Javascript: Image does not get updated immediately - javascript

I'm trying to learn Javascript from the book Head First Javascript (Morrison).
Inside the function findSeat(), the code is supposed to update the image to 'seat_select.png' for every seat that is available and then ask for a confirmation.
However, when I run the code, the images are updated immediately (as expected) only sometimes. Otherwise, the images are updated only after the loop has completed.
Why is this happening?
<html>
<head>
<title>Movie Ticket Finder</title>
<script type="text/javascript">
var seats = [ false, true, false, true, true, true, false, true, false ];
var selSeat = -1;
function initSeats() {
// Initialize the appearance of all seats
for (var i = 0; i < seats.length; i++) {
if (seats[i]) {
// Set the seat to available
document.getElementById("seat" + i).src = "seat_avail.png";
document.getElementById("seat" + i).alt = "Available seat";
}
else {
// Set the seat to unavailable
document.getElementById("seat" + i).src = "seat_unavail.png";
document.getElementById("seat" + i).alt = "Unavailable seat";
}
}
}
function findSeat() {
// If seat is already selected, reinitialize all seats to clear them
if (selSeat >= 0) {
selSeat = -1;
initSeats();
}
// Search through all the seats for availability
for (var i = 0; i < seats.length; i++) {
// See if the current seat is available
if (seats[i]) {
// Set the seat selection and update the appearance of the seat
selSeat = i;
document.getElementById("seat" + i).src = "seat_select.png";
document.getElementById("seat" + i).alt = "Your seat";
// Prompt the user to accept the seat
var accept = confirm("Seat " + (i + 1) + " is available. Accept?");
if (!accept) {
// The user rejected the seat, so clear the seat selection and keep looking
selSeat = -1;
document.getElementById("seat" + i).src = "seat_avail.png";
document.getElementById("seat" + i).alt = "Available seat";
}
}
}
}
</script>
</head>
<body onload="initSeats();">
<div style="margin-top:75px; text-align:center">
<img id="seat0" src="" alt="" />
<img id="seat1" src="" alt="" />
<img id="seat2" src="" alt="" />
<img id="seat3" src="" alt="" />
<img id="seat4" src="" alt="" />
<img id="seat5" src="" alt="" />
<img id="seat6" src="" alt="" />
<img id="seat7" src="" alt="" />
<img id="seat8" src="" alt="" /><br />
<input type="button" id="findseat" value="Find Seat" onclick="findSeat();" />
</div>
</body>
</html>
EDIT: Based on Oleg Yudovich's answer, this is what I added to my code. Now everything works as expected!
<div style="display: none">
<img id="seat_unavail" src="seat_unavail.png" alt="" />
<img id="seat_avail" src="seat_avail.png" alt="" />
<img id="seat_select" src="seat_select.png" alt="" />
</div>

Once you include new image in your html, your browser is download this image and put it to cache, before displaying.This process is take time. If your images is big size, is take more time. So you can solve your problem by caching images before your loop is start running :
<div style="display:none;">
<img id="seat0" src="some image source" alt=""/>
<img id="seat0" src="some image source" alt=""/>
<img id="seat0" src="some image source" alt=""/>
<img id="seat0" src="some image source" alt=""/>
<img id="seat0" src="some image source" alt=""/>
<img id="seat0" src="some image source" alt=""/>
</div>
This hidden block,if you put him on your site start page, will load all images into browser cache.

Related

How i can Set Up my Gallery Pagination correctly?

