Javascript: website header slideshow fade-in effect

Question

Since this is one rather long question-thank in advance to those who bother to read it! I am doing a personal blog website project, and in the index page, I want to achieve a slideshow header (contains a background picture, a title and a button redirecting user to the actual psot) to display featured blog posts dynamically. I also wanted fade-in effect when the header transform into another one. My html for the header looks like this:

var slideIndex = 0;

function carousel() {
  var i;
  var x = document.getElementsByClassName("header-slide");
  for (i = 0; i < x.length; i++) {
    x[i].style.opacity = 0;
    x[i].style.display = "none";
  }
  slideIndex++;
  if (slideIndex > x.length) {
    slideIndex = 1;
  }
  x[slideIndex - 1].style.opacity = 1;
  x[slideIndex - 1].style.display = "block";
  setTimeout(carousel, 3000);
}

.header-1 {
  background-image: linear-gradient(rgba(0, 0, 0, 0.29), #000), url(background-image#1);
  background-size: cover;
  background-position: center;
  background-attachment: fixed;
  height: 100vh;
}

.header-2 {
  background-image: linear-gradient(rgba(0, 0, 0, 0.29), #000), url(background-image#2);
  background-size: cover;
  background-position: center;
  background-attachment: fixed;
  height: 100vh;
}

.header-3 {
  background-image: linear-gradient(rgba(0, 0, 0, 0.29), #000), url(background-image#3);
  background-size: cover;
  background-position: center;
  background-attachment: fixed;
  height: 100vh;
}

.header-style {
  display: none;
  transition: opacity .5s ease-in;
}

<div class="slideshow-container">
  <div class="header-slide">
    <header class="header-1">
      <nav>
        <div class="row">
          <ul class="main-nav">
            <li><a href="article_directory.html">Articles</a></li>
            <li><a href="http://collegiatecycling.org/accc/">Collegiate Racing</a></li>
            <li><a href="photo_gallery.html">Multimedia</a></li>
            <li><a href="current_projects.html">Current Porjects</a></li>
            <li><a href="get_in_touch.php">Get in touch</a></li>
            <li><a href="#first-footer-child">External</a></li>
          </ul>
        </div>
      </nav>
      <div class="hero-text-box">
        <h1>Article#1</h1>
        <a class="btn btn-full" href="#">Read full story</a>
      </div>
    </header>
  </div>

  <div class="header-slide">
    <header class="header-2">
      <nav>
        <div class="row">
          <ul class="main-nav">
            <li><a href="article_directory.html">Articles</a></li>
            <li><a href="http://collegiatecycling.org/accc/">Collegiate Racing</a></li>
            <li><a href="photo_gallery.html">Multimedia</a></li>
            <li><a href="current_projects.html">Current Porjects</a></li>
            <li><a href="get_in_touch.php">Get in touch</a></li>
            <li><a href="#first-footer-child">External</a></li>
          </ul>
        </div>
      </nav>
      <div class="hero-text-box">
        <h1>Article#2</h1>
        <a class="btn btn-full" href="#">Read more</a>
      </div>
    </header>
  </div>

  <div class="header-slide">
    <header class="header-3">
      <nav>
        <div class="row">
          <ul class="main-nav">
            <li><a href="article_directory.html">Articles</a></li>
            <li><a href="http://collegiatecycling.org/accc/">Collegiate Racing</a></li>
            <li><a href="photo_gallery.html">Multimedia</a></li>
            <li><a href="current_projects.html">Current Porjects</a></li>
            <li><a href="get_in_touch.php">Get in touch</a></li>
            <li><a href="#first-footer-child">External</a></li>
          </ul>
        </div>
      </nav>
      <div class="hero-text-box">
        <h1>Article#3</h1>
        <a class="btn btn-full" href="#">Read more</a>
      </div>
    </header>
  </div>
</div>

I already have the following js script, which, while embedded in the html file, does slideshow the header, but fails to achieve a fade-in effect.

I want the fade-in effect as well, so I added the following CSS codes.

With all the above measures, my website header still fails to slideshow in with fade-in effect. My question is, it seems setting the transition property doesn't change anything, as the header opacity is changed by my js script (so every time it changes from 0 to 1, the CSS would handle how it changes)? Any assistance appreciated!

NVRM · Accepted Answer · 2019-01-25T22:36:47.123

Using css keyframe animation:

#header {
  animation: fade 5s ease-out infinite;
}

@keyframes fade {
  0% {
     opacity: .1
  }
  100% {
     opacity: 1
  }
}

<div id="header">
<img src="https://c1.staticflickr.com/5/4016/4543539771_1325623dd6.jpg"></img>
</div>

Or have a look at the browser native animation api:

The Web Animations API opens the browser’s animation engine to developers and manipulation by JavaScript.

This API was designed to underlie implementations of both CSS Animations and CSS Transitions, and leaves the door open to future animation effects.

It is one of the most performant ways to animate on the Web where supported, letting the browser make its own internal optimizations without hacks

https://developer.mozilla.org/en-US/docs/Web/API/Web_Animations_API/Using_the_Web_Animations_API

https://stackoverflow.com/a/53785137/2494754

Thanks! Yeah that solves the problem and gives a very nice fade-in effect as long as the js time interval is greater than that of CSS. — HL1701, Jun 12 '18 at 17:10

Javascript: website header slideshow fade-in effect

1 Answers1