Create an Attractive Before and After Photo Effect with jQuery

Written by Kevin Liew on 24 Jan 2011
105,909 Views • Tutorials

Introduction

13 Jan 2011, Australia suffered a catastrophic flood disaster, almost 75% of Queensland was affected. Inland Tsunami in Toowoomba, evacuation of Brisbane city, it was a total chaos in the entire state. Sudden flood which lead to torrential and ferocious flood destroyed homes and killed many. It will take 2 years to recover. If you wish to donate, please visit Queensland Government State Website.

The reason I bought it up because I got this inspiration from this website - Queensland Floods - Before After.

Well, it is saddening to see all the damages the flood did. In the other hand, I also notice the way it presents the before and after photos. It's just so intuitive and simple. So, I have decided to build something similar but with a few of enhancements. I'm going to show you how to build it and how to convert it to plugins. Tested on IE6, 7, 8, Firefox, Chrome and Safari. 

You may want to check out the demo now:

HTML

I keep the HTML really simple, just a div with 2 images in it. Things you need to know:

  • value in ALT attribute will be used as caption
  • width and height of the first image will be used for calculation, therefore, it's mandatory to have it defined

This is what you need to use it:

<div class="beforeafter">
	<img data-src="image-1.jpg" alt="Before" width="500" height="280">
        <img data-src="image-2.jpg" alt="After" width="500" height="280">																																							
</div>

However, the content in the div will be totally revamped once it's processed by javascript. This is the real structure:

<div class="beforeafter">
	<div class="ba-mask"></div>
	<div class="ba-bg"></div>
	<div class="ba-caption"></div>
	<img data-src="image-1.jpg" alt="Before" width="500" height="280">
	<img data-src="image-2.jpg" alt="After" width="500" height="280">		
</div>
<div class="beforeafter">
	<img data-src="image-1.jpg" alt="Before" width="500" height="280">
        <img data-src="image-2.jpg" alt="After" width="500" height="280">																																							
</div>

CSS

CSS isn't that complicated as well. I have illustrated how this script going to work which will make it easy to understand

Queness before and after jQuery Plugin Tutorial
#container {width:500px; margin:0 auto;}
		
/* width and height for the block */
.beforeafter {width:500px; height:280px;}		
		
		
/* The following is the mandatory styling for the plugins */
	
.ba-mask {	/* first image */	
	position:absolute; 
	top:0; 
	left:0; 
	z-index:100; 
	border-right:4px solid #000; 
	overflow:hidden; 
	box-shadow: 3px 5px 5px rgba(0, 0, 0, 0.6);
	box-shadow: 5px 5px 10px rgba(0, 0, 0, 0.6); 
	-webkit-box-shadow: 5px 5px 7px rgba(0, 0, 0, 0.6);  
	-moz-box-shadow: 5px 0 7px rgba(0, 0, 0, 0.6);
}

.ba-bg {	/* second image */
	position:absolute; 
	top:0; 
	left:0; 
	z-index:0;
}

.ba-caption {	/* caption	*/
			
	/* mandatory */
	position:absolute; 
	bottom:10px; 
	left:10px; 
	z-index:120;	
			 
	/* customizable styling */
	background:#000; 
	color:#fff; 
	text-align:center;
	padding:5px; 
	font-size:12px; 
	font-family:arial; 
	filter:alpha(opacity=80);-moz-opacity:0.8;-khtml-opacity: 0.8;opacity: 0.8; 
	-webkit-border-radius:5px; -moz-border-radius:5px; border-radius:5px; 			
}

Javascript

Alright, some intensive stuff going on over here. The length of the script is pretty long, it's because I'm trying to make this script as flexible as possible and also make the HTML and CSS as simple as possible. You see, once we have the flexibility and simplicity lead to lengthly and complicated code.

I have written a comment to walk you through the whole javascript.

