On the advanced and limitation in AJAX technology

Advancement:

1. Form-driven interaction

Traditional form submission, after the text box input, click the button, the background processing finished, the page refresh, and then look back to check whether the refresh result is correct. Using AJAX, after clicking on the Sunmit button, immediately asynchronous processing, and on the page quickly show the results of the update, there is no overall page refresh problem.

2. Deep-rooted tree navigation

The Deep cascading menu (tree) traversal is a very complex task, using JavaScript to control the display logic, using AJAX to delay loading deeper data can effectively reduce the burden on the server.

3. Fast communication between users and users

The most frustrating thing about being involved in the conversation is to have the user refresh the page over and over again to see if there is a new discussion. New responses should be displayed as quickly as possible, and Ajax is the best choice to free users from distracting refreshes.

4. Online survey

In a scenario like this, if the commit process needs to reach 40 seconds, many users will simply ignore the past and not participate, but Ajax can control the time within 1 seconds, so that more users will join in.

5. The scene of filtering and manipulating relevant data for data

Use filters for data, sorted by time, or sorted by time and name, switch filters, and so on. Any situation requiring highly interactive data manipulation should be done using JavaScript, rather than a series of server requests. After each data update, it takes more time to find and process it, and Ajax can speed up the process.

6. Normal text input prompts and automatic completion of the scene

Typing prompts in input forms such as text boxes, or automating them, can be an effective way to improve the user experience, especially if the automatically completed data may come from a server-side situation, Ajax is a good choice.

Limitations:

1. Some simple forms

Although form submission can get the most benefit from Ajax, a simple comment form rarely gets any noticeable improvement from Ajax. While some of the less-used forms are submitted, Ajax is not a helpful one.

2. Search

Some AJAX-enabled search engines such as start.com and live.com are not allowed to use the browser's Back button to view the results of a previous search, which is inexcusable for users who have developed search habits.

3. Basic navigation

Using AJAX to do navigation within a site is a bad idea, why not put time on the system to make it better?

4. Replace a large amount of text

Use Ajax to achieve local refresh of the page, but if each part of the page changes, why not make a server request again?

5. Manipulation of the presentation

Ajax looks like a pure UI technique, but it's actually not. It is actually a technique for data synchronization, manipulation, and transmission. For a clean, maintainable Web application, it's a good idea not to use Ajax to control page rendering. JavaScript can be very simple to deal with Xhmtl/html/dom, using CSS rules can be very good expression of data display.