Advantages and disadvantages of an Ajax-based client

application

Plăcintă Șalaru Mihai-Alin

group 1A

What is Ajax?

Not a programming language.Not a new technology. (a programming

technique)Client-side (Web browsers. i.e FireFox,

Internet Explorer, Opera, Chrome, Safari)Ajax = (Asynchronous Javascript + XML)

Who uses Ajax?

Facebook. (Mostly, ajax utilized)Google. (GoogleDoc, GoogleSuggest,

Gmail, etcs.)Yahoo. (YMail)Meebo. (Multi account of web messenger)And many more modern web application

utilize ajax…

Ajax

Classical website. Need to reload the whole page to return results.

Eg: search results. Time consuming. Old fashion.

Web application using Ajax. Only update the related section without

reloading the entire page.

Why use Ajax

To cut the response time. Reduce network latency.

Asynchronous interaction.Make web application feels like desktop

application.Invisible data retrieval

Updating data behind the scene.Constant updating

Notification

When to use Ajax?

Mostly use in: AutoSave

Save the textbox contents without need to wait for user prompt. (Eg: Gmail compose, blogspot topic post.)

AutoComplete Automatically display the results match. (Eg: Facebook

search.) Paginating

Able to search, sort and organize return data from server. User to user communication

Can you imagine using web chat application that need to reload ENTIRE page for each reply? Insane! (Facebook chat, Gmail chat, YahooMail chat.)

Checking user validity, etc.

Advantages

comes with all modern browsersbetter user interface,responds to user

interaction.low bandwidth, even lower then regular

html/http server applicationsseparation of data, format, style and

function (ajax coding doesn't require this, but makes it a whole )

lot easier to do when it is separated)

Disadvantages

harder/imposible to bookmark Ajax updated page content

network latency delays impact the app's responsiveness

search engine won't crawl AJAX generated content

relies upon javascript, which some users turn off.

browser compatiblity issues.

And...

Well..some browsers are smarter..

Ajax in Web 2.0

Ajax in Web 2.0

Ajax in Web 2.0

Ajax in Web 2.0

Ajax in Web 2.0

Ajax in Web 2.0

Ajax in Web 2.0

Don’t use Ajax for the sake of using Ajax

Remember careful design principles and include ajax only where it makes sense for your application

Ajax in Web 2.0

Ajax in Web 2.0

Failing to visually indicate ajax activity such as busy on status bar, "working" graphic , mouse change,etc

Solution: use graphics, status bar,etc. to indicate "busy"

Ajax in Web 2.0

Leaving people behind Offline Mobile users non-js enabled browsers web accessibility (blind,hearing impaired,etc)

Solution: Provide alternative, traditional implementation when possible to utilize ajax for performance improvements, general ease of use improvements, but not for core functional aspects of a site

Ajax in Web 2.0

Slowness ajax by definition means improved performance,

but poor design can counteract the benefits to much/complex client side logic hitting the server too often sending too much data back and forth

Solution: careful design sensible use of bandwidth

Ajax in Web 2.0

overlooking security sending data in clear texxt sending form data without preprocessing

Solution: encryption and https when needed be mindful of security when designing

Sources:

http://www.slideshare.net/MolecularInc/making-web-20-usable-ajax-case-study

http://en.wikipedia.org/wiki/Ajax_(programming)

http://www.youtube.com/watch?v=p5CTh8aDpsI

Questions?

Thank you!