sure to use an initialValue to prevent possible TypeErrors.
Example
Finally, here's the simplified CSS and improved JS:
(function($) {
$.fn.number = function(customOptions) {
const options = $.extend(true, {
containerTag: "div",
containerClass: "number-style",
minusClass: "number-minus", // consistency in wording!
minusText: "-", // Give power to the user!
plusClass: "number-plus",
plusText: "+",
btnTag: "button",
onChange() {}, // Provide a nifty callback!
}, customOptions);
this.each(function() { // Use .each() here!
const $input = $(this);
let val = parseFloat($input.value || 0); // floats!
const min = parseFloat($input.attr("min"));
const max = parseFloat($input.attr("max"));
const step = parseFloat($input.is("[step]") ? $input.attr("step") : 1);
const handleStyles = () => {
$minus.toggleClass('disabled', val <= min);
$plus.toggleClass('disabled', val >= max);
};
const change = () => {
val = Math.max(min, Math.min(max, val)); // Keep val in range.
$input.val(val); // Update input value
handleStyles(); // Update styles
options.onChange.call($input[0], val); // Trigger a public callback
}
const decrement = () => {
val -= step;
change();
};
const increment = () => {
val += step;
change();
};
const $minus = $(`<${options.btnTag}>`, {
type: "button",
title: "Decrement",
class: options.minusClass,
text: options.minusText,
on: {
click: decrement
}
});
const $plus = $(`<${options.btnTag}>`, {
class: options.plusClass,
title: "Increment",
text: options.plusText,
on: {
click: increment
}
});
const $wrapper = $(`<${options.containerTag}>`, {
class: options.containerClass,
});
$input.after($wrapper);
$wrapper.append($minus, $input.detach(), $plus); // Append all
handleStyles(); // handle initial styles
});
return this; // make your plugin chainable!
};
})(jQuery);
jQuery(function($) { // DOM ready and $ alias in scope
const $quantityInp = $('.quantity-input'); // Cache your elements!
const $dropdown = $('#yolcudropdown'); // Cache your elements!
$quantityInp.number({
onChange(val) { // our custom onChange callback!
const tot = $quantityInp.get().reduce((acc, el) => {
acc += parseFloat(el.value);
return acc;
}, 0);
$dropdown.text(tot);
}
});
});
/* QuickReset */ * { margin:0; box-sizing:border-box; }
.number-style input::-webkit-outer-spin-button,
.number-style input::-webkit-inner-spin-button {
-webkit-appearance: none;
}
.number-style {
display: flex;
}
.number-style > * {
height: 2em;
min-width: 2em;
border-radius: 2em;
display: flex; /* Use flex. */
justify-content: center;
text-align: center;
border: 0;
background: #ddd;
}
.number-style button {
background: #fff;
box-shadow: inset 0 0 0 2px #ccc;
cursor: pointer;
user-select: none;
/* no highlight, please! */
}
.number-style button:active {
background: #0bf;
}
.number-style input {
background: #e00f23;
color: #fff;
margin: 0 5px;
}
.number-style .disabled {
opacity: 0.2;
cursor: default;
}
/* Custom overrides: */
.number-style>* {
width: 2em;
/* just for roundness */
}
<input class="quantity-input" type="number" value="0" step="1" min="0" max="10">
<input class="quantity-input" type="number" value="0" step="1" min="0" max="10">
<div id="yolcudropdown">0</div>
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.4.1/jquery.min.js"></script>
Additional reading:
HTMLInputElement
Math/min
Math/max
jQuery plugin-creation
$ new-elements
Array/reduce
jQuery.toggleClass()
And PS: it's "quantity", not "quntity"

onmouseover not working in option [duplicate]

I am trying to show a description when hovering over an option in a select list, however, I am having trouble getting the code to recognize when hovering.
Relevant code:
Select chunk of form:
<select name="optionList" id="optionList" onclick="rankFeatures(false)" size="5"></select>
<select name="ranks" id="ranks" size="5"></select>
Manipulating selects (arrays defined earlier):
function rankFeatures(create) {
var $optionList = $("#optionList");
var $ranks = $("#ranks");
if(create == true) {
for(i=0; i<5; i++){
$optionList.append(features[i]);
};
}
else {
var index = $optionList.val();
$('#optionList option:selected').remove();
$ranks.append(features[index]);
};
}
This all works. It all falls apart when I try to deal with hovering over options:
$(document).ready(
function (event) {
$('select').hover(function(e) {
var $target = $(e.target);
if($target.is('option')) {
alert('yeah!');
};
})
})
I found that code while searching through Stack Exchange, yet I am having no luck getting it to work. The alert occurs when I click on an option. If I don't move the mouse and close the alert by hitting enter, it goes away. If I close out with the mouse a second alert window pops up. Just moving the mouse around the select occasionally results in an alert box popping up.
I have tried targeting the options directly, but have had little success with that. How do I get the alert to pop up if I hover over an option?

