I try to change the color of the navigation bar when the theme change button is clicked.
This is HTML code
<header class="header">
<a href="#">
<img class="logo" alt="logo" src="img/logo.png" />
</a>
<nav class="main-nav" id="main-nav">
<ul class="main-nav-list">
<li>
<a class="main-nav-link" href="#introduction">Intro</a>
</li>
<li>
<a class="main-nav-link" href="#portfolio">Projects</a>
</li>
<li>
<a class="main-nav-link" href="#contact">Hello</a>
</li>
<!-- <li><a class="main-nav-link" href="#">section4</a></li> -->
</ul>
</nav>
</header>
Javascript code
const themeChange = () => {
const navElements = document.getElementsByClassName("main-nav-link");
// console.log("nav: " + navElements.length);
for (let i = 0; i <= navElements.length; i++) {
console.log(document.getElementsByClassName("main-nav-link")[i]);
document.getElementsByClassName("main-nav-link")[i].className =
"main-nav-link-summer";
}
}
I'm trying to change the class name from "main-nav-link" to "main-nav-link-summer" so the color for active, hover can be changed. But weirdly, only the first and third tags are changed and the second remains the same. The length of the "navElements" variable is 3.
CSS code
.main-nav-list {
list-style: none;
display: flex;
gap: 4.8rem;
align-items: center;
/* padding-right: 5rem; */
/* font-size: x-large; */
}
.main-nav-link,
.main-nav-link-summer {
text-decoration: none;
display: inline-block;
color: white;
font-weight: 500;
/* font size 1.8 */
font-size: 2.5rem;
transition: all 0.3s;
}
.main-nav-link-summer:hover,
.main-nav-link-summer:active {
color: #1d4116;
}
.main-nav-link:hover,
.main-nav-link:active {
color: #a63ec5;
}
.sticky {
position: fixed;
top: 0;
bottom: 0;
width: 100%;
height: 8rem;
padding-top: 0;
padding-bottom: 0;
background-color: rgba(255, 255, 255, 0.97);
z-index: 999;
box-shadow: 0 100.2rem 3.2rem rgba(0, 0, 0, 0.03);
opacity: 0.8;
}
.sticky .main-nav-link {
color: #46244c;
}
.sticky .main-nav-link:hover,
.sticky .main-nav-link:active {
color: #a63ec5;
}
in javascript that's the easiest way, for what you wanna achieve I'm not exactly sure.
const navElements = document.querySelectorAll(".main-nav-link");
navElements.forEach((link) => {
link.classList.add("main-nav-link-summer");
});.main-nav-list {
list-style: none;
display: flex;
gap: 4.8rem;
align-items: center;
/* padding-right: 5rem; */
/* font-size: x-large; */
}
.main-nav-link,
.main-nav-link-summer {
text-decoration: none;
display: inline-block;
color: white;
font-weight: 500;
/* font size 1.8 */
font-size: 2.5rem;
transition: all 0.3s;
}
.main-nav-link-summer:hover,
.main-nav-link-summer:active {
color: #1d4116;
}
.main-nav-link:hover,
.main-nav-link:active {
color: #a63ec5;
}
.sticky {
position: fixed;
top: 0;
bottom: 0;
width: 100%;
height: 8rem;
padding-top: 0;
padding-bottom: 0;
background-color: rgba(255, 255, 255, 0.97);
z-index: 999;
box-shadow: 0 100.2rem 3.2rem rgba(0, 0, 0, 0.03);
opacity: 0.8;
}
.sticky .main-nav-link {
color: #46244c;
}
.sticky .main-nav-link:hover,
.sticky .main-nav-link:active {
color: #a63ec5;
}<header class="header">
<a href="#">
<img class="logo" alt="logo" src="img/logo.png" />
</a>
<nav class="main-nav" id="main-nav">
<ul class="main-nav-list">
<li>
<a class="main-nav-link" href="#introduction">Intro</a>
</li>
<li>
<a class="main-nav-link" href="#portfolio">Projects</a>
</li>
<li>
<a class="main-nav-link" href="#contact">Hello</a>
</li>
<!-- <li><a class="main-nav-link" href="#">section4</a></li> -->
</ul>
</nav>
</header>I'd suggest a different approach all together. Going through and doing mass class name changes is really sub-optimal for dev and maintenance. Perhaps consider an approach like the example below instead as a simple proof of concept using separated css var themes so as you build you don't think about such things and can handle a design system much more flexibly without piling on lots of unnecessary extra code. Cheers.
const htmlEl = document.documentElement;
// set a detault or read their saved selection from localstorage or whatever.
htmlEl.dataset.theme = 'default';
// set the new selectiong when made.
toggleTheme = (theme) => htmlEl.dataset.theme = theme;html[data-theme="default"] {
--body-bg: #f1f1f1;
--body-color: #000;
--btn-color: #212121;
--btn-bg: #fff;
--btn-hover-color: #a63ec5;
--btn-hover-bg: #ddd;
}
html[data-theme="summer"] {
--body-bg: lightblue;
--body-color: #000;
--btn-color: darkgreen;
--btn-bg: lightyellow;
--btn-hover-color: #1d4116;
--btn-hover-bg: #f1f1f1;
}
html[data-theme="winter"] {
--body-bg: #333;
--body-color: #fff;
--btn-color: #f1f1f1;
--btn-bg: #212121;
--btn-hover-color: lightblue;
--btn-hover-bg: #555;
}
html {
color: var(--body-color);
background-color: var(--body-bg);
}
.main-nav-list {
list-style: none;
display: flex;
align-items: center;
/* padding-right: 5rem; */
/* font-size: x-large; */
}
.main-nav-link {
text-decoration: none;
display: inline-block;
color: var(--btn-color);
background-color: var(--btn-bg);
padding: .25rem 1rem;
border-radius: 5px;
font-weight: 500;
/* font size 1.8 */
font-size: 2.5rem;
transition: all 0.3s;
}
.main-nav-list li:not(:last-child) {
margin-right: 1.5rem;
}
.main-nav-link:hover,
.main-nav-link:active {
color: var(--btn-hover-color);
background-color: var(--btn-hover-bg);
}<br>
<strong>Choose your theme:</strong>
<select id="mySelect" onchange="toggleTheme(this.value)">
<option value="default">Default</option>
<option value="summer">Summer</option>
<option value="winter">Winter</option>
</select>
<br><hr><br>
<header class="header">
<a href="#">
<img class="logo" alt="logo" src="img/logo.png" />
</a>
<nav class="main-nav" id="main-nav">
<ul class="main-nav-list">
<li>
<a class="main-nav-link" href="#introduction">Intro</a>
</li>
<li>
<a class="main-nav-link" href="#portfolio">Projects</a>
</li>
<li>
<a class="main-nav-link" href="#contact">Hello</a>
</li>
<!-- <li><a class="main-nav-link" href="#">section4</a></li> -->
</ul>
</nav>
</header>