Tài liệu Using Ajax for Web Application Development: What Businesses Need To Know ppt

Using Ajax for Web
Application
Development:
What Businesses
Need To Know
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Introduction
Lately, you may have been hearing more and more about Ajax and you’ve begun to wonder how it could be
beneficial to your business' web application development projects. First, it is important to start with an under-
standing of this type of web programming. While the concept is not new – it has existed since 1998 – the term
did not come into being until February 2005, when Jesse James Garrett coined it as a way to shorten the com-
bination of three technologies that he was going to be using for web application development: Asynchronous
JavaScript and XML.
This recent phrasing may partially explain why Ajax programming has become such a hot
concept for businesses to explore.
Today
, Ajax is being used in web application development by many major players on the web, including
Google, which pioneered its use in a mainstream manner with its Google Maps service, as well as many web-
based email systems
. This is as a direct result of the updating of computer technology in general – today's
average computer user has a faster network connection, a faster machine, and a higher level of computer
knowledge than those used by computers ten years ago. This has opened the door for more complex technolo-
gies to be used by a wider array of websites. On the other hand, web programming using Ajax is not necessary
for a site to be successful; sites such as Amazon and eBay, which are clearly doing well in the business arena,
are either not using this form of web programming at all or are using it sparingly.
Still, web programming with
Ajax has quickly been incorporated into web application development as a new
style.

The Basics of Web Programming with Ajax
At its core, Ajax web programming enables a web application development team to create a site that allows
users to perform certain functions without the need for redrawing or reloading an entire screen. For example,
Google Maps allows users to scroll through a map seamlessly – a technique so revolutionary that it w
as later
adopted by other map sites such as MapQuest and Yahoo Maps. Web-based Email programs using Ajax web
programming allow users to open a message without reloading their entire interface. Sites that allow voting or
rating,
such as Netflix and
Y
ouTube, let users click on an array of stars to rate a film or video without ever
leaving the initial screen. And even shopping sites such as Gap.com use Ajax programming to give users the
feel of a true virtual shopping cart – users place items into their cart without leaving the product page.
In addition, web programming with Ajax can be used to create what are known as "mashups" – situations
where content from two different web applications can be combined into a third, newly useful application. For
example, the apartment listings from Craigslist were crossed with Google Maps to create a site that allows
users to see apartment locations on the map.
Francis Wong, Consultant and Senior Technical Trainer for WestLake
Using Ajax for Web Application Development:
What Businesses Need To Know
Copyright ©2007 Global Knowledge T
raining LLC. All rights reserved.
Page 2
Benefits of Using Ajax for Web Application Development
Web programming with Ajax offers a business several key benefits in its web application development. It offers
site developers an extra level of innovation that can make a site easier to use for all visitors. When implement-
ed correctly, Ajax will also give users the feeling that a web application is more responsive than a traditional
web site. It can also allow a business to give its site new functionality and new services to be used by partners
or clients. Finally, it simply can give parity to a business. Competitors may already be using Ajax on their sites,
and it may be in a business' best interest to have its web application development team implement Ajax on its

own site as well. Customers may also be asking for the new services if they have seen them on other competi-
tor sites.
Caveats for Businesses Considering Ajax Programming
However, there are many things to be careful of when implementing web programming with Ajax as well.
While it does seem lik
e the latest thing, a business should not go overboard in its use during web application
development. Primarily, this type of web programming can make a site more difficult for visitors to use. The
web is at its core a very user-friendly system, but Ajax can introduce new behaviors that people may not be
ready for or may find confusing. This can cause visitors to leave your site quickly
, without actually performing
the tasks, making the purchases, or reading the information that you had provided. Ajax programing can also
create a host of other problems with which businesses should be concerned.
First, and rather simply, using Ajax web programming can cause the back button to behave differently than a
visitor might expect. The bookmark function may also not work as it does on more traditionally programmed
sites. There are ways around these issues that can be implemented during web application development, but
the fixes require a bit of extra time and skill when adding in the additional code.
Ajax programming can also interfere with search engine optimization (SEO) efforts. Search engines will not see
content that may be hidden until revealed by a user's actions. If a business wants to combine Ajax with SEO,
its web application development team will have to be careful to mak
e sure that any optimized content is
alw
ays immediately visible, and that hidden content is not critical to the success of an SEO campaign.
Importantly
, Ajax can open up a webserver to an increased attack surface. This form of web programming
unfortunately gives a hacker more ways to get into the server than there were before. The solution to this is to
mak
e sure that the web application development team is more vigilant about security and testing,
and to con
-
stantly keep watch on the activity occurring on the site. In addition, since different browsers read Ajax differently,

the web application development team will also have to do additional testing for accessibility.
Conclusion
T
he issues with
Ajax are rather widely known.
Now the critical issue is how this type of web programming can
be useful for businesses that are creating and updating their websites
. The most important thing to remember
when exploring the use of Ajax with web application development is to use it with caution and with care.
Overuse or improper implementation can cause major issues to a website, but when used judiciously, it can
bring new functionality and new features to a site. And that can lead to more, happier visitors, which is always
the goal.
Copyright ©2007 Global Knowledge T
raining LLC. All rights reserved.
Page 3
Learn More
Learn more about how you can improve productivity, enhance efficiency, and sharpen your competitive edge.
Check out the following Global Knowledge course:
1809 Fundamentals of AJAX Programming
For more information or to register, visit www.globalknowledge.com or call 1-800-COURSES to speak with a
sales representative.
About the Author
Francis Wong is an independent consultant and senior technical trainer for WestLake Training and
Development. He has developed software applications for many well-known companies such as AOL, Hitachi,
F
annieMae, and Marriott for over 19 years. Mr. Wong has also developed online and on-site technical training
for programmers and managers and delivered courses throughout the United States as well as Bangalore,
India. He can be reached through WestLake (Westlaketraining.com/approach/delivery-optioins.html) or contact-
ed directly at francis.wong~at~keybillable
.com.

Copyright ©2007 Global Knowledge T
raining LLC. All rights reserved.
Page 4