SWI-Prolog -- http:location/3

[nondet,multifile]http:location(+Alias, -Expansion, -Options)

Multifile hook used to specify new HTTP locations. Alias is the name of the abstract path. Expansion is either a term Alias2(Relative), telling http_absolute_location/3 to translate Alias by first translating Alias2 and then applying the relative path Relative or, Expansion is an absolute location, i.e., one that starts with a /. Options currently only supports the priority of the path. If http:location/3 returns multiple solutions the one with the highest priority is selected. The default priority is 0.

This library provides a default for the abstract location root. This defaults to the setting http:prefix or, when not available to the path /. It is advised to define all locations (ultimately) relative to root. For example, use root('home.html') rather than '/home.html'.