Develop Reference

How do I wrap adjacent elements of the same class using Javascript (no jQuery)

Everywhere I looked, it seemed that this problem has only been solved using jQuery, which I'm trying to remove completely from my project.
Here's the HTML:
<div class="codeblock"></div>
<div class="codeblock"></div>
<div class="codeblock"></div>
<p></p>
<div class="codeblock"></div>
<div class="codeblock"></div>
<p></p>
<div class="codeblock"></div>
desired result:
<div class="contentBox">
<div class="codeblock"></div>
<div class="codeblock"></div>
<div class="codeblock"></div>
</div>
<p></p>
<div class="contentBox">
<div class="codeblock"></div>
<div class="codeblock"></div>
</div>
<p></p>
<div class="contentBox">
<div class="codeblock"></div>
</div>
And here's how this can be done using jQuery, thanks to the many answers I've found on the topic
const e = '.codeblock';
$(e).not(e + '+' + e).each(function () {
$(this).nextUntil(':not(' + e + ')').addBack().wrapAll('<div class="contentBox" />');
});
Is there a way to replicate this same functionality using vanilla Javascript? I've tried using Element.nextElementSibling and checking if the class matches, but this approach wasn't very elegant and resulted in much more code than the jQuery solution.

Shortest version I could come up with:
let firstDivs = document.querySelectorAll('.codeblock:first-child, :not(.codeblock) + .codeblock');
firstDivs.forEach(function(div) {
let wrapper = document.createElement("div");
wrapper.className = 'wrapper';
div.parentNode.insertBefore(wrapper, div);
while(div.nextElementSibling && div.nextElementSibling.className == 'codeblock') {
wrapper.appendChild(div.nextElementSibling);
}
wrapper.insertBefore(div, wrapper.firstChild);
});
First, select the first .codeblock element out of each "group" - by selecting the element with that class that is the first child of its parent, and all those that do not have a .codeblock element before them.
For each of those elements, insert a new wrapper div before that element, then loop through the following element siblings, as long as they have that same class - and append those to the wrapper. And then afterwards, insert the first item to the beginning of the group. (If we did it before, the following elements would stop being siblings at this point.)

You could do something like this:
// Find all elements that match the class
document.querySelectorAll(`.${e}`).forEach(
// For each elemnt
elem => {
// If it's not the first of the group, skip it
if (elem.previousElementSibling!==null && elem.previousElementSibling.classList.contains(e)){
return;
}
// Find all adjacent elements with the same class
let o = [elem];
while (o[o.length - 1].nextElementSibling.classList.contains(e)) {
o.push(o[o.length - 1].nextElementSibling);
}
// Create a new wrapper element and give it a proper class
let wrapper = document.createElement('div');
wrapper.classList.add('contentBox');
// Insert the new wrapper immediatly before the group
elem.insertAdjacentElement('beforebegin', wrapper);
// Move the contents of the group to inside the wrapper element
wrapper.replaceChildren(...o);
}
)

It's a bit more code, but you can loop through all div and p, check every element and when matched append it to a new or existing div.codeBlock.
const isTargeted = el => el.classList.contains(`codeblock`);
const createWrap = (beforeEl) => beforeEl.insertAdjacentElement(`beforebegin`,
Object.assign(document.createElement(`div`), {className: `contentBox`}));
const divsAndPs = document.querySelectorAll(`div, p`);
divsAndPs.forEach(
(elem, i, self) => {
if (!i || isTargeted(elem)) {
const wrap = i && self[i-1].closest(`.contentBox`) ||
createWrap(elem);
wrap.appendChild(elem);
}
}
);
.contentBox {
color: green;
}
.contentBox .codeblock {
margin-left: 2rem;
}
.contentBox:before {
content: 'I am the great contentBox, here are my codeblocks:';
color: grey;
}
<div class="codeblock">x</div>
<div class="codeblock">x</div>
<div class="codeblock">x</div>
<p>paragraph</p>
<div class="codeblock">x</div>
<div class="codeblock">x</div>
<p>paragraph</p>
<div class="codeblock">x</div>
This can be a helper function (see also this stackblitz project):
const wrapIt = () => wrapAll(
document.querySelectorAll(`.codeblock, .codeblock + :not(.codeblock)`),
`codeblock`,
Object.assign(document.createElement(`div`), {className: `contentBox`}) );
setTimeout( wrapIt, 1000 );
function wrapAll(elems2Wrap, groupByClass, wrapperElement) {
const wrap = elem =>
elem.classList?.contains(groupByClass) && (elem
.previousElementSibling?.closest(`.${wrapperElement.className}`) ||
elem.insertAdjacentElement(`beforebegin`, wrapperElement.cloneNode())
).appendChild(elem);
elems2Wrap.forEach(wrap);
}
.contentBox {
color: green;
}
.contentBox .codeblock {
margin-left: 2rem;
}
.contentBox:before {
content: 'Wrapped!';
color: grey;
}
<div class="codeblock otherClass">x</div>
<div class="codeblock">x</div>
<div class="codeblock">x</div>
<p>Just a paragraph</p>
<div class="codeblock">x</div>
<div class="codeblock otherClass">x</div>
<p>Just a paragraph</p>
<div class="codeblock">x</div>

