Ajax Examples
There are a few AJAX demos and examples on the web right now. While these are invaluable to learning AJAX, some people need a bit more information than just a raw piece of code. In todays environment there are many ways to learn AJAX including, books, classes, conferences, workshops and tutorials. Of these the only one that is free and accessible to everyone are web-based tutorials. The following is a list of what I consider the be the best and most helpful AJAX tutorials that I've found over the past year.
The Ajax alternate
Techniques
The first alternate Ajax technique is dynamic script loading. The concept is simple: create a new <script/> element and assign a JavaScript file to its src attribute to load JavaScript that isn't initially written into the page. The beginnings of this technique could be seen way back when Internet Explorer 4.0 and Netscape Navigator 4.0 ruled the web browser market. At that time, developers learned that they could use the document.write() method to write out a <script/> tag. The caveat was that this had to be done before the page was completely loaded. With the advent of the DOM, the concept could be taken to a completely new level.
Ajax and XMLHttp Request from webPasties
The XMLHttpRequest object is a handy dandy JavaScript object that offers a convenient way for webpages to get information from servers without refreshing themselves.
The benefit to end users is that they don't have to type as much and they don't have to wait as long. For example, having the user's city and state show up in a webpage automatically after the ZIP code has been typed in is a big time saver.
Although the XMLHttpRequest object might sound complex and different from any other JavaScript object you have ever used, it really isn't. A good way to think of the XMLHttpRequest object is as you would think of the JavaScript Image object. As we know, with the Image object you can dynamically specify a new URL for the image source without reloading the page. Similarly with the XMLHttpRequest object, you can dynamically specify a URL to get some server data without reloading the page.
The Ajax Make request with asynchronous
JavaScript
Most Web applications use a request/response model that gets an entire HTML page from the server. The result is a back-and-forth that usually involves clicking a button, waiting for the server, clicking another button, and then waiting some more. With Ajax and the XMLHttpRequest object, you can use a request/response model that never leaves users waiting for a server to respond. In this article, Brett McLaughlin shows you how to create XMLHttpRequest instances in a cross-browser way, construct and send requests, and respond to the server.
First, take this last bit of overview before you dive into code -- make sure you're crystal clear on this idea of the Web 2.0. When you hear the term Web 2.0, you should first ask, "What's Web 1.0?" Although you'll rarely hear Web 1.0, it is meant to refer to the traditional Web where you have a very distinct request and response model. For example, go to Amazon.com and click a button or enter a search term. A request is made to a server and then a response comes back to your browser.
The
Advanced requests and responses in Ajax
In the last article in this series, I provided a solid introduction to the XMLHttpRequest object, the centerpiece of an Ajax application that handles requests to a server-side application or script, and also deals with return data from that server-side component. Every Ajax application uses the XMLHttpRequest object, so you'll want to be intimately familiar with it to make your Ajax applications perform and perform well.
In this article, I move beyond the basics in the last article and concentrate on more detail about three key parts of this request object:
* The HTTP ready state
* The HTTP status code
* The types of requests that you can make
Ajax Example Drag and Drop with JavaScript and css
In Web applications I've seen numerous -and personally implemented a few
ways to rearrange items in a list. All of those were indirect interactions typically involving something like up/down arrows next to each item. The most heinous require server roundtrips for each
modification boo. With sorting vertically oriented items under our belt, onto the next challenge: sorting floated, wrapped list items. Earlier versions of my code had separate scripts for vertical, horizontal, and wrapped lists. Now they are unified into one script that does it
all.
Ajax Building a Drag and Drop
shopping cart
The rise of AJAX over the past several months has taken over the development world and breathed new life into the Web. Although these techniques have been possible for many years now, the maturity of Web standards like XHTML and CSS now make it a viable alternative that will be viewable by all but the oldest browsers.
It's also been possible to accomplish many of the same things using Flex or Flash, but the development cycle with those applications is typically more involved and the overhead often not justified.
We're going to harness the power of the Scipt.aculo.us JavaScript library to provide our interaction. As their Web site states, this library "provides you with easy-to-use, compatible and, ultimately, totally cool JavaScript libraries to make your web sites and web applications fly, Web 2.0 style." We're also going to utilize the <CF_SRS> library to handle the actual AJAX data piping to our application. Both of these libraries are free for all to use, and they're easier to integrate than you would think.
The Better a Ajax and
JavaServer Faces
Browser-based file uploads, in particular those involving the HTML <input type="file"> tag, have always been rather lacking. As I am sure most of you are aware, uploading files exceeding 10MB often causes a very poor user experience. Once a user submits the file, the browser will appear to be inactive while it attempts to upload the file to the server. While this happening in the background, many impatient users would start to assume that the server is "hanging" and would try to submit the file again. This of course, only helps to make matters worse.
In an attempt to make uploading of files more user-friendly, many sites display an
indeterminate progress animation once the user submits the file. Although this technique may be useful in keeping the user distracted while the upload being submitted to the server, it offers very little information on the status of the file upload. Another attempt at solving the problem is to implement an applet that uploads the file to the server through FTP. The drawback with this solution is that it limits your audience to those that have a Java-enabled browser.
Ajax Using the PHP and Sajax
The goal of creating a truly responsive Web application was hampered by one simple fact of Web development: To change the information on part of a page, a user must reload the entire page. Not anymore. Thanks to asynchronous JavaScript and XML (Ajax), we can now request new content from the server and change just part of a page. This tutorial explains how to use Ajax with PHP and introduces the Simple Ajax Toolkit (Sajax), a tool written in PHP that lets you integrate server-side PHP with JavaScript that makes this work.
