Restrict taxonomy terms when users edit content?

Question

I've implemented my site's structure by creating a taxonomy for "areas" and making a term for each area I want in my site (guest info, newbie, facilities, news, and admin). I've let the main menu show these terms as menu items, so that each item shows the content of the corresponding area. When I add content, I specify which area it's for, and this works quite well.

Now, though, I would like to introduce a content type for users to create (for a "user-to-user" area) and I want to hard-code this content type to a specific taxonomy term.

• If I leave out the field for this taxonomy, no term will be assigned. :-/
• If I include the field for this taxonomy, the user can choose a term (and put the page in any area). :-/
• It doesn't look like term assignment is something that can be done with Actions and Triggers. :-/

Is there perhaps a module that provides control over what terms are available for a given situation (user/role/content type)? I've googled, but all I can find is acces control modules for users and nodes, not taxonomy terms.

Edit: To be clear, I'd like to EITHER programmatically set a particular term of a particular vocabulary every time a user of a particular role saves a node of a particular type (but without me having to do PHP programming); OR allow users of a particular role access to only a subset of a particular vocabulary.

Help! :-)

Answer 1

Taxonomy Access Control will let you set up the permissions at the term level.

Access control for user roles based on taxonomy categories (vocabulary, terms).

• Automatically controls access to nodes (based on their taxonomy
  terms).
• Configuration page for each user role.
• Three node access permission types: View, Update, Delete.
• Two term access types: View tag, Add tag.

Answer 2

I'm not aware of any modules that provide this functionality. However, you could write a pretty simple module yourself that automatically assigns the correct taxonomy term. This can be done by adding the field for taxonomy to the content type in question, but not giving users permission to edit the taxonomy terms. It sounds like only the administrator (you) is using this taxonomy vocabulary. Another option would be to simply hide the field (using CSS or other means) on the form.

Either way, use hook_nodeapi() (or hook_node_insert in Drupal 7) to set the value of the taxonomy field automatically when the new node gets created. This way you're guaranteed that each user created node has the correct taxonomy terms.