Forum OpenACS Q&A: Response to How to get an instance url from a package key?

It's been almost a year, but what I had in mind at a time, was the problem of one package needing to create redirections to another package, in the case where the targeted package might not be a singleton.

So your package wants to include redirects to adserver or clickthrough or all sorts of things that may not be mounted relative to your package.  If the target is not a singleton, and if the context isn't specified by user_id or something similar, how can anything determine the proper URL.

I don't know if this has been solved or not.  I solved it in the limited case of the adserver as the adserver was a singleton.  But I can certainly imagine cases when the adserver is not a singleton, you want different ads (and maybe different adserver instances) depending on the subsite, or gender, or zip code, or time of day, referrer_url, shopping cart contents, ....  What sort of things can be done by the implementor to address this?