Add margin to the first element if another fourth element is lower than X pixels inside an object. Multiple objects on page

I have an object (div) which has four elements (with classes) inside.
Task: When height of the element A is lower than 40px then add to element B 20px margin-top.
However there are many objects on the page.
<div class="list">
<div class="block">
<div class="list-name" style="height: 20px">element A</div>
<div class="div1">another div here</div>
<div class="div2">another div here</div>
<div class="product-image-container">element B</div>
</div>
<div class="block">
<div class="list-name" style="height: 50px">element A</div>
<div class="div1">another div here</div>
<div class="div2">another div here</div>
<div class="product-image-container">element B</div>
</div>
(...)
</div>
Sorry, I tried this so far. However it works only if there are only two elements in the div.
$(document).ready(function(){
$('.list-name').each(function(index, obj){
console.log($(obj).height())
if($(obj).height() < 40)
{
$(obj).next('.product-image-container').css('margin-top', 20)
}
});
});
Thanks for any help.
Rob

As far as I understand, you need something like this:
var heightA = $(".list-name").css("height"); //get height of element. E.g. "20px"
heightA = heightA.substr(0, heightA.length - 2); //remove "px" from string => "20"
if (heightA < 40) { //if the height is less than 40
$(".product-image-container").css("margin-top", "20px"); //add margin-top 20px
}
To do this for all elements, you will need a for. Maybe try this:
var elements = $("body div").length; //get amount of divs. In the HTML you provided 'body' is the parent
for (i = 0; i < elements; i++) { //loop 'em all
var heightA = $("div:nth-child(" + i + ") .list-name").css("height"); //again get height of corresponding element
heightA = heightA.substr(0, heightA.length - 2); //remove "px"
if (heightA < 40) {
$("div:nth-child(" + i + ") .product-image-container").css("margin-top", "20px"); //set margin-top of corresponding element
}
}

Javascript only addEventListener to parent style both parent and child differently

Currently have a div that controls the width of an element as well as the background color. That div has a child div which has the content which is semi-transparent. Which is why I need the first div. So the background is solid.
Now, I added an event listener to the parent which expands the width of one and decreases the width of the other 2 so they all fit. However, when I click on the parent div I would like the child of that specific div to add a class and remove a class from the other 2. Which I can't seem to figure out. Here's the code. Sorry if my formatting is poor, first time posting on stack overflow and I've googled and searched everything for an answer and can't seem to find one.
var purchaseStepCont = document.querySelectorAll(".step-container");
var purchaseStep = document.querySelectorAll(".step");
for (var i = 0; i < purchaseStepCont.length; i++) {
purchaseStepCont[i].addEventListener("click", function() {
for (var i = 0; i < purchaseStepCont.length; i++) {
purchaseStepCont[i].classList.remove("stepContActive");
purchaseStepCont[i].classList.add("stepContDeactive");
this.classList.add("stepContActive");
this.classList.remove("stepContDeactive");
}
});
}
<div class="step-container">
<div class="step">
<h1>01.</h1>
<h3>words</h3>
<p>wods</p>
</div>
</div>
<div class="step-container">
<div class="step">
<h1>01.</h1>
<h3>words</h3>
<p>wods</p>
</div>
</div>
<div class="step-container">
<div class="step">
<h1>01.</h1>
<h3>words</h3>
<p>wods</p>
</div>
</div>

