Understanding Web Page Tools Language XML (iv) application classification _xml/rss

IV. Application Classification of XML

The overall application of XML can be grouped into four categories:

(1) To be applied to the customer when interacting with different data sources. The data may come from different databases, and they all have different complex formats. But customers interact with these databases through only one standard language, which is XML. Because of the customization and extensibility of XML, it is sufficient to express various types of data. Customers can process data after they receive it, or they can pass between different databases. In a word, XML solves the problem of unified interface of data in this kind of application. However, unlike other data-passing standards, XML does not define the specific specification of data in the data file, but instead appends tag to the data to express the logical structure and meaning of the data. This makes XML a specification that the program can automatically understand.

(2) applies to the distribution of a large number of operational load on the client, that is, customers can choose and produce different applications to process data according to their own needs, and the server only needs to emit the same XML file. Still, for example, the traditional "client/server" approach to work, customers send different requests to the server, the server to respond, which not only aggravate the load on the server itself, but also network managers need to investigate a variety of different user needs in order to make corresponding different procedures, but if the user's needs are complex and changeable, It is not appropriate to concentrate all business logic on the server side, because the server-side programmers may not be able to meet the needs of many applications, too late to keep up with the changes in demand, both sides are very passive. The application of XML will be the process of processing data to the customer, the server is just as perfect as possible, accurately encapsulate the data into the XML file, it is the right to do their own duties. The self explanatory nature of XML makes it possible for the client to understand the logical structure and meaning of the data while receiving the data, so that wide and universal distributed computing can be made.

(3) It is used to present the same data to different users in different faces. This application can also be reflected in the above example. It is similar to the same script, but we can use TV dramas, movies, plays, cartoons and other forms of expression. This application will pave the way for the personalized and stylized development of the Web user interface.

　　(4) applied to the network agent to edit the information obtained, to adapt to the needs of individual users. Some customers get data not for direct use but for organizing their own databases as needed. For example, the Ministry of Education set up a large test bank, the examination of the questions in the question to take out a number of composition papers, and then the paper into the XML file, the next is the most exciting part, in each school let it through a filter, filter out all the answers, and then sent to each candidate Unfiltered content can be sent directly to the teacher's hands, of course, after the examination can also send a copy of the answer compiled. In addition, the XML file can also include other relevant information such as difficulty coefficient, error rate of previous years, and so on, so that only a few small programs, the same XML file can be converted into multiple files to the hands of different users.