How to solve js script not showing / working on mobile - javascript

I'm creating a slider where I use a small script. With this script the slides get an additional styling (display block or none). On browser this works just fine, but on mobile it won't give the slides the additional styling. I heared that it might be the 'let' elements, but changing this to 'var' wont make a difference. Anyone knows what to improve to make this working?
Btw: testing on an iPhone 11 with IOS 15.6 (both firefox and safari)
<script>
let slides = document.getElementsByClassName("mySlides");
let dots = document.getElementsByClassName("dot");
let prev = document.querySelector(".prev");
let next = document.querySelector(".next");
if (!slides.length == 0) {
let slideIndex = 1;
showSlides(slideIndex);
function plusSlides(n) {
showSlides((slideIndex += n));
}
let currentSlide = function (n) {
showSlides((slideIndex = n));
};
function showSlides(n) {
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-dot", "");
}
slides[slideIndex - 1].style.display = "block";
dots[slideIndex - 1].className += " active-dot";
}
}
prev.addEventListener("click", () => {
plusSlides(-1);
});
next.addEventListener("click", () => {
plusSlides(1);
});
</script>

Related

JS slider code cannot reach the value of created element

I try to settle a slider on my html page. But my slider cannot reach the element that is created by the other js code. I am working with modules.
The code block below comes from UI.js file
static createSliderBtn(){
let slider2 = document.querySelector(".slideshow-container");
slider2.innerHTML = `
<a id="prev" >❮</a>
<a id="next" >❯</a>
`;
}
And try to run it with my slider code in project.JS
function prevSlides() {
showSlides((slideIndex += 1));
console.log("prevSlides is triggered");
}
function nextSlides() {
showSlides((slideIndex += -1));
console.log("prevSlides is triggered");
}
function currentSlide(n) {
showSlides((slideIndex = n));
}
function showSlides(n) {
let i;
let slides = document.querySelectorAll(".mySlides");
let dots = document.querySelectorAll(".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";
}
and try to trigger tese A elements in order to navigate sliders in project.JS
const prvBtn = document.querySelector("#prev");
const nxtBtn = document.querySelector("#next");
eventListener();
function eventListener() {
prvBtn.addEventListener("click", prevSlides);
nxtBtn.addEventListener("click", nextSlides);
}
But when I run my code, my browser gives this error Uncaught TypeError: prvBtn is null

how to implement automatic and manual slider using jquery and also pause the slider on hover

I have implemented automatic and manual image slider together. But I also want to pause the automatic sliding on hover. How can i do this. Here is the code snippet. No external libraries other than jQuery.
var slideIndex = 0;
var slides = document.getElementsByClassName("mySlides");
showSlides();
function showSlides() {
var i;
for (i = 0; i < slides.length; i++) {
slides[i].style.display = "none";
}
slideIndex++;
if (slideIndex> slides.length) {slideIndex = 1}
slides[slideIndex-1].style.display = "block";
setTimeout(showSlides, 5000); // Change image every 5 seconds
}
function currentSlide(no) {
var i;
for (i = 0; i < slides.length; i++) {
slides[i].style.display = "none";
}
slideIndex = no;
slides[no-1].style.display = "block";
}
function plusSlides(n) {
var newslideIndex = slideIndex + n;
if(newslideIndex < 4 && newslideIndex > 0){
currentSlide(newslideIndex);
}
}

Slideshow Javascript

Hi I have a slideshow javascript running on my website but it doesn't seem to be working properly when I change the images back and forth and the automaticity doesn't show image 6. Could someone please help me write it up because I have been trying over a month and reached nowhere.
https://wbd-ownwork-13--15nalaas.repl.co/
<script>
var slideIndex = 1;
showSlides(slideIndex);
// Next/previous controls
function plusSlides(n) {
showSlides(slideIndex += n);
}
// Thumbnail image controls
function currentSlide(n) {
showSlides(slideIndex = n);
}
function showSlides(n) {
var i;
var slides = document.getElementsByClassName("mySlides");
var dots = document.getElementsByClassName("demo");
var captionText = document.getElementById("caption");
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";
captionText.innerHTML = dots[slideIndex-1].alt;
}
var slideIndex = 0;
showSlides();
function showSlides() {
var i;
var slides = document.getElementsByClassName("mySlides");
for (i = 0; i < slides.length; i++) {
slides[i].style.display = "none";
}
slideIndex++;
if (slideIndex > slides.length) {slideIndex = 2}
slides[slideIndex-2].style.display = "block";
setTimeout(showSlides, 4000); // Change image every 4 seconds
}
</script>
First of all you need not to add the custom controls for changing the slides because the slide show is more than enough.
And secondly you need to change the entire script to the given script only then it is going to work because rest of your script is messing with the slideshow.
Change the entire script from line 94 to line 125 in your HTML to this -
<script>
var slideIndex = 0;
showSlides();
function showSlides(){
var slides = document.querySelectorAll('.mySlides');
for(var i = 0; i < slides.length; i++){
slides[i].style.display = "none";
}
slides[slideIndex].style.display = "block";
slideIndex++;
if(slideIndex > slides.length - 1){slideIndex = 0}
loop();
}
function loop(){
setTimeout(showSlides, 1000);
}
</script>
If still you have a problem the please ask again.

slides hidden on page load, but becomes visible after clicking on dots

It seems there is some error in javascript, please help.
Slides are not visible at page load, but appears o click of dot.
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";
}
You are defining all the functions for sliding but it doesn't look like you are calling any of them until a click. Try adding
showSlides() below your code.
Asif Vk could you demonstrate in JSFiddle?

javascript automatic image slides

i want to make slide images to automatically replace. Here is code i use for manual replacing by clicking on buttoms. Sorry if it is some basics issue, but i don't realy use javascript. I've got it from w3schools, and try to combine the automatic replacing and this, but didn't work.
Thanks for answers.
PS: There are 3 images now and 4 will be.
var slideIndex = 1;
showDivs();
function plusDivs(n) {
showDivs(slideIndex += n);
}
function currentDiv(n) {
showDivs(slideIndex = n);
}
function showDivs(n) {
var i;
var x = document.getElementsByClassName("mySlides");
var dots = document.getElementsByClassName("demo");
if (n > x.length) {slideIndex = 1}
if (n < 1) {slideIndex = x.length}
for (i = 0; i < x.length; i++) {
x[i].style.display = "none";
}
for (i = 0; i < dots.length; i++) {
dots[i].className = dots[i].className.replace(" w3-white", "");
}
x[slideIndex-1].style.display = "block";
dots[slideIndex-1].className += " w3-white";
x[slideIndex-1].style.width = "784px";
x[slideIndex-1].style.height = "350px";
}
The thing you need to do is continuously call the function for changing the slides in certain intervals. I am adding the complete code after making changes for the same.
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";
}
var slides = document.getElementsByClassName("mySlides");
var dots = document.getElementsByClassName("dot");
var index = 0;
setInterval(function() {
index++;
if( self.index == self.slides.length ) {
index = 0;
}
currentSlide( index );
}, 2000);
Instead of 2000, you can give any delay you need. Think this solves your problem.

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