How can I set up my gallery pagination correctly?
I'm using this code below but when I change the page, leaves blank spaces and when I'm at the last gallery page and press the next page again, it goes to the first gallery page again.
I'm trying to use this Pagination but I don't know how to set up it, what should I put on ''#demo'' and on var html = template(data); to make the page pagination working on my gallery?
var start = 0;
var nb = 3;
var end = start + nb;
var length = $('.gallery img').length;
var list = $('.gallery img');
list.hide().filter(':lt('+(end)+')').show();
$('.prev, .next').click(function(e){
e.preventDefault();
if( $(this).hasClass('prev') ){
start -= nb;
} else {
start += nb;
}
if( start < 0 || start >= length ) start = 0;
end = start + nb;
if( start == 0 ) list.hide().filter(':lt('+(end)+')').show();
else list.hide().filter(':lt('+(end)+'):gt('+(start-1)+')').show();
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<div class="gallery">
<img src="IMG_1.JPG" alt="IMG 1" width="auto" height="auto">
<img src="IMG_2.JPG" alt="IMG 2" width="auto" height="auto">
<img src="IMG_3.JPG" alt="IMG 3" width="auto" height="auto">
<img src="IMG_4.JPG" alt="IMG 4" width="auto" height="auto">
<img src="IMG_5.JPG" alt="IMG 5" width="auto" height="auto">
<img src="IMG_6.JPG" alt="IMG 6" width="auto" height="auto">
</div>
<div style="clear: both;"></div>
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Multiple Image Slideshow Javascript Issue

I have 4 image slideshows, and I am having trouble with the Javascript. I have given the div both an id and a class name. The class imageContainer is used in the CSS. Therefore I am using id for the Javascript, but it won't work. I can do this with one image slideshow, but I need to have multiple slideshows on the same page.
The HTML code below is not my actual code, it is just placeholder code I wrote to show what I want to achieve. The Javascript code, however, is my actual code.
I appreciate the help.
function openWin(url) {
aWindow = window.open(url, "Window 1", "width=400, height=400");
}
var numslides = 0,
currentslide = 0;
var slides = new Array();
function MakeSlideShow() {
container = document.getElementsById("Gallery");
for (i = 0; i < imgs.length; i++) {
if (imgs[i].className != "imga") continue;
slides[numslides] = imgs[i];
if (numslides == 0) {
imgs[i].style.display = "block";
} else {
imgs[i].style.display = "none";
}
imgs[i].onclick = NextSlide;
numslides++;
}
}
function NextSlide() {
slides[currentslide].style.display = "none";
currentslide++;
if (currentslide >= numslides) currentslide = 0;
slides[currentslide].style.display = "block";
}
window.onload = MakeSlideShow;
<h2>Gallery 1</h2>
<div id="Gallery" class="imageContainer">
<img class="img" src="https://via.placeholder.com/100" />
<img class="img" src="https://via.placeholder.com/101" />
<img class="img" src="https://via.placeholder.com/102" />
<img class="img" src="https://via.placeholder.com/103" />
</div>
<h2>Gallery 2</h2>
<div id="Gallery" class="imageContainer">
<img class="img" src="https://via.placeholder.com/106" />
<img class="img" src="https://via.placeholder.com/107" />
<img class="img" src="https://via.placeholder.com/108" />
<img class="img" src="https://via.placeholder.com/109" />
</div>
<h2>Gallery 3</h2>
<div id="Gallery" class="imageContainer">
<img class="img" src="https://via.placeholder.com/110" />