$(document).ready(function() {
	
	// Some options for customization
	var leftgap = 10;		/* gap on the left */
	var rightgap = 10;		/* gap on the right */
	var defaultgap = 50;	/* the intro gap */
	var caption = true;		/* toggle caption */
	var reveal = 0.5;		/* define 0 - 1 far does it goes to reveal the second caption */
		
	// find each of the .beforeafter
	$('.beforeafter').each(function () {
		
		// set current selected item to variable
		var i = $(this);			
		// get the source of the first image and second image using eq(index)
		var img_mask = i.children('img:eq(0)').attr('src');
		var img_bg = i.children('img:eq(1)').attr('src');
			
		// get the caption for the first image as default caption
		var img_cap_one = i.children('img:eq(0)').attr('alt');
			
		// get the dimension of the first image, assuming second image has the same dimension
		var width = i.children('img:eq(0)').width();
		var height = i.children('img:eq(0)').height();
			
		// hide the images, not removing it because we will need it later
		i.find('img').hide();		
			
		// set some css attribute to current item for graceful degradation if javascript support is off
		i.css({'overflow': 'hidden', 'position': 'relative'});
			
		// append additional html element
		i.append('</pre><div class="ba-mask"></div><pre class="js">');
		i.append('</pre><div class="ba-bg"></div><pre class="js">');			
		i.append('</pre><div class="ba-caption">' + img_cap_one + '</div><pre class="js">');						
			
		// set the dimension of appended html element
		i.children('.ba-mask, .ba-bg').width(width);
		i.children('.ba-mask, .ba-bg').height(height);
			
		// set the images as background for ba-mask and ba-bg
		i.children('.ba-mask').css('backgroundImage','url(' + img_mask + ')');
		i.children('.ba-bg').css('backgroundImage','url(' + img_bg + ')');				

		// animate to reveal the background image
		i.children('.ba-mask').animate({'width':width - defaultgap}, 1000);		

		// if caption is true, then display it, otherwise, hide it
		if (caption) i.children('.caption').show();
		else i.children('.ba-caption').hide();
			
	}).mousemove(function (e) {

		// set current selected item to variable
		var i = $(this);
			
		// get the position of the image
		pos_img = i.offset()['left'];
			
		// get the position of the mouse pointer
		pos_mouse = e.pageX;		
			
		// calculate the difference between the image and cursor
		// the difference will the width of the mask image
		new_width = pos_mouse - pos_img;
		img_width = i.width();
			
		// get the captions for first and second images
		img_cap_one = i.children('img:eq(0)').attr('alt');
		img_cap_two = i.children('img:eq(1)').attr('alt');
			
		/*
		// for debugging purposes
		$('#debug').html("X Axis : " + e.pageX + " | Y Axis " + e.pageY);
		$('#debug2').html(i.position()['left']);
		$('#debug3').html(new_width);
		*/
			
		// make sure it reveal the image and left some gaps on left and right
		// it depends on the value of leftgap and rightgap
		if (new_width &gt; leftgap &amp;&amp; new_width &lt; (img_width - rightgap)) {			
			i.children('.ba-mask').width(new_width);
		}	

		// toggle between captions.
		// it uses the reveal variable to calculate
		// eg, display caption two once the image is 50% (0.5) revealed.
		if (new_width &lt; (img_width * reveal)) {			
			i.children('.ba-caption').html(img_cap_two);
		} else {
			i.children('.ba-caption').html(img_cap_one);			
		}	 								
					
	});
	
 });
 

Convert to Plugin

First of all, what we need to know is the structure of a plugin. I shared about this long time ago, so if you want to know more about it, visit this post - A Really Simple jQuery Plugin Tutorial. Over here I will just paste the structure we going to use in this tutorial:

//You need an anonymous function to wrap around your function to avoid conflict
(function($){
 
    //Attach this new method to jQuery
    $.fn.extend({
         
        //This is where you write your plugin's name
        pluginname: function() {
 
            //Iterate over the current set of matched elements
            return this.each(function() {
             
                //code to be inserted here
             
            });
        }
    });
     
//pass jQuery to the function,
//So that we will able to use any valid Javascript variable name
//to replace "$" SIGN. But, we'll stick to $ (I like dollar sign :) )      
})(jQuery);

Alright, the next thing we need to do, mix the plugin stucture with the before after script, and this is the final result:

