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" b ...
, used for example in the
SOAP
Soap is a salt of a fatty acid used in a variety of cleansing and lubricating products. In a domestic setting, soaps are surfactants usually used for washing, bathing, and other types of housekeeping. In industrial settings, soaps are use ...
protocol. This pattern is useful when a message, or parcel of data, requires considerable
metadata
Metadata is "data that provides information about other data", but not the content of the data, such as the text of a message or the image itself. There are many distinct types of metadata, including:
* Descriptive metadata – the 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 arbitrary data. It defines a set of rules for encoding documents in a format that is both human-readable and machine-readable. T ...
is employed for both head and body (see also
XML Protocol
The XML Protocol ("XMLP") is a standard being developed by the W3C XML Protocol Working Group to the following guidelines, outlined in the group's charter:
# An envelope for encapsulating XML data to be transferred in an interoperable manner that ...
).
XML
Software design patterns
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