<img class="img" src="https://via.placeholder.com/111" />
<img class="img" src="https://via.placeholder.com/112" />
<img class="img" src="https://via.placeholder.com/113" />
</div>
<h2>Gallery 4</h2>
<div id="Gallery" class="imageContainer">
<img class="img" src="https://via.placeholder.com/114" />
<img class="img" src="https://via.placeholder.com/115" />
<img class="img" src="https://via.placeholder.com/116" />
<img class="img" src="https://via.placeholder.com/117" />
</div>
ID's must be unique, so, the best way to do this is get all galleries by their class name and start getting images from there. Note that slides is now a bidimensional array to hold gallery and images, something like:
slides[0] = [image100, image101, image102, image103];
I've added indexes for gallery and image to each picture using dataset propperty, so, you only need to know wich image was clicked instead of trying to get from currentslide. Also, numslides is provided from gallery length.
var slides = new Array();
function MakeSlideShow()
{
var containers = document.getElementsByClassName("imageContainer");
for(var x = 0; x < containers.length; x++) {
// Create gallery
slides[x] = new Array();
var imgs = containers[x].children;
for(var i = 0; i < imgs.length; i++) {
// Add image to current gallery
slides[x][i] = imgs[i];
// Set it's display, note that at least 1 images was added
if(slides[x].length == 1) {
imgs[i].style.display = 'block';
} else {
imgs[i].style.display = 'none';
}
// Add gallery and image info
imgs[i].dataset.gallery = x;
imgs[i].dataset.img = i;
// Add onclick event, but we need to send current image
imgs[i].onclick = function() {
nextSlide(this);
}
}
}
}
// This function needs to know wich img was clicked
function nextSlide(pic)
{
// Get gallery and image from dataset to know what to do
var gallery = pic.dataset.gallery;
var img = pic.dataset.img;
// Hide current image
slides[gallery][img].style.display = 'none';
// Search for next
img ++;
// No more images availabel, go to first
if(img == slides[gallery].length) {
img = 0;
}
// Show next image
slides[gallery][img].style.display = 'block';
}
window.onload = MakeSlideShow;
<h2>Gallery 1</h2>
<div id="Gallery1" class="imageContainer">
<img class="img" src="https://via.placeholder.com/100" />
<img class="img" src="https://via.placeholder.com/101" />
<img class="img" src="https://via.placeholder.com/102" />
<img class="img" src="https://via.placeholder.com/103" />
</div>
<h2>Gallery 2</h2>
<div id="Gallery2" class="imageContainer">
<img class="img" src="https://via.placeholder.com/106" />
<img class="img" src="https://via.placeholder.com/107" />
<img class="img" src="https://via.placeholder.com/108" />
<img class="img" src="https://via.placeholder.com/109" />
</div>
<h2>Gallery 3</h2>
<div id="Gallery3" class="imageContainer">
<img class="img" src="https://via.placeholder.com/110" />
<img class="img" src="https://via.placeholder.com/111" />
<img class="img" src="https://via.placeholder.com/112" />
<img class="img" src="https://via.placeholder.com/113" />
</div>
<h2>Gallery 4</h2>
<div id="Gallery4" class="imageContainer">
<img class="img" src="https://via.placeholder.com/114" />
<img class="img" src="https://via.placeholder.com/115" />
<img class="img" src="https://via.placeholder.com/116" />
<img class="img" src="https://via.placeholder.com/117" />
</div>

