Mapping

The publisher comes with support for object mapping; this is a class or instance on the form:

class Mapper(object):
    def resolve(self, path):
        """Return context given the path tuple."""

    def reverse(self, context):
        """Return path or path tuple."""

A mapper may be provided for a particular route (or routes), or set as the default mapper by passing it to the publisher on instantiation.

It is only used on routes that include an anonymous asterisk, e.g.:

/static/*

The reverse method is optional; only if it’s implemented is the path method available on the route.

Traversal

Object mapping can be used to implement traversal. This is a common operation in object databases where path segments are resolved by calling transitively calling the _getitem__ method of the traversed objects to get the next item.