(function($){
   $.fn.extend({
		//plugin name - qbeforeafter
		qbeforeafter: function(options) {
 
			var defaults = {
				defaultgap: 50,            
				leftgap: 10,
				rightgap: 10,
				caption: false,
				reveal: 0.5
			};
             
			var options = $.extend(defaults, options);
         
			return this.each(function() {

            var o = options;
            var i = $(this);
			var img_mask = i.children('img:eq(0)').attr('src');
			var img_bg = i.children('img:eq(1)').attr('src');
			var img_cap_one = i.children('img:eq(0)').attr('alt');
			
			var width = i.children('img:eq(0)').width();
			var height = i.children('img:eq(0)').height();
				
			i.children('img').hide();		
				
			i.css({'overflow': 'hidden', 'position': 'relative'});
			i.append('</pre><div class="ba-mask"></div><pre class="js">');
			i.append('</pre><div class="ba-bg"></div><pre class="js">');			
			i.append('</pre><div class="ba-caption">' + img_cap_one + '</div><pre class="js">');
				
			i.children('.ba-mask, .ba-bg').width(width);
			i.children('.ba-mask, .ba-bg').height(height);
			i.children('.ba-mask').animate({'width':width - o.defaultgap}, 1000);
			
			i.children('.ba-mask').css('backgroundImage','url(' + img_mask + ')');
			i.children('.ba-bg').css('backgroundImage','url(' + img_bg + ')');	

			if (o.caption) i.children('.ba-caption').show();

            }).mousemove(function (e) {

				var o = options;
				var i = $(this);
				
				pos_img = i.offset()['left'];
				pos_mouse = e.pageX;		
				new_width = pos_mouse - pos_img;
				img_width = i.width();
				img_cap_one = i.children('img:eq(0)').attr('alt');
				img_cap_two = i.children('img:eq(1)').attr('alt');				

				if (new_width &gt; o.leftgap &amp;&amp; new_width &lt; (img_width - o.rightgap)) {			
					i.children('.ba-mask').width(new_width);
				}
				
				if (new_width &lt; (img_width * o.reveal)) {			
					i.children('.ba-caption').html(img_cap_two);
				} else {
					i.children('.ba-caption').html(img_cap_one);			
				}					
			
			});
        }
   });
})(jQuery);	

If we compared it to the non-plugin script, the major difference is how we convert the customizable setting (defaultgap, leftgap, rightgap, caption and reveal) to plugins. That's it, pretty straight forward, just copy and paste and slight modification

How to use Queness' beforeafter plugin

The usage is really simple, this is how you call the plugin:

	
$(function () {
	$('.large').qbeforeafter({defaultgap:50, leftgap:0, rightgap:10, caption: true, reveal: 0.5});
	$('.small').qbeforeafter({defaultgap:20, leftgap:5, rightgap:10, caption: false});
});

Finally...

That's it, a tutorial after a long time. I hope you guys will like it. If you have any questions, suggestion or comment, drop me a message below. Also, help me to spread this post :) Thanks.

Demo 1Demo 2Download
Join the discussion

Comments will be moderated and rel="nofollow" will be added to all links. You can wrap your coding with [code][/code] to make use of built-in syntax highlighter.

53 comments
Morten 9 years ago
being a prototype.js user - I took your javascript and rewrote it to using protype - hope you don't mind. Still some work pending, but it works... it can be found at http://sickel.net/blogg/?p=1091
Reply
Kevin Liew Admin 9 years ago
Haha Morten, that's awesome! Prototype is the first javascript framework i learn! But I didn't dig deep enough. Good work.
Reply
Mahendra 9 years ago
Thanks Kevin. Gr8 plugin
Reply
Esther 9 years ago
This plugin is perfect for my client who wants to show "before" and "after" photos of his hair extensions models. However, I'm having trouble integrating this into a slideshow (like Cycle or Awkward), and was wondering if this is possible.
Reply
Kevin Liew Admin 9 years ago
Hi Esther, I haven't tried that before but it seems to be a pretty complicated solution you got there.
Reply
dr amir 8 years ago
first of all ..really great work ..the result is outstanding ..i've tried the catchmy script and although the bar is a bit fancier ..the scripting it self has nothing to compare to yours ..neat and effective .
i'm including it to a dental gallery , it will be awesome ..therefore and since i'm just a dentist with tiny skills in webdesign i would like to ask u just two tiny questions if i may:
1 is is possible to include a shadow or frame effect (pure css and html) on the pics without affecting the code .
2 is is possible to include the div in a webpage already build with another css ? or it would be easier to put the whole presentation in a popup if i can center the effet so it comes in the exact middle of the popup window ?
sorry for taking so long of your reading time ..it's just that i'm impressed :)

