The head–body pattern is a common XML

design pattern A design pattern is the re-usable form of a solution to a design problem. The idea was introduced by the architect Christopher Alexander and has been adapted for various other disciplines, particularly software engineering. The " Gang of Four" ...

, used for example in the

SOAP Soap is a salt (chemistry), salt of a fatty acid (sometimes other carboxylic acids) used for cleaning and lubricating products as well as other applications. In a domestic setting, soaps, specifically "toilet soaps", are surfactants usually u ...

protocol. This pattern is useful when a message, or parcel of data, requires considerable

metadata Metadata (or metainformation) is "data that provides information about other data", but not the content of the data itself, such as the text of a message or the image itself. There are many distinct types of metadata, including: * Descriptive ...

. While mixing the meta-data with the data could be done it makes the whole confusing. In this pattern the meta-data or meta-information are structured as the header, sometimes known as the envelope. The ordinary data or information are structured as the body, sometimes known as the payload.

XML Extensible Markup Language (XML) is a markup language and file format for storing, transmitting, and reconstructing data. It defines a set of rules for encoding electronic document, documents in a format that is both human-readable and Machine-r ...

is employed for both head and body (see also XML Protocol). The pattern can be illustrated as:

References

XML Software design patterns {{Compu-prog-stub