You can use the mouseenter event.
And you do not have to use all this code to check if the element is an option.
Just use the .on() syntax to delegate to the select element.
$(document).ready(function(event) {
$('select').on('mouseenter','option',function(e) {
alert('yeah');
// this refers to the option so you can do this.value if you need..
});
});
Demo at http://jsfiddle.net/AjfE8/

try with mouseover. Its working for me. Hover also working only when the focus comes out from the optionlist(like mouseout).
function (event) {
$('select').mouseover(function(e) {
var $target = $(e.target);
if($target.is('option')) {
alert('yeah!');
};
})
})

You don't need to rap in in a function, I could never get it to work this way. When taking it out works perfect. Also used mouseover because hover is ran when leaving the target.
$('option').mouseover(function(e) {
var $target = $(e.target);
if($target.is('option')) {
console.log('yeah!');
};
})​
Fiddle to see it working. Changed it to console so you don't get spammed with alerts. http://jsfiddle.net/HMDqb/

That you want is to detect hover event on option element, not on select:
$(document).ready(
function (event) {
$('#optionList option').hover(function(e) {
console.log(e.target);
});
})​

I have the same issue, but none of the solutions are working.
$("select").on('mouseenter','option',function(e) {
$("#show-me").show();
});
$("select").on('mouseleave','option',function(e) {
$("#show-me").hide();
});
$("option").mouseover(function(e) {
var $target = $(e.target);
if($target.is('option')) {
alert('yeah!');
};
});
Here my jsfiddle https://jsfiddle.net/ajg99wsm/

I would recommend to go for a customized variant if you like to ease
capture hover events
change hover color
same behavior for "drop down" and "all items" view
plus you can have
resizeable list
individual switching between single selection and multiple selection mode
more individual css-ing
multiple lines for option items
Just have a look to the sample attached.
$(document).ready(function() {
$('.custopt').addClass('liunsel');
$(".custopt, .custcont").on("mouseover", function(e) {
if ($(this).attr("id") == "crnk") {
$("#ranks").css("display", "block")
} else {
$(this).addClass("lihover");
}
})
$(".custopt, .custcont").on("mouseout", function(e) {
if ($(this).attr("id") == "crnk") {
$("#ranks").css("display", "none")
} else {
$(this).removeClass("lihover");
}
})
$(".custopt").on("click", function(e) {
$(".custopt").removeClass("lihover");
if ($("#btsm").val() == "ssm") {
//single select mode
$(".custopt").removeClass("lisel");
$(".custopt").addClass("liunsel");
$(this).removeClass("liunsel");
$(this).addClass("lisel");
} else if ($("#btsm").val() == "msm") {
//multiple select mode
if ($(this).is(".lisel")) {
$(this).addClass("liunsel");
$(this).removeClass("lisel");
} else {
$(this).addClass("lisel");
$(this).removeClass("liunsel");
}
}
updCustHead();
});
$(".custbtn").on("click", function() {
if ($(this).val() == "ssm") {
$(this).val("msm");
$(this).text("switch to single-select mode")
} else {
$(this).val("ssm");
$(this).text("switch to multi-select mode")
$(".custopt").removeClass("lisel");
$(".custopt").addClass("liunsel");
}
updCustHead();
});
function updCustHead() {
if ($("#btsm").val() == "ssm") {
if ($(".lisel").length <= 0) {
$("#hrnk").text("current selected option");
} else {
$("#hrnk").text($(".lisel").text());
}
} else {
var numopt = +$(".lisel").length,
allopt = $(".custopt").length;
$("#hrnk").text(numopt + " of " + allopt + " selected option" + (allopt > 1 || numopt === 0 ? 's' : ''));
}
}
});
body {
text-align: center;
}
.lisel {
background-color: yellow;
}
.liunsel {
background-color: lightgray;
}
.lihover {
background-color: coral;
}
.custopt {
margin: .2em 0 .2em 0;
padding: .1em .3em .1em .3em;
text-align: left;
font-size: .7em;
border-radius: .4em;
}
.custlist,
.custhead {
width: 100%;
text-align: left;
padding: .1em;
border: LightSeaGreen solid .2em;
border-radius: .4em;
height: 4em;
overflow-y: auto;
resize: vertical;
user-select: none;
}
.custlist {
display: none;
cursor: pointer;
}
.custhead {
resize: none;
height: 2.2em;
font-size: .7em;
padding: .1em .4em .1em .4em;
margin-bottom: -.2em;
width: 95%;
}
.custcont {
width: 7em;
padding: .5em 1em .6em .5em;
/* border: blue solid .2em; */
margin: 1em auto 1em auto;
}
.custbtn {
font-size: .7em;
width: 105%;
}
h3 {
margin: 1em 0 .5em .3em;
font-weight: bold;
font-size: 1em;
}
ul {
margin: 0;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<h3>
customized selectable, hoverable resizeable dropdown with multi-line, single-selection and multiple-selection support
</h3>
<div id="crnk" class="custcont">
<div>
<button id="btsm" class="custbtn" value="ssm">switch to multi-select mode</button>
</div>
<div id="hrnk" class="custhead">
current selected option
</div>
<ul id="ranks" class="custlist">
<li class="custopt">option one</li>
<li class="custopt">option two</li>
<li class="custopt">another third long option</li>
<li class="custopt">another fourth long option</li>
</ul>
</div>

