点击按钮切换父元素的类-纯javascript

Question

我在页面上有多个div类'item' -我想在div中包含一个按钮，当单击时将切换追加/删除'item'div上的'zoom'类…

<div class="item">
<button class="zoomer"></button>
</div>

我已经找到了大量的代码示例，目标是一个id元素，但很难找到一个解决方案，工作与多个相同的类元素在一个页面上。

提前感谢!

Answer 1

您可以使用querySelectorAll来获取所有的buttons，然后您可以使用forEach，以便您可以针对元素的item父元素。

// Get all the buttons
let zoomer_button = document.querySelectorAll('.zoomer');
// Loop through the buttons.
// Arrow function allows to pass the element
zoomer_button.forEach(button => {
// Add an event listener for a click on the button.
button.addEventListener('click', function(e) {
// the e is the event, and then you check what the target is, which is the button.
// then you can toggle a 'zoom' class on the parent 'item'
e.target.parentNode.classList.toggle('zoom');
});
});

.item.zoom {
background-color: blue;
}

<div class="item">
<button class="zoomer">button</button>
</div>
<div class="item">
<button class="zoomer">button</button>
</div>
<div class="item">
<button class="zoomer">button</button>
</div>
<div class="item">
<button class="zoomer">button</button>
</div>
<div class="item">
<button class="zoomer">button</button>
</div>

如果它嵌套更深一层，你可以使用parentNode两次。

// Get all the buttons
let zoomer_button = document.querySelectorAll('.zoomer');
// Loop through the buttons.
// Arrow function allows to pass the element
zoomer_button.forEach(button => {
// Add an event listener for a click on the button.
button.addEventListener('click', function(e) {
// the e is the event, and then you check what the target is, which is the button.
// then you can toggle a 'zoom' class on the parent 'item'
e.target.parentNode.parentNode.classList.toggle('zoom');
});
});

.item.zoom {
background-color: blue;
}

<div class="item">
<div class="media">
<button class="zoomer">button</button>
</div>
</div>
<div class="item">
<div class="media">
<button class="zoomer">button</button>
</div>
</div>
<div class="item">
<div class="media">
<button class="zoomer">button</button>
</div>
</div>
<div class="item">
<div class="media">
<button class="zoomer">button</button>
</div>
</div>

Answer 2

您可以使用querySelectorAll并使用e.target

访问每个元素

document.querySelectorAll('.item > .zoomer')
.forEach(elem => elem.addEventListener('click', e => {

e.target.classList.toggle('someClass')
}))

.someClass{
background:limegreen;
}

<div class="item">
<button class="zoomer">1</button>
</div>
<div class="item">
<button class="zoomer">2</button>
</div>
<div class="item">
<button class="zoomer">3</button>
</div>
<div class="item">
<button class="zoomer">4</button>
</div>

Answer 3

在下面的例子中，有7个<button>s做不同的事情——细节在例子中有注释。

// Render 7 <menu>/<button> combos 
[...new Array(7)].forEach((item, index) => {
document.querySelector('main').insertAdjacentHTML('beforeend', `
<menu class="item${index}">
<button class="btn${index}">${index}</button>
</menu>`);
});
/*~~~~~~~~~~~~~~~~~~~~~~~.btn0*/
// Click <button> remove it's parent (which also removes the <button>)
document.querySelector('.btn0').onclick = function(e) {
this.parentElement.remove();
}
/*~~~~~~~~~~~~~~~~~~~~~~~.btn1*/
// Click <button> -- <button> is removed but it's contents is left behind
document.querySelector('.btn1').onclick = unWrap;
function unWrap(e) {
const clicked = e.target;
const parent = clicked.parentElement;
while (clicked.firstChild) {
parent.insertBefore(clicked.firstChild, clicked);
}
clicked.remove();
}
/*~~~~~~~~~~~~~~~~~~~~~.btn4-6*/
// Collect all tags with a class that starts with "btn"
const btns = document.querySelectorAll("[class^='btn']");
// Adding .target class to the last 2 <button>s
btns.forEach((btn, idx) => {
if (idx > 4) btn.classList.add('target')
});
/*~~~~~~~~~~~~~~~~~~~~~~~.btn2*/
// Target third <button> by index
/*
When <button> clicked, it's parent gets .hide class which is:
visibility:hidden which would normally hide the <button> as well, but
.btn2 has visibility explicitly set to visible
*/
btns[2].onclick = e => e.target.closest('menu').classList.toggle('hide');
/*~~~~~~~~~~~~~~~~~~~~~~~.btn3*/
/*
Everytime the <button> is clicked, a copy of itself is made and the
clones also have this ability as well
*/
btns[3].addEventListener('click', copySelf);
function copySelf(e) {
let dupe = e.target.cloneNode(true);
e.target.parentElement.append(dupe);
dupe.onclick = copySelf;
}
/*~~~~~~~~~~~~~~~~~~~~~.btn4-6*/
/*
The click event is bound to the parent/ancestor tag <section>
Any click to any <button> will trigger the event handler. 
.btn4, .btn5, and .btn6 all react in a specific manner because
the event handler, delegateClick(e) is using flow control statements and 
specific criteria.
*/
document.querySelector('main').onclick = delegateClick;
let armed = false;
function delegateClick(e) {
const clicked = e.target;
if (clicked.matches('button') && !armed) {
clicked.classList.add('armed');
armed = true;
return;
}
if (clicked.matches('.armed.target') && armed) {
clicked.parentElement.style.cssText = `font-size: 5rem; margin: 0`
clicked.replaceWith(`💥`);
return;
}
if (clicked.matches('.target') && armed) {
clicked.classList.add('armed');
return;
}
if (clicked.matches('.armed') && armed) {
clicked.classList.remove('armed');
armed = false;
}
}

menu {
outline: dashed red 1px;
}
.hide {
visibility: hidden;
}
.btn2 {
visibility: visible
}
.armed {
animation: warning 1s linear infinite;
}
@keyframes warning {
50% {
opacity: 0;
}
}
.target.armed {
background: red;
color: white;
}
button {
font: inherit;
cursor: pointer;
}

<main></main>