NB: u own me a free teeth cleaning if u even come to tunisia ;)
Reply
Kevin Liew Admin 8 years ago
Hi Dr Amir, thanks for your kind words :)
1. it's possible, for border or shadow, you need to do this to this css class:

.beforeafter {
border:5px solid #666;
box-shadow:0 0 5px rgba(0,0,0,0.8);
}

2. you can mix this script with other html elements, it shouldn't conflict with the layout. Not so sure about popup, you might get something like fancybox then display this before and after script in an iframe.
Reply
Ina 8 years ago
Exactly what I was looking for......great job!
Best regards,
Athens, Greece
Reply
Mirco Brandes 8 years ago
Hello Kevin,
i try to use your script, but i have a big problem.
If i load the site the first time, the effekt is not visible / does not work.
If i refresh / reload the site everything ist okay.

Do you have an idea, how i can solve this problem.

If you need a link or something else please send me a message.

Thanks
Mirco
Reply
Josh 8 years ago
Mirco,

I'm having the same problem with the before/after only working on a second load of each page. Did you ever figure this out? Would love to know what's going on. Thanks.
Reply
June 8 years ago
Hi
Is there an "easy" to change the code, that you don't have to drag from left to right, but from top to bottom?
Regards
J
Reply
Kevin Liew Admin 8 years ago
hmm, top to bottom will take some time to fiddling around.. I made a quick one, behave a lil different.

http://www.queness.com/resources/html/beforeafter/index_top.html

Reply
Levi 8 years ago
This is really awesome, good work. Is there any way I could have it in some sort of carousel? So I could click next and go to another before and after picture?

Thanks!
Reply
Kevin Liew Admin 8 years ago
hmm, tough request but you can try to put this script inside a carousel.... i doubt it will work though :p
Reply
marti 8 years ago
Hey! Is that plugin under any license?
Thanks!
Reply
Kevin Liew Admin 8 years ago
open source, you can use it and mod it.
Reply
MarkL 8 years ago
Hi there. Great plugin. One suggestion: make it "responsive". Right now removing width/height breaks the code. I'm trying to integrate it with my design based on Twitter bootstrap and resizing the window browser just messes things up before of the hardcoded width/height.

Cheers.
Reply
uzi 7 years ago
Yeah, this is real problem. I need this plugin but it have to work responsive
Reply
Regi 6 years ago
Not perfect, but a solution for the responsive need is to use different sizes of this code for different situations, such as: small screen, desktop screen, touch screen. This way, it will not perfect fulfill all screens, but it can match some standards screen sizes in the market. At www.csstemplateheaven.com I found in the past a free template called css creative-studios template that has this screens sizes solution code.
Reply
Flobs 8 years ago
Hi, I love the nice effect of the before and after photo but I was wondering if it also works on blogger? I tried to use it but I failed all the time. I'm quite a novide in programming stuff. Thank you for the awesome tutorial and sharing your work!
Reply
Agrest123 8 years ago
Hi.
Awsome plugin. I do a page about a medieval town. I need implement this plugin in my homepage buid on a joomla 1.5. I read a tutorial and I don't know how could I this function on my page. Who wants explain me how can I do this? This plugin allows me show an old and present pictures on my page.
Sorry for my english. I'm from Poland
Thanks
Reply
Maged 8 years ago
as mentioned in my previous post i usually use Flash, so i really miss the % size feature ..is there any chance that this script makes the photos dynamic i.e. set pictures size as a % of screen size width and height ?? as the constant Size interfere somewhat with a full dynamic sized website .
Reply
Kevin Liew Admin 8 years ago
I'm guessing you're talking about responsive. Unfortunately, it can't do it.
Reply
cugreen 7 years ago
Nice plugin. Thanks. I noticed I got image flickering if triggering mousemove before the initial animation finished.

I found putting a stop in fixed the issue. Like this.

i.children('.ba-mask').stop().width(new_width);
             
Reply