Using the W3C Reference Library

# Keeping Track of History

The Library supports client applications in keeping track of which locations the user has visited while browsing the Web. The internal history list is implemented in the HTHist module. This module is completely autonomous as it is not used by any other modules in the Library so if it is not referred to in the application code then it will not be linked into the linked application. This means that if the application does not need recording of history then no action is required at all.

The purpose of the history module is to try not to impose any particular history mechanism policy but instead to allow various different history mechanisms. The basic features of the history module are:

- The module can handle multiple history lists
- The underlying data model is linear lists
- The module keeps a position pointer into this list
- The application can refer to an element in the list by an index

Some of the navigation steps supported by the module are "back", "forward", and jump to a position in the list. The details of the module is listed in the declaration part of the HTHist module.