Revamping URL aliasing

The current system scales poorly Even with 4.7 enhancements, there is a lot more than can be achieved. And it's not really trivial to administer 100K+ aliases. How do we move to a mapping approach while retaining the current flexibility?

Callbacks should not rely on $_GET['q'], only on parameters handed to them. This creates much more reusable code which is a boon in itself.

As a second step we could make the url() and l() functions 'intelligent'. Instead of handing over a simple string, we hand over a type and an id. In most cases this is as simple as splitting at the first slash, but what about the urls that do not look like node/12345?

To continue the system, for each type, we have a function, choosen previously on an admin UI, which creates the path from the type and the id. Incoming URLs can simply be handed by the current menu system: every mapping system adds a menu entry, and from the parameters it finds out the relevant callback and calls it. For example, pathauto paths could look like http://example.com/pathauto/user/username.

To sum up, our tasks are

• make all callbacks clearly parameterized.
• Remove excess arg() usage.
• Decide on the exact mechanism on how we could make the url() and l() functions 'intelligent'.