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.
And, of course, you'll need a good web server as well, if you're hunting for a web hosting company, you can click here to read reviews about the best web hosting out there! iPage Review
Requirements
You will need the following items and environment to run this script
- Web server with PHP support - XAMPP (mac, win and linux)
- jQuery
- history.js
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!
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.can you help me ?
1. Download and use new jQuery skript:
http://ajax.microsoft.com/ajax/jquery/jquery-1.4.4.min.js
2. Change this code lines in jQuery script:
---------------------------------------------------------
$(document).ready(function () {
to
$(window).ready(function () {
---------------------------------------------------------
$('a[href=' + document.location.hash + ']').addClass('selected');
to
$('a[href=' + window.location.hash + ']').addClass('selected');
---------------------------------------------------------
var data = 'page=' + document.location.hash.replace(/^.*#/, '');
to
var data = 'page=' + encodeURIComponent(window.location.hash);
---------------------------------------------------------
That's it!
Ajax loads now perfectly in IE and without this changes I get only that the URL is changing but the ajax pages doesn't won't to load...
:: cheers ::
I've used your technique on a website i am developping! It works fine on IE and FF but when i use safari or chrome i'm having some issues. Sometime i'll click on another page and the page will simply reload without changing to the clicked page:
http://deuxhuithuit.com/dev/melanieguay/
If anyone as experienced this problem or has a clue it woulf be greatly appreciated.
Thanks
// Live handler called.
alert("ajax content");
});
"using the same concept.
'; break; case '#page2' : $page = 'Portfolio
You can put"
Any answers to this one? Thanks
Firstly, thank you to the author for writing this. It has given me a good start into the world of AJAX. I did note some of the issues others were having, and so made some adjustments. Notably, I changed:
1. The history init and load calls have been tweaked. These now init and save correctly.
2. I removed the pageLoad function, as it was not needed after the history lib change
3. I have set it to load my home link in the menu on page load. Easy done.
4. Other minor tweaks, like using this rather than statically referencing an object on the DOM
Anyway, my next post has the code. I am happy to be contacted by email abbakiri at me dot com if you would like more info.
Cheers,
Joe
To anyone reading it, the posts are listed in reverse order, so check you have it the right way around before trying it!
Happy coding!
$(document).ready(function () {
$.history.init(function (hash){
//Check if url history value exists
if(hash == ''){
//Loads my home data on first load
getPage('home');
//set the home link class to selected
$('a[href=#home]').addClass('selected');
//Search for link with REL set to ajax
$('a[rel=ajax]').click(function () {
//fade out the content and bring up loader
$('#content').fadeOut('slow');
$('#loader').fadeIn('slow');
//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
$('li a').removeClass('selected');
//Used this as it works nicely in JQ
$(this).addClass('selected');
//run the ajax
getPage(hash);
//cancel the anchor tag behaviour
return false;
});
//set the hash for the getPage call
var hash = location.hash.replace(/^.*#/, '');
//I remove ALL selected classes
//This has to change if you have other links with selected classes
$('li a').removeClass('selected');
//Fading out the content and in the loader
$('#content').fadeOut('fast');
$('#loader').fadeIn('fast');
//getPage from history
getPage(hash);
//highlight the selected link
$('a[href=' + location.hash + ']').addClass('selected');
}
});
});
function getPage(hash) {
//generate the parameter for the php script
var data = 'page=' + hash; //'page=' + document.location.hash.replace(/^.*#/, '');
$.ajax({
url: "core/pageLoader.php",
type: "GET",
data: data,
cache: false,
success: function (html) {
//hide the progress bar
$('#loader').fadeOut('slow');
//for some reason, the ajax call used to bring up the hidden div
//then hide it, then fade it in. Looked bad!
//So, I hide it again here, then we load the data in, then we
//fade it back up. Seems to work nicely now.
$('#content').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');
}
});
}
i'm iranian.....