Ajax technology entry and its applicability

What Is Ajax technology?

Ajax is called "Asynchronous JavaScript and XML" (Asynchronous JavaScript and XML). It is a Web page development technology used to create interactive web applications. It organically includes the following technologies:

Based on the Web Standard (Standards-based presentation) XHTML + CSS representation; Use dom (Document Object Model) for Dynamic Display and interaction; use XML and XSLT for data exchange and related operations; use XMLHttpRequest for asynchronous data query and retrieval; use JavaScript to bind everything together. Similar to DHTML or lamp, Ajax does not refer to a single technology, but organically utilizes a series of related technologies. In fact, some Ajax-based "derived/synthesized" (derivative/composite) technologies are emerging, such as "aflax ". Ajax applications use Web browsers that support the above technologies as the operating platform. These browsers currently include Mozilla, Firefox, Internet Explorer, opera, Konqueror, and safari. However, opera does not support XSL format objects or XSLT. Ajax-based application architectureBrowser-side frameworks are divided into two categories: • application frameworks: Provide browser functions, but are often known to include abstract widgets and other components, its functions mainly focus on the desktop GUI framework. • Basic Structure Framework: provides basic pipelines and portable browser abstractions for developers to create content. Application Scope of AJAX Ajax Applicable scenarios1. Form-driven interaction traditional form submission. after entering the content in the text box, click the button. After the background processing is complete, the page is refreshed, and then you can check whether the refresh result is correct. With Ajax, after clicking the "sunmit" button, asynchronous processing is performed immediately, and the updated results are displayed quickly on the page. There is no problem with refreshing the entire page. 2. in-depth tree navigation deep cascading menu (tree) traversal is a very complex task, using JavaScript to control the display logic, loading deeper data with Ajax latency can effectively reduce the burden on the server. 3. quick user-to-user interaction and response in scenarios where many people are involved in communication and discussion, the most unpleasant thing is to let the user refresh the page over and over again to know whether there is a new discussion. New replies should be shown as quickly as possible, and Ajax is the best choice to free users from the refreshing of distraction. 4. in scenarios like voting and YES/NO, if the submission process takes 40 seconds, many users will ignore the past and will not participate, however, AJAX can control the time within one second, so that more users can join in. 5. Use filters to filter and manipulate data, Sort data by time, or by time and name, and switch filters. Javascript should be used for any scenario requiring highly interactive data manipulation, rather than a series of server requests. After each data update, it takes a lot of time to search for and process the data. Ajax can accelerate this process. 6. common text input prompts and auto-completion scenarios are prompted in input forms such as text boxes, or automatically completed, which can effectively improve the user experience, ajax is a good choice, especially for scenarios where automatically completed data may come from the server. Ajax Unsuitable scenarios1. Some simple forms although form submission can obtain the greatest benefit from Ajax, a simple comment form rarely gets significant improvements from Ajax. Ajax is not helpful for some forms that are rarely used. 2. some search engines that use Ajax such as start.com and live.com do not allow the browser's back button to view the previous search results, this is intolerable for users who have developed search habits. 3. It is a bad idea to use Ajax for website navigation. Why don't we put the time on making system programs better? 4. Replacing a large amount of text with AJAX can achieve partial page refresh. But if every part of the page changes, why not re-create a server request? 5. manipulating Ajax on rendering looks like a pure UI technology, but in fact it is not. It is actually a technology for data synchronization, manipulation, and transmission. It is a good idea to not use ajax to control page rendering for maintainable and clean web applications. Javascript can easily process xhmtl/html/DOM, and use CSS rules to express data display. Reference: http://www.javaeye.com/topic/38793