| Despite the intentions of XML's inventors, who mostly envisioned XML as a format for web pages and other narrative documents to be read by people, the most common applications of XML today involve the storage and transmission of information for use by different software applications and systems. New technologies and frameworks (such as Web Services) depend heavily on XML content to communicate and negotiate between dissimilar applications. The structures appropriate for such applications differ from those used for the more traditional narrative documents in XML. They are more rigid in some ways: for instance, they tend to favor strongly typed element content and rarely allow mixed content; while being less rigid in others: the order of child elements rarely matters, for example. Thus, in many applications, the elements tend to look more like database records and less like web pages or books. The appropriate techniques used to design, build, and maintain a record-like XML application vary greatly, depending on the required functionality and intended audience. This chapter discusses a variety of concerns, techniques, and technologies that should be considered when designing a new record-like XML application. |