Limit Taxonomy display in Term Reference based on criteria?

Question

1. I have Taxonomy called "Region" ex: (Region A / B / C)
2. Each user is linked to Taxonomy "Region" using Profile2 module (one person can be linked to multiple regions)
3. Content Type "Article" has a Term Reference field linked to same Taxonomy. (value = unlimited)

Requirement: . In content type "Article", I am asking user to select the Region (as Taxonomy Select list) where this Article belong too - how do I limit the Taxonomy list based on the Region user have an access too?

ex: User1 is linked to Region A / User2 is linked to Region A & B; When User1 creates an Article, Term Reference Taxonomy to show "Region A" but when User2 - show both "Region A" and "Region B"

in SQL world, I would write something like this.

select t.name from taxonomy t where t.name in (select p.name from profile p where user_id = :%1);

How would you achieve this in Drupal without writing custom code?

p.s: My apologies - I am from database world and very new to Drupal; still learning Drupal lingo.

Answer 1

I achieve the behaviour described in the question with:

• Entity Reference
• Views

In my Entity Reference field I use these settings:

• Target type: Taxonomy term
• Entity selection > Mode: Views: Filter by an entity reference view
• Entity selection > View used to select the entities: My custom view

In My custom view entity reference I have (most importantly):

• A relationship: to the user referencing the taxonomy
• A contextual filter: to grab only the terms the user "is linked to"

Related to this question - actually this is what brought me here, In some cases it easier to filter taxonomy terms using a get parameter. For example, I want my visitors to see only the cities of one country when adding a classified ad, I will have a view that produces this:

• Morocco: q=node/add/ad?country_tid=1
• India: q=node/add/ad?country_tid=2
• Zambia: q=node/add/ad?country_tid=3

And on the entity reference view used on the ad content type I will add a contextual filter with a default value generated by this PHP code

return $_GET['country_tid'];

PS. I tried hierarchical select, term reference tree and hook_form_alter. This solution is KISS.

Answer 2

There's a module named Term Reference Tree, which - apart from a nice tree widget - provides an option to filter presented taxonomy items through a result of a view. I mean, I never had to use that option, but I assume it's working ok. However I think you'd have to resort to using that widget then, as well.

Answer 3

If you want to do this without the term reference tree module try the http://drupal.org/project/entityreference module. Just create an entity reference field and you can limit using views.

Answer 4

It worked for me with the following steps

1. Create a view, which list Region based on the user who is logged in (using Relation link in View)

2. content type article, add a new field type=Term Ref then select Term Reference Tree / under field setting select filter by the view created in #1.