A Simple AJAX Driven Website with jQuery + PHP

Written by Kevin Liew on 08 Jul 2009
402,268 Views • Tutorials

Introduction

AJAX is abbrieviated from Asynchrounous javascript and XML. It's not a new technology, but the implementation of a group of technologies to achieve a seamless interaction between client and server.

Typically, xhtml and css to present the information, javascript is used to handle user interactions, and a server side language to perform the users' requests (and normally return data in XML format, in this tutorial, we won't do that), and it all is happening in the background using the Javascript XMLHttpRequest. Javascript plays a main role tie all these technologies together and create the asynchronous interaction between client ans server.

AHAH (Asynchrounous HTML and HTTP) is a subset of AJAX which is another technique, Inspite of retreiving XML, AHAH is retreiving HTML content. Both of them are basically the same, the only difference is the content it returns. Generally, most people will simply call it AJAX, but technically, we should call it AHAH. In this tutorial, AHAH is used.

The Good, Bad and Solutions

The Goodies:

  • Reduce connections and bandwidth to the server, images, scripts, stylesheets only need to be downloaded once
  • Reduce loading timew. User doesnt have to load pages again and again, it all happens in a same page!
  • Increase responsiveness and end user experiences.

The Badies:

  • Browser Back button. AJAX web pages cannot connect with browser history engine. If you clicked on back button, you can't navigate those AJAX content.
  • Bookmark will not work on AJAX webpages. Due to the dynamic content, you might bookmark the homepage instead of the desired page.
  • Javascript is needed. To run AJAX based website, your browser need to have javascript enabled.

The Solutions:

AJAX is not a perfect technology, but some of the limitations can be overcame with some simple solutions. I found this very userful plugin called jquery.history.js. It solves Browser Back Button. For the bookmark problem, we can solve it by appending a hash value in the end of the url.

For the last one - javascript, we are going to ignore it. It can be done but I want to keep this tutorial simple.

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Requirements

You will need the following items and environment to run this script

1. HTML

I will provide two versions of HTML code. The first one is the most basic elements you will need to get it working. And the last one is the one I created with some design

Simplified versions
<ul>
	<li><a href="#page1" rel="ajax">Home</a></li> 
	<li><a href="#page2" rel="ajax">Portfolio</a></li> 
	<li><a href="#page3" rel="ajax">About</a></li>
	<li><a href="#page4" rel="ajax">Contact</a></li>
</ul>

<div class="loading"></div>

<div id="content">
<!-- Ajax Content -->
</div>
		

2. CSS

This is really really simple, just have to keep the loading and content hidden

#loading {
	background: url(images/load.gif) no-repeat;
	display:none;
}
			
#content {
	font-family:arial;
	font-size:11px;
	display:none;
}	

3. Javascript

I have added comments in every single lines of the code.

	
$(document).ready(function () {
	
	//Check if url hash value exists (for bookmark)
	$.history.init(pageload);	
	    
	//highlight the selected link
	$('a[href=' + document.location.hash + ']').addClass('selected');
	
	//Seearch for link with REL set to ajax
	$('a[rel=ajax]').click(function () {
		
		//grab the full url
		var hash = this.href;
		
		//remove the # value
		hash = hash.replace(/^.*#/, '');
		
		//for back button
	 	$.history.load(hash);	
	 	
	 	//clear the selected class and add the class class to the selected link
	 	$('a[rel=ajax]').removeClass('selected');
	 	$(this).addClass('selected');
	 	
	 	//hide the content and show the progress bar
	 	$('#content').hide();
	 	$('#loading').show();
	 	
	 	//run the ajax
		getPage();
	
		//cancel the anchor tag behaviour
		return false;
	});	
});
	

function pageload(hash) {
	//if hash value exists, run the ajax
	if (hash) getPage();    
}
		
function getPage() {
	
	//generate the parameter for the php script
	var data = 'page=' + document.location.hash.replace(/^.*#/, '');
	$.ajax({
		url: "loader.php",	
		type: "GET",		
		data: data,		
		cache: false,
		success: function (html) {	
		
			//hide the progress bar
			$('#loading').hide();	
			
			//add the content retrieved from ajax and put it in the #content div
			$('#content').html(html);
			
			//display the body with fadeIn transition
			$('#content').fadeIn('slow');		
		}		
	});
}

4. PHP

We will not go further on PHP code, this time, I'm using a basic switch to grab the content. The content for the page is being assigned to a variable called "page". And the last line, output the content.

To debug the php script, you can access it by passing data into it, for example:

http://www.someurl.com/loader.php?page=page1

It should display the content for page1. If you know about php and database, you can store the content in the database and retrieve it. Make a simple form to edit the content and BANG... you got yourself a customized content management system.

	

//Get the page parameter from the url
switch($_GET['page'])  {
	case 'page1' : $page = 'Page 1'; 
					break;
	case 'page2' : $page = 'Page 2'; 
					break;
	case 'page3' : $page = 'Page 3'; 
					break;
	case 'page4' : $page = 'Page 4'; 
					break;
}
echo $page;

Conclusion

That's it. Make sure you check out the demo and download the source code and play with it. If you have created your own, feel free to drop your link in the comment section to show off! : )

Last but not least, I need your support :) If you like this article, please help me to promote it by adding this post to your bookmark. Or you can subscribe to my RSS for more jQuery tutorial and design inspiration posts! Thanks!

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188 comments
Web010 16 years ago
Great tutorial. :) Keep it up.
Reply
FireDart 16 years ago
Very cool, thanks for sharing.
Reply
endorphine 16 years ago
You aren't suppose to rely that much on ajax, it is bad for SEO.
Reply
WebDevVote.com 16 years ago
You are voted!
Track back from WebDevVote.com
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e11world 16 years ago
Very nice! i'd like to use this for one of my future works
Reply
perpetum 16 years ago
really nice tutorial. keep work for others :]
Reply
asdf 16 years ago
asdfasdf
Reply
dlv 16 years ago
really usefull, thanks for sahre
i love this site, always good resources!
Reply
daniel 16 years ago
hi Great stuff. does it work with 1.2.6? I need it because of an other script i wrote long ago ;-)
Reply
Angel Rodriguez 16 years ago
There is a Problem with the "Reload" of Internet Explorer.... Probe it !!!
Reply
Michelle 16 years ago
I'm curious if you think you could get this working with select drop-downs that automatically load content. I've got it working with Firefox, but IE doesn't seem to like it.
Reply
mike 16 years ago
How do you show a default content before a link is clicked?
Reply
kevin Admin 16 years ago
@mike: hey, good point! this is how you do it:

if (document.location.hash=='') var data = 'page=' + encodeURIComponent('#page1');
else var data = 'page=' + encodeURIComponent(document.location.hash);

replace the 3rd line of getPage() function with that, you can choose which page you wanna load as well.

@ricardo: Hi there, glad to hear that it helped you a lot. Yes, firstly, you have to modify this line, separate different data with ampersand &s symbol:

var data = 'page=' + hash + '&newvar=data'

in php side, if you want to get the data, you need to use this:

$_GET['newvar']

the name must be the same with the one you pass in the url.
Reply