Random logo in a grid

I would like to create in jQuery a "wall" of logo like on the https://www.squarespace.com/ website at the "TRUSTED BY THE WORLD’S BEST" section.
The same thing : 8 logos with fade-in fade-out.
Can I have some help please ?
<div class="client-logos-grid">
<img src="" alt="">
<img src="" alt="">
<img src="" alt="">
<img src="" alt="">
<img src="" alt="">
<img src="" alt="">
<img src="" alt="">
<img src="" alt="">
</div>
I begin with this : https://jsfiddle.net/vc43mzxL/1/
$('document').ready(function() {
var curIndex = 0;
var src = ['http://www.jqueryscript.net/images/Simplest-Responsive-jQuery-Image-Lightbox-Plugin-simple-lightbox.jpg', 'http://www.jqueryscript.net/images/Simplest-Responsive-jQuery-Image-Lightbox-Plugin-simple-lightbox.jpg', 'http://www.jqueryscript.net/images/Simplest-Responsive-jQuery-Image-Lightbox-Plugin-simple-lightbox.jpg'];
var fadeTimeInMilliseconds = 2000;
var waitTimeInMilliseconds = 5000;
$(document).ready(function() {
switchImageAndWait(true);
});
function switchImageAndWait(fadeOut2) {
if (fadeOut2) {
setTimeout(fadeOut, waitTimeInMilliseconds);
} else {
var index = Math.floor((Math.random() * src.length))
if (curIndex == index) {
index++;
if (index >= src.length) {
index -= 8;
}
}
curIndex = index;
$(".client-logo img").attr("src", src[index]);
fadeIn();
}
}
function fadeOut() {
$(".client-logo img").fadeTo(fadeTimeInMilliseconds, 0, function() {
switchImageAndWait(false);
});
}
function fadeIn() {
$(".client-logo img").fadeTo(fadeTimeInMilliseconds, 1, function() {
switchImageAndWait(true);
});
}
});
$(function() {
//calling every 20 millseconds
setInterval(function() {
changeLogo();
}, 200);
});
function changeLogo() {
//taking first active logo
var shownLogo = $(".client-logos-grid").find('.client-logo:not(.hidden)');
var shownLogo = $(".client-logos-grid").find('.client-logo:not(.hidden)');
shownLogo.fadeOut(200, function() {
shownLogo.addClass('hidden');
//check if its the last logo in the row
if (shownLogo.next('.client-logo').length > 0) { // not last
shownLogo.next('.client-logo').fadeIn(400, function() {
shownLogo.next('.client-logo').removeClass('hidden');
});
} else { // last
//move to first
$('.client-logo:first').fadeIn(400, function() {
$('.client-logo:first').removeClass('hidden');
});
}
});
}
.hidden {
display: none;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div class="client-logos-grid">
<img src="" alt="">A
<img src="" alt="">B
<img src="" alt="">C
<img src="" alt="">D
<img src="" alt="">E
<img src="" alt="">F
<img src="" alt="">G
<img src="" alt="">H
</div>
Are you looking for something like this?
i inspect their web and they use their custom js to animate the logo transition.
you can also do this by using simplefadeslideshow
<div id="slideshow">
<li><img src="images/4.jpg" width="640" height="480" border="0" alt="" /></li> <!-- This is the last image in the slideshow -->
<li><img src="images/3.jpg" width="640" height="480" border="0" alt="" /></li>
<li><img src="images/2.jpg" width="640" height="480" border="0" alt="" /></li>
<li><img src="images/1.jpg" width="640" height="480" border="0" alt="" /></li> <!-- This is the first image in the slideshow -->
</div>
and bind the plugin to the HTML structure you have created
jQuery(document).ready(function(){
jQuery('#slideshow').fadeSlideShow();
});
the demo web can be seen here hope this helps

Scale images & HTML5 videos to fit a row with an equal height

I have a bit of a problem with a gallery.
I'm trying to fit images & videos in a row and have them keep an equal height.
I could achieve that with the following code but only in the case of a row full of images. If I try to place a video, it doesn't work...
var videos = document.querySelector('.gallery-video');
$(".img-row").each(function () {
var row = $(this),
rowItems = row.find(".gallery-item"),
totalMarginSpace = (4 * (rowItems.length - 1)),
itemsWidthSum = 0,
diff,
rowItem,
rowItemWidth;
videos.addEventListener('loadeddata', function() {
rowItems.height(1000);
for(var i = 0 ; i < rowItems.length ; i++) {
rowItem = rowItems[i];
rowItemWidth = $(rowItem).outerWidth();
itemsWidthSum += rowItemWidth;
}
if(rowItems.length >= 3) {
diff = (row.width() - totalMarginSpace) / itemsWidthSum;
rowItems.height(999 * diff);
} else {
rowItems.height(250);
}
}, false);
});
Here's my HTML :
<section class="gallery-section">
<div class="img-row">
<video class="gallery-item gallery-video" autoplay loop muted="muted" preload="auto" >
<source src="" type="video/mp4">
</video>
<img class="gallery-item" src="" alt="" />
<img class="gallery-item" src="" alt="" />
<img class="gallery-item" src="" alt="" />
</div>
<div class="img-row">
<img class="gallery-item" src="" alt="" />
<img class="gallery-item" src="" alt="" />
<video class="gallery-item gallery-video" autoplay loop muted="muted" preload="auto" >
<source src="" type="video/mp4">
</video>
<img class="gallery-item" src="" alt="" />
</div>
<div class="img-row">
<img class="gallery-item margot" src="" alt="" />
<img class="gallery-item" src="" alt="" />
<img class="gallery-item" src="" alt="" />
<img class="gallery-item margot" src="" alt="" />
</div>
<div class="img-row">
<img class="gallery-item margot" src="" alt="" />
</div>
Any ideas on how to get my code to work ?
Thank you !
Code updated : I replaced item.width by item.offsetWidth (as width return nothing with videos).. It's a bit better but now the rows containing the videos are smaller than the one without.
Solution found ! Thanks for all your help but I really wanted to use JS to resolve my problem.
Ok so it did come from the videos because they were not completely loaded yet. So I added an eventlistener. I updated my code in case anyone wants to use it.
Try making a table
<table>
<tr>
<th>your imgs</th>
<th>your videos</th>
...
</tr>
</table>
then try to adjust the table with responsive CSS with this tutorial. I don't know if I understood your problem but I hope this helps.

