URLTree URL Router

This package provides a tree-oriented URL router. Most URL routers operate by matching a URL against a list of regular expressions until they find one that matches, but this has obvious performance penalties if there are many routes. URLTree is different; routes are stored as a tree, and matching a URL against the set of routes is equivalent to traversing the tree.

The URLTree router supports parameters, and even allows parameter values to be matched against regular expressions or converted by functions. Moreover, as long as these "restrictions" and the variable names are different, several of these parameters can be declared at the same level of a URL tree; this allows a URL with, say, an integer in one location to be mapped to one destination, while a second URL with non-integer values in that same location may be mapped to another destination.

To use URLTree, allocate a URLTree object and use the URLTree.route() method to map a URL pattern to a destination, like so:

mapper = URLTree()
mapper.route("/article", list_articles, "get")
mapper.route("/article", create_article, "post")
mapper.route("/article/{id}", get_article, "get", id=int)
mapper.route("/article/{id}", update_article, "put", id=int)
mapper.route("/article/{id}", delete_article, "delete", id=int)

Upon receiving a request, the destination and the parameters can be retrieved using the URLTree.resolve() method, like so:

# "req.method" is the HTTP method, and "req.url" is the requested
# URL
dest, params = mapper.resolve(req.method, req.url)

Note that URLTree does not interpret the destination; the examples above use callables, but anything can be used here.