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jQuery Photo Slide Show with Slick Caption Tutorial Revisited

Written by Kevin Liew on 16 Dec 2009
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488 comments

Introduction

If you have been reading my website from the start you would have read this tutorial:

Simple jQuery Image Slide Show with Semi Transparent Caption

It's a very famous post because it has been showcased in several major web design blogs so many times and I received a lot of traffic from it. Thanks guys. I get a lot of comment and as I replied to those comments and do some quick fixes, I realized that this script has a caption bug and inefficient and not up to standard (oh well, that's the time when I was start picking up jQuery :)), so I have decided to do revisit to solve all those problems discovered by readers. I rewrote the html structure and modify the script.

Mission Objectives:

  • Restructure the HTML, more semantic
  • Fix the caption bug, it displays the next caption too fast
  • W3C standard compliant, using appropriate attribute to store title and description
  • Cross Browser - Chrome, Safari, IE6, 7, 8 and Firefox.

However, one thing though, it needs javascript, if your browser is javascript disabled, sorry, there is no graceful degradation for this script, it will just display the first item.

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1. HTML

Yes, I'm using list this time :) This is how it should have been afterall. No more REL attribute, we wil be using TITLE Attribute to store the heading and ALT attribute to store the description. For the caption elements, it will be added using jQuery. So, this is it - a clean and simple HTML code.

<ul class="slideshow">
	<li class="show"><a href="#"><img src="images/s1.gif" width="450" height="200" title="Slide 1" alt="Short Description"/></a></li>
	<li><a href="#"><img src="images/s2.gif" width="450" height="200" title="Slide 2" alt="Short Description"/></a></li>
	<li><a href="#"><img src="images/s3.gif" width="450" height="200" title="Slide 3" alt="Short Description"/></a></li>
</ul>

2. CSS

CSS code is rewritten completely. I guarantee it's cross browser compliant. They all look identical and it works great :) I did learn a lot of CSS technique through this blog. We all can improve our skills through tips, tricks, trials and errors. Read these posts to learn more about CSS:

body {
	font-family:arial;	
	font-size:12px;
}

ul.slideshow {
	list-style:none;
	width:450px;
	height:200px;
	overflow:hidden;
	position:relative;
	margin:0;
	padding:0;
	
}	

ul.slideshow li {
	position:absolute;
	left:0;
	right:0;
}

ul.slideshow li.show {
	z-index:500;	
}

ul img {
	border:none;	
}

#slideshow-caption {
	width:450px;
	height:70px;
	position:absolute;
	bottom:0;
	left:0;	
	color:#fff;
	background:#000;
	z-index:500;
}

#slideshow-caption .slideshow-caption-container {
	padding:5px 10px;	
	z-index:1000;	
}

#slideshow-caption h3 {
	margin:0;
	padding:0;	
	font-size:14px;
}

#slideshow-caption p {
	margin:5px 0 0 0;
	padding:0;
}

3. Javascript

We will going to use call back function to display caption. This will solve the "Caption Is Appearing Before The Next Slide Syndrome" :). Not too much of changes in javascript but I do added a feature though. On mouse over the slide will pause, and resume it back on mouse out. I think it's a good touch.

$(document).ready(function() {		
	
	//Execute the slideShow, set 4 seconds for each images
	slideShow(2000);

});

function slideShow(speed) {


	//append a LI item to the UL list for displaying caption
	$('ul.slideshow').append('
  •  
'); //Set the opacity of all images to 0 $('ul.slideshow li').css({opacity: 0.0}); //Get the first image and display it (set it to full opacity) $('ul.slideshow li:first').css({opacity: 1.0}).addClass('show'); //Get the caption of the first image from REL attribute and display it $('#slideshow-caption h3').html($('ul.slideshow li.show').find('img').attr('title')); $('#slideshow-caption p').html($('ul.slideshow li.show').find('img').attr('alt')); //Display the caption $('#slideshow-caption').css({opacity: 0.7, bottom:0}); //Call the gallery function to run the slideshow var timer = setInterval('gallery()',speed); //pause the slideshow on mouse over $('ul.slideshow').hover( function () { clearInterval(timer); }, function () { timer = setInterval('gallery()',speed); } ); } function gallery() { //if no IMGs have the show class, grab the first image var current = ($('ul.slideshow li.show')? $('ul.slideshow li.show') : $('#ul.slideshow li:first')); //trying to avoid speed issue if(current.queue('fx').length == 0) { //Get next image, if it reached the end of the slideshow, rotate it back to the first image var next = ((current.next().length) ? ((current.next().attr('id') == 'slideshow-caption')? $('ul.slideshow li:first') :current.next()) : $('ul.slideshow li:first')); //Get next image caption var title = next.find('img').attr('title'); var desc = next.find('img').attr('alt'); //Set the fade in effect for the next image, show class has higher z-index next.css({opacity: 0.0}).addClass('show').animate({opacity: 1.0}, 1000); //Hide the caption first, and then set and display the caption $('#slideshow-caption').slideToggle(300, function () { $('#slideshow-caption h3').html(title); $('#slideshow-caption p').html(desc); $('#slideshow-caption').slideToggle(500); }); //Hide the current image current.animate({opacity: 0.0}, 1000).removeClass('show'); } }

Updates

2010-09-10: Thanks to Rezzie who nailed the IE8 issue! :)

Updated the article and scripts, the link issue is fixed. :) Sorry for the delay.