How to toggle a selected class in a global click event?

I'm creating my component library in vue, and I defined my component checkbox, the code is like this:
<template>
<div class="checkboxcont" :class="{'checkboxcont-selected': isSelected}" #click="clickevent">
<span class="j-checkbox">
<input type="checkbox" />
</span>
<slot></slot>
</div>
</template>
<script>
export default {
data() {
return {
isSelected: false
}
},
methods: {
clickevent(event) {
if(this.isSelected) {
this.isSelected = false;
} else {
this.isSelected = true;
}
}
},
}
</script>
Now, I hope that when I click the checkbox to set the data "isSelected" false, I can give the component class "checkboxcont-selected-last", and when I click other checkbox component, the classname "checkboxcont-selected-last" can be removed, how can I listen my click event to finish it? I try to use native JavaScript code to add the classname of the dom, but it seemed to have nothing when I binded the classname of my component with Vue.js:
clickevent(event) {
if(this.isSelected) {
this.isSelected = false;
this.$el.classList.add("checkboxcont-selected-last");
} else {
this.isSelected = true;
}
}
What should I do to solve this problem, please?
Here is my style code using less:
<style lang="less" scoped rel="stylesheet/less">
#import '../../mixin/mixin.less';
.checkboxcont {
display: inline-block;
&:hover {
cursor: pointer;
.j-checkbox {
border-color: #jbluelight;
}
}
}
.j-checkbox {
position: relative;
top: 0;
left: 0;
width: 12px;
height: 12px;
display: inline-block;
border: 1px solid #border;
border-radius: 3px;
line-height: 12px;
vertical-align: -3px;
margin: 0 5px;
z-index: 20;
transition: all .2s linear;
input {
opacity: 0;
position: absolute;
left: 0;
top: 0;
visibility: hidden;
/*display: none;*/
}
}
.checkboxcont-selected {
.j-checkbox {
background: #jbluelight;
border-color: #jbluelight;
&:after {
content: '';
width: 4px;
height: 7px;
border: 2px solid white;
border-top: none;
border-left: none;
position: absolute;
left: 3px;
top: 0;
z-index: 30;
transform: rotate(45deg) scale(1);
}
}
}
</style>
<style lang="less" rel="stylesheet/less">
#import '../../mixin/mixin.less';
.checkboxcont-selected-last .j-checkbox {
border-color: #jbluelight;
}
</style>
My initial thought is that I add the class by using this.$el after I clicked the component, it can be accessed because I dispatched the click event, and I just can't access the other component:
if(this.isSelected) {
this.isSelected = false;
this.$el.classList.add("checkboxcont-selected-last")
} else {
this.isSelected = true;
}
And I remove the class by using native HTML DOM operation when I dispatch the click event because I can not access the other component, so the complete definition of clickevent is that:
clickevent(event) {
let selectedLast = document.querySelector(".checkboxcont-selected-last");
if(selectedLast) {
selectedLast.classList.remove("checkboxcont-selected-last")
}
if(this.isSelected) {
this.isSelected = false;
this.$el.classList.add("checkboxcont-selected-last")
} else {
this.isSelected = true;
}
}
It looks good, but I can not add classname of my component when I use v-bind to bind my component's classname, is it wrong? And Is it unable to use native HTML DOM operation when I bind my component's classname with Vue?

A better way to dynamically add or remove class can be using v-bind:class. There are different ways you can add a dynamic class based on a vue data variable.
I see you are already using it:
<div class="checkboxcont" :class="{'checkboxcont-selected': isSelected}" #click="clickevent">
So here this div will have only one class : checkboxcont if isSelected is false, and two classes : checkboxcont and checkboxcont-selected if isSelected is true.
Edited:
Given that you want to add a class to DOM on another component, I can think of two ways:
Using Web API: You can do following if you know the id of the element you want to add class using Element.className:
var d = document.getElementById("yourElem") d.className += " otherclass"
Vuex way: You can have a centralised state provided by vue or use vuex to manage state, these state variables can be changed across components, and can be used to add/remove class dynamically.
You can have a look at my this answer to understand more about vuex.