From html to xml

(Author: Liao Order December 2000 04 Ri 12:46) XML (eXtensible Markup Language, Extensible Markup Language), is one of the most popular network technology, known as "second-generation Web language", "Next Generation The cornerstone of the network application. " Since it has been put forward, it has almost supported support from all the industry in the industry. So, when XML is now not universal, hurry to grab the priority to keep future rice bowls. HTML disadvantages talk about XML, have to talk about "First Generation Web Language" - Html. HTML is old, has been eliminated (exaggerated, but there is no HTML 4.0, it is replaced by XHTML defined according to XML). Poor us, it's hard to get it, you will use HTML, but I have to discard it. why? HTML can act in driving the vigorous development of WWW in these years. Want to do things on the Internet, almost no HTML can't. But HTML has a fatal disadvantage, that is: is only suitable for communication between people and computers, not suitable for communication with computers. Everyone knows that HTML is to define the documentation in front of us through a lot of tag, that is, HTML is a "display description" language, which describes how web browser should be on page The layout, graphics, etc. are arranged, and there is no description of the most important thing on the Internet. These texts that pass HTML, the graphical content is easy to understand, and it is difficult to understand the meaning of the text within these markers. For example, we design a program that automatically goes to major online shopping malls to catch up with the latest price. But the problem is that each online shopping mall may write a product name and price in the web page, all of them have their own way of writing, such as: price , and price , there is a more complex form. So how do our programs know that what is the price information in the mark? For example, in html, apple represents the case with Apple in a web browser, does not indicate what Apple represents, is Apple? Is Apple? Still what else? This causes HTML not to reveal the meaning of information in the file. In addition, another problem with HTML is that its markings are fixed, and users cannot increase their meaningful tags. Moreover, the specifications of the major browsers do not have the same size, so that we can use the HTML to be displayed normally by all browsers, we can only use W3c to define our defined tags to create a web page. In today's online world, as e-commerce is growing and web-based applications, a large number of information needs to be rapidly processed. In fact, most of the information on the Internet is initially stored in a well-structured database, and the information is stored in the corresponding field, such as employee file, name, gender, department, etc. For "Zhang San" data, the computer can know that it represents an employee's name according to the location it stores. However, once these data is tuned, after converting CGI, ASP, JSP, PHP, the original meaningful data has become a combination of HTML tags without a specific meaning. Users must resolve this data through their own "mind", and "manually" will record them, process, and obviously handle the speed of information.