Having tags per-user is something we might need to address anyway with 
really shared content - I'll add a note to the horde_content stuff 
about it.



Regardless, I think this idea is less attractive after explanation 
than it initially was in my head. So I'm rejecting it for now. 
Obviously just having tags in turba is another matter but also far 
less complicated.

Yes, but if we replace the current contact group implementation with 
tags, we won't be able to add contacts from one source to a group 
within another without some trickery with the tags - like appending 
the source key to the tag. Again, unless I'm missing something which 
is entirely possible. :)



The other concern isn't so much contacts from different sources but 
knowing exactly which groups/tags a particular source contains. My 
thought process is: Individual contacts are tagged, placing them in a 
"group".  When you browse an individual address book source, to know 
what "groups" to display in that source we would need an additional 
query to the tag table/backend to find out which contacts in the 
current address book are tagged with what.



Another thought, what would happen if you have PERMS_READ on a source, 
but want to include a contact from that source in one of your groups?   
You would need to tag that contact, but don't have access to. Another 
issue is how to deal with sources that multiple people have PERMS_EDIT 
on. Tags would have to be per user, since I may not want a contact in 
the same group that someone else with access to that contact does.   
Again, just my observations, and I may be missing something here..

It's already possible to have groups with contacts from different 
sources, if I'm not wrong, so that argument is moot. I share the 
concerns with external sources though. OTOH, the groups could probably 
be mapped to the tags attributes in these cases.

I think the replacing category with tags is a great idea, but I'm not 
so sure about using tags as a replacement for contact groups.  My 
first thought is that this would make it extremely difficult to keep 
sources that are not exclusive to Horde in sync with changes made to 
groups in Horde....and how would we map them the other way? i.e. If an 
external address book source already have groups defined?  I'm also 
wondering about how resource intensive it would be to make the queries 
that would be needed to know what "groups" should be visible when 
browsing an address book etc...  Unless you are talking about 
_completely_ changing how they are displayed in Turba, and not showing 
groups when browsing address books, and instead having each tag 
represent a single group across all sources...in which case I think 
that this would be counter intuitive to how most people use address 
books.  Of course, just my opinion, and I could be totally missing the 
point here :)

I had a wacky idea the other day: what if we replaced both the 
category field, and the Turba_Group stuff (which is kind of wonky) 
with tags? You could treat any tag as a group, and use that for mail 
within IMP or wherever also. In addition, if we could pass along the 
color information for tags to apps using autocompletion, you could see 
your tag's color show up in the IMP address input even.