Speed Issue

This is one of the issue that has been haunted me for a while, but thanks to Sam, one of our reader, he pointed out this would solve the issue, but with mixed result in IE.

Sam's solution, you need to add this:

$(window).focus(function () {
	timer = setInterval('gallery()', speed); 
});
$(window).blur(function () {
	clearInterval(timer);
});

James Burnett's solution, you modify the gallery function():

function gallery() {
	var current = ($('ul.slideshow li.show')? $('ul.slideshow li.show') : $('#ul.slideshow li:first'));

	if(current.queue('fx').length == 0) {
		
		// grab next image and animate code in here
		......
		......
		......
		
	}
}

Also, did some research, found the reason why it's doing it: From jQuery Animate Documentation: Because of the nature of requestAnimationFrame(), you should never queue animations using a setInterval or setTimeout loop. In order to preserve CPU resources, browsers that support requestAnimationFrame will not update animations when the window/tab is not displayed. If you continue to queue animations via setInterval or setTimeout while animation is paused, all of the queued animations will begin playing when the window/tab regains focus. To avoid this potential problem, use the callback of your last animation in the loop, or append a function to the elements .queue() to set the timeout to start the next animation.

Sorry guys, I don't have time to put all these together. Please let me know it works.

Randomize Slides

Simple yet effective solution from another reader - Blastos

Before the ending of function slideShow(), put this in:

//Generate a random number
var randNum = Math.floor(Math.random() * $('ul.slideshow li').length);

//Randomly pick up a slide
$('ul.slideshow li:eq('+randNum+')').addClass('show');

Caption doesn't appear for the first slide

I think it has to be the ommitted A tag for some users. Ammended the script, it should be fixed now.

Conclusion

I have made a lot of tutorials, and I think it's good to do a revisit to make it more efficient and solve some of the annoying bugs instead of quick fixes. So, yea, from now on, I will check my previous tutorials and rewrite them. :)

Like this tutorials? You can express your gratitude by visiting my sponsors on the sidebar, bookmark it and help me to spread this tutorial to our friends! :) Thanks!

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488 comments
ericjogja 7 years ago
thank you for sharing this valuable tutorial,
I am a beginner from Indonesia who started learning to modify the blog
regard
Reply
Clarke Isackson 7 years ago
Here is your fix. Change the DIV class= to DIV id=. Also, you should not capitalize the DIV, LI or UL.....

//append a LI item to the UL list for displaying caption
$(\'ul.slideshow\').append(\'<LI id=slideshow-caption class=caption><DIV id=slideshow-caption-container><H3></H3><P></P></DIV></LI>\');
Reply
Clarke Isackson 7 years ago
Sorry I should have explained that the current jQuery had a very minor error that prevented the next appends from occuring with the h3 and p title and description, so your application kept cycling on the FIRST title and descriptive values. I hope the above post helps anyone wanting to put this into action right away. It is very nice.
Reply
kevin Admin 7 years ago
Hi Clarke, hmmm, I look at the demo again, and I don\'t have the problem you mentioned to me. Each slide has the correct title and descriptive text.
Reply
Clarke Isackson 7 years ago
Yes, I am running VIsta pro and the latest IE 8. The app will not run without the correction (on my system). I\'ll try it on some others later, but it was worth noting.
Reply
Clarke Isackson 7 years ago
Tried it with FireFox on Vista and it works. Minor situration and yet another example fo IE inconsistancies.

Again. this was a very neat approach. Thanks for the demo.
Reply
ericjogja 7 years ago
several times I\'ve tried (I am using windows xp and mozilla firefox).
This warning appears
\"when I template is invalid because the tag \'div\' appears in the tag \'head\'.\" Regard
Reply
Slobodan Kustrimovic 7 years ago
I use Firefox, Chrome and IE Tester on Windows Seven. :)

Little misunderstanding, i thought you are using IE8 and Vista as primary browser and OS for development. :) (don\'t ask me why, i dunno)

I do test in IE, FF and Chrome when developing.
Reply
Slobodan Kustrimovic 7 years ago
@Clarke you are the first developer i saw that uses IE8 (+ the crappiest OS) :)
Reply
Alyssa 7 years ago
Is there a way to get this to start on a click instead of on load? I tried changing
$(document).ready(function() {
//Execute the slideShow, set 4 seconds for each images
slideShow(4000);

});
to
$(document).ready(function() {
$(\"button\").click(function(){
//Execute the slideShow, set 4 seconds for each images
slideShow(4000);
};
});

with <button type=\"button\">Click to start</button> in the body, but my slideshow will just come up on the last slide and do nothing.
Reply
Alyssa 7 years ago
Scratch that, I figured it out :)
Reply
Alyssa 7 years ago
Okay, so I got my button to work, but now the timings are screwy. It will go really fast through some and normal through others. Is there a way to make it change on click instead of by a timer?
Reply
Clarke Isackson 7 years ago
This is the first jQuery demo that had a problem in any of my software enfironments and I was silly enough to share the situation.

TV, what browser do you use?

I would hope developers use more than one browser to test their products. As I mentioned, I am using several different computers and several browsers. I am more concerned about making jQuery work than exaggerate the positive or negative quality of a specific browser.
Reply