This tutorial is for those interested in developing rich Web applications that dynamically update content using asynchronous JavaScript and XML (Ajax) with PHP, without having to refresh entire Web pages with each user click. You will learn about Ajax, as well as issues surrounding its usage. You will also build an Ajax application in PHP that will display parts of a previously written tutorial. Then you will integrate the Simple Ajax Toolkit (Sajax) into your Ajax application, which will synchronize the use of Ajax, simplifying development.
The Ajax getting Started
Ajax stands for Asynchronous JavaScript and XML. In a nutshell, it is the use of the nonstandard XMLHttpRequest() object to communicate with server-side scripts. It can send as well as receive information in a variety of formats, including XML, HTML, and even text files. Ajax?s most appealing characteristic, however, is its ?asynchronous? nature, which means it can do all of this without having to refresh the
page. In order to make an HTTP request to the server using JavaScript, you need an instance of a class that provides you this functionality. Such a class was originally introduced in Internet Explorer as an ActiveX object, called XMLHTTP. Then Mozilla, Safari and other browsers followed, implementing an XMLHttpRequest class that supports the methods and properties of Microsoft's original ActiveX object.
The Ajax Developer for prototype
In case you haven't already used it, prototype.js is a JavaScript library written by Sam Stephenson. This amazingly well thought and well written piece of standards-compliant code takes a lot of the burden associated with creating rich, highly interactive web pages that characterize the Web 2.0 off your back.
If you tried to use this library recently, you probably noticed that documentation is not one of its strongest points. As many other developers before me, I got my head around prototype.js by reading the source code and experimenting with it. I thought it would be nice to take notes while I learned and share with everybody else.
I'm also offering an un-official reference for the objects, classes, functions, and extensions provided by this library.
As you read the examples and the reference, developers familiar with the Ruby programming language will notice an intentional similarity between Ruby's built-in classes and many of the extensions implemented by this library.
Ajax
creating autosuggest with JavaScript
Over the past year, Google has branched out from its search engine into other types of Web applications. One that caused a great deal of excitement among Web developers is Google Suggest. The basic idea is very simple: as you type, Google suggests search terms that come up with results. The first suggestion is filled into the textbox as you type while a list of several suggestions appears in a dropdown list beneath the textbox. If you haven't tried it yet, check it out before reading on.
The idea behind Google Suggest is something that has been used in desktop applications for some time and has only recently made it onto the Web. Google Suggest wasn't the first implementation of such an interface
but it popularized the technique among developers to the point where people have dissected the source code and attempted to recreate the functionality.
In building the autosuggest textbox, you will JavaScript in a true object-oriented fashion. The main implementation consists of two types of objects: one to represent the autosuggest control and one that provides the suggestions. The autosuggest control does the heavy lifting in the code by handling all of the user interaction with the textbox.
Ajax How to
Create the suggest with ASP. NET 2.0
It all started when Netscape released Navigator 2.0 in 1996. This browser boosted two revolutionary new features; frames and JavaScript. Although Netscape had different intensions for these features, developers could exploit frames and JavaScript to set up an out-of-band communications channel between the browser and the web server. This made it possible to update forms data without posting back. The concept behind the communications channel was simple. You created a frameset made up of two frames. One of the frames had the height or width attribute set to zero, in practice making the frame ?invisible?. The other frame contained the user interface. When the user clicked a button she triggered a JavaScript function which replaced the location property of the hidden frame with the URL for a CGI script that handled the request. The various parameters were passed thru the query string.
The Ajax is very Dynamic interface
One of the classic drawbacks to building a web application interface is that once a page has been downloaded to the client, the connection to the server is severed. Any attempt at a dynamic interface involves a full roundtrip of the whole page back to the server for a
rebuild-a process which tends to make your web app feel inelegant and unresponsive. In this article, I'll be exploring how this problem can be tackled with the use of JavaScript and the XMLHttpRequest object.
Take the simple example of filling out a serial number box to register a desktop app on a platform like Microsoft Windows. According to convention, once you've finished typing that tiresome string of alphanumeric into the little boxes, a big green 'tick' icon appears to indicate you've entered a valid code. This happens instantly as a result of the interface being sewn to the application; as soon as you finish typing the number, the application is able to check its validity and respond.
The Ajax
make Website in less then 10 Minutes
I've been toying around with AJAX apps and XMLHttpRequest but have wanted to put up a site that loads all of its content asynchronously. If you're like me and you learn best from working with examples you're only 10 minutes away from your first AJAX website.
Angus Turnbull of Twinhelix has written an interesting piece of code named, ?HTMLHttpRequest v1.0beta2? and it?s the perfect start to building your own rich client-side web applications that send and retrieve data to/from a server.
I have done several examples and tutorials on this subject, but this is one of the most complete I?ve seen to date.
This implements both XMLHttpRequest and a custom-written hidden-IFRAME-based transport layer. Therefore, it works in a wider range of browsers, including Opera 7 and IE5/Mac.
Ajax Design Patterns
By now the entire World has heard about AJAX, even those who don?t care about Web-Development have seen the potential of this new technology. Everybody is tired of endless introductions on how cool AJAX is and those endless lists of good examples like Google Suggest, GMail and alike, so I decided to cut a long story short and jump right into the real tutorial.
Well yes and no, it is different in being a tutorial on how to design and build a complete site and not just some fancy little details like how to turn caching in AJAX off or how to create a fancy widget. To keep the tutorial readable, and to avoid having to implement low level functionality, I?m using the dojo toolkit, I tried prototype too and really enjoyed working with being a really nice and easy to use Library, but dojo provides much more functionality bundled with it. For both frameworks one thing is true: documentation is scarse, and I spent alot time debugging and reading posts on the newsgroups.
