A. Kimberley A. Kimberley - 1 month ago 16
HTML Question

Switching Between Two Slideshows with Javascript

I have a web page with a slideshow. The slideshow has three pictures. I would like to have a button on the page which enables users to switch between this slideshow and another with five different pictures. How would I program this button with JavaScript and where would I add the second slideshow in the HTML?

Current HTML:

<div class="slideshow-container">
<div class="mySlides fade">
<div class="numbertext">1 / 3</div>
<img src="img1.jpg" style="width:100%">
<div class="text">Caption Text</div>
</div>

<div class="mySlides fade">
<div class="numbertext">2 / 3</div>
<img src="img2.jpg" style="width:100%">
<div class="text">Caption Two</div>
</div>

<div class="mySlides fade">
<div class="numbertext">3 / 3</div>
<img src="img3.jpg" style="width:100%">
<div class="text">Caption Three</div>
</div>

<a class="prev" onclick="plusSlides(-1)">&#10094;</a>
<a class="next" onclick="plusSlides(1)">&#10095;</a>
</div>
<br>

<div style="text-align:center">
<span class="dot" onclick="currentSlide(1)"></span>
<span class="dot" onclick="currentSlide(2)"></span>
<span class="dot" onclick="currentSlide(3)"></span>
</div>
<button>Switch Slideshow</button>


Current CSS:

/* Slideshow container */
.slideshow-container {
max-width: 1000px;
position: relative;
margin: auto;
}

/* Next & previous buttons */
.prev, .next {
cursor: pointer;
position: absolute;
top: 50%;
width: auto;
margin-top: -22px;
padding: 16px;
color: white;
font-weight: bold;
font-size: 18px;
transition: 0.6s ease;
border-radius: 0 3px 3px 0;
}

/* Position the "next button" to the right */
.next {
right: 0;
border-radius: 3px 0 0 3px;
}

/* On hover, add a black background color with a little bit see-through */
.prev:hover, .next:hover {
background-color: rgba(0,0,0,0.8);
}

/* Caption text */
.text {
color: #f2f2f2;
font-size: 15px;
padding: 8px 12px;
position: absolute;
bottom: 8px;
width: 100%;
text-align: center;
}

/* Number text (1/3 etc) */
.numbertext {
color: #f2f2f2;
font-size: 12px;
padding: 8px 12px;
position: absolute;
top: 0;
}

/* The dots/bullets/indicators */
.dot {
cursor:pointer;
height: 13px;
width: 13px;
margin: 0 2px;
background-color: #bbb;
border-radius: 50%;
display: inline-block;
transition: background-color 0.6s ease;
}

.active, .dot:hover {
background-color: #717171;
}

/* Fading animation */
.fade {
-webkit-animation-name: fade;
-webkit-animation-duration: 1.5s;
animation-name: fade;
animation-duration: 1.5s;
}

@-webkit-keyframes fade {
from {opacity: .4}
to {opacity: 1}
}

@keyframes fade {
from {opacity: .4}
to {opacity: 1}
}


Current JavaScript:

var slideIndex = 1;
showSlides(slideIndex);

function plusSlides(n) {
showSlides(slideIndex += n);
}

function currentSlide(n) {
showSlides(slideIndex = n);
}

function showSlides(n) {
var i;
var slides = document.getElementsByClassName("mySlides");
var dots = document.getElementsByClassName("dot");
if (n > slides.length) {slideIndex = 1}
if (n < 1) {slideIndex = slides.length}
for (i = 0; i < slides.length; i++) {
slides[i].style.display = "none";
}
for (i = 0; i < dots.length; i++) {
dots[i].className = dots[i].className.replace(" active", "");
}
slides[slideIndex-1].style.display = "block";
dots[slideIndex-1].className += " active";
}


Many thanks in advance!