How do I change image B's src to Image A's src when Image A is clicked with Javascript?

Goal: When image A is clicked that same image appears at the bottom of the page. Needs to work for more than one image.
When image A is clicked I need image B to now have the same src as image A.
Or to Generate a copy of the clicked image.
This should also be able to work for several pictures.
So for example if I clicked 5 images (Image A-01, A-02, A-03, A-04, A-05) on the screen....
At the bottom of the page there should be those 5 images
I've tried
HTML:
<img id="myImage" src="http://placehold.it/150">
<img id="new" src="http://placehold.it/200">
JS
$(function(){
$("#myImage").click(function() {
$("#new").attr("src","http://placehold.it/150")
});
});
Which works to replace one image but I need the same code to work for multiple image clicks.
Another proposal with an event listener.
var imgCount = 5,
i;
for (i = 1; i <= 5; i++) {
document.getElementById('img' + i).addEventListener('click', setImg('img' + i), false);
}
function setImg(id) {
return function () {
var img = document.createElement('img');
if (imgCount) {
imgCount--;
img.src = document.getElementById(id).src;
document.getElementById('footer').appendChild(img);
};
}
}
<img id="img1" src="http://lorempixel.com/200/100/city/1" />
<img id="img2" src="http://lorempixel.com/200/100/city/2" />
<img id="img3" src="http://lorempixel.com/200/100/city/3" />
<img id="img4" src="http://lorempixel.com/200/100/city/4" />
<img id="img5" src="http://lorempixel.com/200/100/city/5" />
<div id="footer"></div>
This will help you out
function changeSrc(id){
document.getElementById('footer').src = document.getElementById(id).src;
}
<img src="http://imgsv.imaging.nikon.com/lineup/lens/zoom/normalzoom/af-s_dx_18-140mmf_35-56g_ed_vr/img/sample/sample1_l.jpg" height="200" width="auto" id="img1" onclick="changeSrc(this.id)"/>
<img src="https://images-eu.ssl-images-amazon.com/images/G/02/uk-electronics/product_content/Nikon/ECS-NK1308141-B00ECGX8FM-2L-1024w683q85s10-BKEH_London_Paris__0316.jpg" height="200" width="auto" id="img2" class="image" onclick="changeSrc(this.id)"/>
<img src="" height="200" width="auto" id="footer" class="image" />
Try this:
<img src="https://randomuser.me/api/portraits/thumb/men/57.jpg" class="a">
<img src="https://randomuser.me/api/portraits/thumb/women/14.jpg" class="a">
<img src="https://randomuser.me/api/portraits/thumb/women/7.jpg" class="a">
<br>
<div id="sectionB">
<img src="http://placehold.it/48" class="b">
<img src="http://placehold.it/48" class="b">
<img src="http://placehold.it/48" class="b">
</div>
<br>
<button id="reset">Reset</button>
===
$(function() {
$('.a').click(function() {
var img = $(this).attr('src');
var index = $(this).index();
$('.b').eq(index).attr('src', img);
})
$('#reset').click(function(){
$('.b').attr('src', 'http://placehold.it/48');
})
})
DEMO: https://jsfiddle.net/j359yfor/

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