Six misunderstandings of Ajax

Just like the Flash font and Splash pages that have been popular before, there is often a "Skip Introduction" or "directly enter" button), and the use of rounded corners (TRANSLATOR: see YeeYan homepage, haha), but this time is more dynamic?

Let's look at several misunderstandings about Ajax, open the fog, and discover the truth.

Misunderstanding 1: AJAX is short for Asynchronous JavaScript and XML. When you write this word, you should use uppercase letters for spelling, or you will not be very ignorant.

In fact, according to Jesse James, the creator of Ajax, Ajax is more than just a acronym. It is a combination of a series of technologies in a specific way. It includes JavaScript, CSS, DOM, and data transmission between the client and server using XMLHttpRequest objects. The format of data transmitted from the server to the client is not necessarily XML, but JSON (an object in Javascript) or other data formats. In short, data transmission is small and incremental (TRANSLATOR: instead of refreshing the entire page in the traditional way ). Therefore, if you want to show that you are a very knowledgeable Technical Expert, use Ajax instead of AJAX. You can determine whether you want to show yourself.

Misunderstanding 2: Check Gmail and Google Map. Ajax will make your website more available.

In fact, using Ajax may enhance the availability of your website, but it may also make your website ugly and difficult to use. The newly designed Yahoo TV program list is such a negative textbook. (TRANSLATOR: The negative comment on the new version of Yahoo TV program list mainly believes that Ajax's page flip function makes the availability of all TV programs listed on the previous page worse, for example, you cannot search on one page, even though the page turning function itself is very beautiful .)

Misunderstanding 3: Ajax is just a face project-it looks cool and visual on the surface.

In fact, if there is a correct design and implementation, Ajax network applications should be subject to server-side processing (such as ASP. NET or Java Server Pages, JSP) network applications have better scalability, and allow users to experience faster response speed. For technical details, see the first section about Ajax and REST written by IBM Bill Higgins. This is my summary: Traditional CGI type network applications that take server-side processing as the main body, clients do not save (network applications execute) status (Stateless ), state storage is fully implemented by the server (Stateful server ). This allows the server to generate results (for example, data that is dynamically read from the database) that can only be used at one time rather than cached for reuse. This breaks the scalability principle in the REST architecture. While Ajax can save the status on the client to implement common resources, such as repeated data and source programs (TRANSLATOR: Javascript), which can be effectively cached and reused.

Misunderstanding 4: Ajax is hard for general network developers to grasp

Ajax is really not easy. However, its usage difficulty is gradually decreasing. There are several factors that make it difficult to implement Ajax: Compatibility support for different browsers, lack of development tools, as well as the requirements for the transformation of developers' mindset-from the previous network applications with server-side processing as the main body, to new applications that store status on the client and gradually upload data. However, due to the increasing popularity of Ajax, many development tools, platform providers, and open-source software developers are working hard to solve this problem. Here we will list several tools useful to Ajax developers: Google network development toolbox (for Java developers), dojo cross-browser platform, and script. aculo. the us supervisor provides visual effects, as well as Firebug for debugging JavaScript programs and monitoring XMLHttpRequest (FireFox plug-in.

Misunderstanding 5: Ajax will damage the user's browser experience (Ajax breaks the browser model)

Indeed, Ajax applications may cause problems in browser usage. For example, if the "Return key" function is broken, users are unaware of the function, and users with disabilities cannot use the website at all. However, traditional technologies may also produce similar problems: for example, using a framework (frames) or Flash may also damage the "Return key" function. Even if Ajax is not used, poor design can make a website completely confuse users. Even the simplest HTML is difficult for users with disabilities to use the website smoothly. These are aspects that require conscious attention and learning. They are not only problems in Ajax applications.

Misunderstanding 6: Ajax is a key component of web2.0

It depends on how you define web2.0. I think the main difference between web and web lies in the social layer rather than the technical layer. The most important paradigm shift from web1.0 to web2.0 is that web2.0 is a bidirectional network, a readable network and a social network. Instead of the network that "lets us buy online stores. According to this definition, we can implement web2.0 without Ajax at all. Most blogs do not use Ajax. Without Ajax, Wikipedia is still able to shine. Social networks do not need Ajax. The reason why Flickr is attractive is that it is a social platform for photos, instead of using DHTML technology.

More information about Ajax (recommended for deep reading, recommendation, and translation)

My personal favorite Ajax blog is Ajaxian and Shelley Power's "Tech female madman ". Shelley's "add Ajax" will soon be published by o'reilly. The writing in this article refers to the article on Ajax and REST architectures by Bill Higgins (part 1 and part 2 .)

Statement: IBM is my customer.

Translator: the question picture is the original author's picture. In addition, the original article contains the detailed contact information of the original author.