You're very close. But if you want to add the class to the .step, you need this.firstElementChild.classList.add(...) rather than this.classList.add(...) (since this will be the .step-container, not the .step; but the .step is its first element child). Or for more markup flexibility, you could use this.querySelector(".step").
You can also use just a single event handler function rather than recreating it in the loop:
var purchaseStepCont = document.querySelectorAll(".step-container");
var purchaseStep = document.querySelectorAll(".step");
function clickHandler() {
var thisStep = this.firstElementChild; // Or this.querySelector(".step") would be more flexible
for (var i = 0; i < purchaseStep.length; i++) {
if (purchaseStep[i] === thisStep) {
purchaseStep[i].classList.add("stepContActive");
purchaseStep[i].classList.remove("stepContDeactive");
} else {
purchaseStep[i].classList.remove("stepContActive");
purchaseStep[i].classList.add("stepContDeactive");
}
}
}
for (var i = 0; i < purchaseStepCont.length; i++) {
purchaseStepCont[i].addEventListener("click", clickHandler);
}
.stepContActive {
color: blue;
}
.stepContDeactive {
color: #ddd;
}
<div class="step-container">
<div class="step">
<h1>01.</h1>
<h3>words</h3>
<p>wods</p>
</div>
</div>
<div class="step-container">
<div class="step">
<h1>01.</h1>
<h3>words</h3>
<p>wods</p>
</div>
</div>
<div class="step-container">
<div class="step">
<h1>01.</h1>
<h3>words</h3>
<p>wods</p>
</div>
</div>
clickHandler could be a bit shorter if you don't need to support IE11:
function clickHandler() {
var thisStep = this.firstElementChild; // Or this.querySelector(".step") would be more flexible
for (var i = 0; i < purchaseStep.length; i++) {
purchaseStep[i].classList.toggle("stepContActive", purchaseStep[i] === thisStep);
purchaseStep[i].classList.toggle("stepContDeactive", purchaseStep[i] !== thisStep);
}
}
But IE11 doesn't support the second argument to classList.toggle.

How to change order of elements in html using javascript

I am creating a simple game that has 9 divisions and each 8 of the divisions have a penguin hidden in them and the 9th one has a monster. Now my game works fine but what I want to do is every time I load the page, arrangement of the divisions should change so as to add randomness to the game.
Here is my code:
$(document).ready(function() {
//This code will run after your page loads
$('body').on('mousedown', '.yeti', function(event) {
alert("Yaaaarrrr!");
});
});
<div class="gameholder">
<div class="title"></div>
<div class="penguin1"></div>
<div class="penguin2"></div>
<div class="penguin3"></div>
<div class="penguin4"></div>
<div class="penguin5"></div>
<div class="penguin6"></div>
<div class="penguin7"></div>
<div class="penguin8"></div>
<div class="yeti"></div>
</div>
After adding images and some positioning to the div's this is how it looks

Keeping Your Animals Contained
Consider creating a container for all of your game elements as you only want to randomize their order as you don't want to get the title mixed up in all of this :
<div class='game-container'>
<div class="penguin1"></div>
<div class="penguin2"></div>
<div class="penguin3"></div>
<div class="penguin4"></div>
<div class="penguin5"></div>
<div class="penguin6"></div>
<div class="penguin7"></div>
<div class="penguin8"></div>
<div class="yeti">
</div>
Shuffling Them Around
This should make them easier to randomize through a simple jQuery extension function like this one mentioned in this related thread :
$.fn.randomize = function(selector){
(selector ? this.find(selector) : this).parent().each(function(){
$(this).children(selector).sort(function(){
return Math.random() - 0.5;
}).detach().appendTo(this);
});
return this;
};
You can combine these two approaches by then simply calling the following when your page has loaded :
$(document).ready(function(){
// Define your randomize function here
// Randomize all of the elements in your container
$('.game-container').randomize('div');
});
Example
$.fn.randomize = function(selector){
(selector ? this.find(selector) : this).parent().each(function(){
$(this).children(selector).sort(function(){
return Math.random() - 0.5;
}).detach().appendTo(this);
});
return this;
};
// Randomize all of the <div> elements in your container
$(".game-container").randomize('div');
.game-container { width: 300px; }
.penguin { background: url('http://vignette1.wikia.nocookie.net/farmville/images/b/be/Baby_Penguin-icon.png/revision/latest?cb=20110103080900'); height: 100px; width: 100px; display: inline-block; }
.yeti { background: url('http://www.badeggsonline.com/beo2-forum/images/avatars/Yeti.png?dateline=1401638613'); height: 100px; width: 100px; display: inline-block; }
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.0/jquery.min.js"></script>
<div class='game-container'>
<div class='penguin'></div>
<div class='penguin'></div>
<div class='penguin'></div>
<div class='penguin'></div>
<div class='penguin'></div>
<div class='penguin'></div>
<div class='penguin'></div>
<div class='yeti'></div>
<div class='penguin'></div>
</div>