Answer

Well, you need to first be able to create your slideshow dynamically. Only then will you be able to swap in-and-out different slides. I tried not to refactor your existing code. Also, I did not use jQuery (which I would use personally). Just generate the markup for each slide and set it on the slides div. I had to create an inner div so that the buttons do not get overridden.

var slideshowIndex = 1;
var slideIndex = 1;
var slideshows = [
  [
    'http://placehold.it/500x300/f00/0ff?text=Foo',
    'http://placehold.it/500x300/0f0/f0f?text=Bar',
    'http://placehold.it/500x300/00f/ff0?text=Baz'
  ], [
    'http://placehold.it/500x300/f70/07f?text=Fizz',
    'http://placehold.it/500x300/0f7/f07?text=Buzz',
    'http://placehold.it/500x300/70f/7f0?text=Bang'
  ]
];
function createSlides(slides) {
  return slides.map(function(slide, index) {
    return [
      '<div class="mySlides fade">',
      '<div class="numbertext">' + (index + 1) + ' / ' + slides.length + '</div>',
      '<img src="' + slide + '">',
      '<div class="text">Caption #' + (index + 1) + '</div>',
      '</div>'
    ].join('');
  }).join('');
}
function createDots(slides) {
  return slides.map(function(slide, index) {
    return '<span class="dot" onclick="currentSlide(' + (index + 1) + ')"></span>'
  }).join('');
}
function loadSlideshow(slides) {
  document.getElementsByClassName('slideshow-slides')[0].innerHTML = createSlides(slides);
  document.getElementsByClassName('dots')[0].innerHTML = createDots(slides);
}
function loadNextSlideshow() {
  slideshowIndex = (slideshowIndex + 1) % 2;
  loadSlideshow(slideshows[slideshowIndex]);
  slideIndex = 1; // Reset index
  showSlides(slideIndex);
}

loadNextSlideshow(); // Load the slideshow

function plusSlides(n) {
  showSlides(slideIndex += n);
}
function currentSlide(n) {
  showSlides(slideIndex = n);
}
function showSlides(n) {
  var i;
  var slides = document.getElementsByClassName("mySlides");
  var dots = document.getElementsByClassName("dot");
  if (n > slides.length) {
    slideIndex = 1
  }
  if (n < 1) {
    slideIndex = slides.length
  }
  for (i = 0; i < slides.length; i++) {
    slides[i].style.display = "none";
  }
  for (i = 0; i < dots.length; i++) {
    dots[i].className = dots[i].className.replace(" active", "");
  }
  slides[slideIndex - 1].style.display = "block";
  dots[slideIndex - 1].className += " active";
}
/* Slideshow container */
.slideshow-container {
  max-width: 1000px;
  position: relative;
  margin: auto;
}

/* Next & previous buttons */
.prev, .next {
  cursor: pointer;
  position: absolute;
  top: 50%;
  width: auto;
  margin-top: -22px;
  padding: 16px;
  color: white;
  font-weight: bold;
  font-size: 18px;
  transition: 0.6s ease;
  border-radius: 0 3px 3px 0;
  text-shadow: 0.05em 0.05em 0.25em #000;
}

/* Position the "next button" to the right */
.next {
  right: 0;
  border-radius: 3px 0 0 3px;
}

/* On hover, add a black background color with a little bit see-through */
.prev:hover, .next:hover {
  background-color: rgba(0, 0, 0, 0.8);
}

/* Caption text */
.text {
  color: #f2f2f2;
  font-size: 15px;
  padding: 8px 12px;
  position: absolute;
  bottom: 8px;
  width: 100%;
  text-align: center;
}

/* Number text (1/3 etc) */
.numbertext {
  color: #f2f2f2;
  font-size: 12px;
  padding: 8px 12px;
  position: absolute;
  top: 0;
}

/* The dots/bullets/indicators */
.dot {
  cursor: pointer;
  height: 13px;
  width: 13px;
  margin: 0 2px;
  background-color: #bbb;
  border-radius: 50%;
  display: inline-block;
  transition: background-color 0.6s ease;
}
.active, .dot:hover {
  background-color: #717171;
}

/* Fading animation */
.fade {
  -webkit-animation-name: fade;
  -webkit-animation-duration: 1.5s;
  animation-name: fade;
  animation-duration: 1.5s;
}

@-webkit-keyframes fade {
  from { opacity: 0.4 }
  to   { opacity: 1 }
}
@keyframes fade {
  from { opacity: 0.4 }
  to   { opacity: 1 }
}
<div class="slideshow-container">
  <div class="slideshow-slides"></div>
  <a class="prev" onClick="plusSlides(-1)">&#10094;</a>
  <a class="next" onClick="plusSlides(1)">&#10095;</a>
</div>
<br />
<div class="dots" style="text-align:center"></div>
<button class="switch" onClick="loadNextSlideshow()">Switch Slideshow</button>