Hi Bo
I think you may need to pull back and describe your overall goals here. Your original post included this idea:
> My idea was to set _canonical_uri for the $:/status/UserName to a lokal .tid-file (username.tid) so that the username is transcluded by that file.
The trouble is that _canonical_uri only works in certain circumstances, and when it does, it works asynchronously. I don’t think you’ll be able to get this to work in the way that you describe. The code that reads the username from that tiddler doesn’t know how to resolve the _canonical_uri field, and as I say, it’s synchronous, so couldn’t work anyway.
Best wishes
Jeremy