<body>
<div class="gameholder">
<div class="title"></div>
<div class="penguin1"></div>
<div class="penguin2"></div>
<div class="penguin3"></div>
<div class="penguin4"></div>
<div class="penguin5"></div>
<div class="penguin6"></div>
<div class="penguin7"></div>
<div class="penguin8"></div>
<div class="yeti"></div>
</div>
<script type="text/javascript">
$(document).ready( function() {
$('.gameholder div').shuffle();
/*
* Shuffle jQuery array of elements - see Fisher-Yates algorithm
*/
jQuery.fn.shuffle = function () {
var j;
for (var i = 0; i < this.length; i++) {
j = Math.floor(Math.random() * this.length);
$(this[i]).before($(this[j]));
}
return this;
};
//This code will run after your page loads
$('body').on('mousedown', '.yeti', function(event) {
alert("Yaaaarrrr!");
});
});
</script>
Here you would like to know what this 2 line of code is doing ->
j = Math.floor(Math.random() * this.length); // (1)
$(this[i]).before($(this[j])); // (2)
Here in line 1 first I am getting random number using Math.random, Math.random gives you floating number ranging from zero to one. so here I am multiplying that number with length, so it gives me random floating number from zero to length, now I am flooring this number to integer, to get integer from zero to length - 1
If we have a selector $('#b').before('#a') then it puts #a element before #b element, so here we are getting one by one element and putting them in the random order.

Add class to an element without an id

I have a list of items:
<div class="crew-item>
<div class="crew-grid"></div>
<div class="crew-detail></div>
</div>
<div class="crew-item>
<div class="crew-grid"></div>
<div class="crew-detail></div>
</div>
<div class="crew-item>
<div class="crew-grid"></div>
<div class="crew-detail></div>
</div>
When I click on a selected 'crew-grid' I'd like to add a class ('active') to its 'crew-item' parent, but I have no idea how to achieve that using vanilla js or jQuery.
The goal is to reveal the 'crew-detail' part, with active class added to its parent.

Like this?:
$('.crew-grid').on('click', function () {
$(this).closest('.crew-item').addClass('active');
});
Basically, starting from the clicked element, get the closest ancestor element which matches that selector. You don't need an id to target an element, just a way to identify it based on the information you have (in this case the clicked element).
If you want to de-activate other elements at the same time:
$('.crew-grid').on('click', function () {
$('.crew-item').removeClass('active');
$(this).closest('.crew-item').addClass('active');
});

Using jQuery :
$('.crew-grid').click(function() {
$(this).closest('.crew-item').addClass('active');
});

Use Document.querySelectorAll()
var crews = document.querySelectorAll('.crew-item');
if (crews) {
for (var i = 0; i < crews.length; i++) {
var grid = crews[i].querySelector('.crew-grid');
grid.addEventListener('click', toggleActive, false);
}
}
function toggleActive() {
var grids = document.querySelectorAll('.crew-item');
for (var i = 0; i < grids.length; i++) {
if (grids[i].classList.contains('active')) {
grids[i].classList.remove('active');
}
}
this.parentNode.classList.add('active');
}
.crew-item.active {
background: #DDD;
}
.crew-grid:hover {
cursor: pointer;
background: #eee;
}
<div class="crew-item active">
<div class="crew-grid">crew-grid</div>
<div class="crew-detail">crew-detail</div>
</div>
<br>
<div class="crew-item">
<div class="crew-grid">crew-grid</div>
<div class="crew-detail">crew-detail</div>
</div>
<br>
<div class="crew-item">
<div class="crew-grid">crew-grid</div>
<div class="crew-detail">crew-detail</div>
</div>