# Check if user is in right group **URL:** \ **Category:** Rails\ **Created:** [January 28, 2006, 2:16pm UTC](https://www.ruby-forum.com/t/check-if-user-is-in-right-group/98244 "2006-01-28T14:16:55Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![Henrik\_SSiso-8859-1](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/h/3be4f8/32.png) [@Henrik\_SSiso-8859-1](https://www.ruby-forum.com/u/Henrik_SSiso-8859-1)\ **Post date:** [January 28, 2006, 2:16pm UTC](https://www.ruby-forum.com/t/check-if-user-is-in-right-group/98244/1 "2006-01-28T14:16:55Z")
What is the best way of checking this? I have 3 tables: groups users group\_members class GroupMember \< ActiveRecord::Base belongs\_to :group belongs\_to :user validates\_uniqueness\_of :user\_id, :scope =\> “group\_id” Then I want a method here that checks if a given user is a member of a given group. What is the right way of doing that? def is\_member\_of(user, group) ?? end Regards, Henrik ---
**Author:** ![Henrik\_SSiso-8859-1](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/h/3be4f8/32.png) [@Henrik\_SSiso-8859-1](https://www.ruby-forum.com/u/Henrik_SSiso-8859-1)\ **Post date:** [January 28, 2006, 2:53pm UTC](https://www.ruby-forum.com/t/check-if-user-is-in-right-group/98244/2 "2006-01-28T14:53:07Z")
If a member can be in more than one group I would use a has\_and\_belongs\_to\_many relationship. You create a table called groups\_users and in taht table you have primary keys set for user\_id and group\_id you can also add other fields into that table for permissions and anything else. Than you need to set foreign key relationships (also indexes) that reference the respective id’s in the other tables. The HABTM table does not have an id column in it. If a user can only belong to one group I would get rid of the group\_members table. This is something that I used in PHP allot but it is not needed on rails with the great relationship support. As far as a check to see if a user is a member of a group It depends on what you are looking to display? if it content specific to the group when they access the page call a find that has the constraint of looking for the group\_id in the users table (foreign key relationship of has one) or look in groups\_users table to pull the users for that particular group. Andrew ---
**Author:** ![Henrik\_SSiso-8859-1](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/h/3be4f8/32.png) [@Henrik\_SSiso-8859-1](https://www.ruby-forum.com/u/Henrik_SSiso-8859-1)\ **Post date:** [January 28, 2006, 3:11pm UTC](https://www.ruby-forum.com/t/check-if-user-is-in-right-group/98244/3 "2006-01-28T15:11:18Z")
Thanks for the fast reply :-). An user can be an member of a lot of groups. The GoupMember class i supposed to do a lot of things. I therefore deliberately chose to use this class instead of HABTM (as recommended it the Aguile book “When a join wants to be a model”, page 241). The problem is that I just haven’t yet got the whole grasp of this magic here in AR. I have started with: def is\_member\_of(user, group) @user = User.find(:id, :condition =\> [“uname = ?”, user]) @group = Group.find(:id, :condition =\> [“name = ?”, group]) end But I guess it is more clever ways of doing this in Rails. Beside I’m not sure how to continue in this method. - Henrik Sat, 28 Jan 2006, Andrew F. skrev: > as a check to see if a user is a member of a group It depends on what > > > belongs\_to :user > > Henrik > > > > * * * > > > > Rails mailing list > > removed\_email\_address@domain.invalid > > [http://lists.rubyonrails.org/mailman/listinfo/rails](http://lists.rubyonrails.org/mailman/listinfo/rails) > > * * * > > Rails mailing list > removed\_email\_address@domain.invalid > [http://lists.rubyonrails.org/mailman/listinfo/rails](http://lists.rubyonrails.org/mailman/listinfo/rails) > Henrik Ormåsen – SOS Rasisme er Norges eneste demokratiske medlemsorganisasjon som konsentrerer seg om å arbeide mot rasisme og nazisme. Vi har over 40.000 individuelle medlemmer, 8.000 kollektive medlemmer og 90 lokallag. Vi er Europas største antirasistiske organisasjon. Har du lyst til å bli medlem? Gå til: www.sos-rasisme.no/blimedlem Har du lyst til å bli aktiv? Gå til: www.sos-rasisme.no/bliaktiv PB 9427, Grønland -0135 OSLO Besøk oss i Brugata 14, 0186 Oslo (Samme bygg som 7 Eleven) telefon: 23 00 29 00 direkte: 23 00 29 06 faks: 23 00 29 01 mobil: 48 18 14 92 ---
**Author:** ![Henrik\_SSiso-8859-1](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/h/3be4f8/32.png) [@Henrik\_SSiso-8859-1](https://www.ruby-forum.com/u/Henrik_SSiso-8859-1)\ **Post date:** [January 28, 2006, 4:14pm UTC](https://www.ruby-forum.com/t/check-if-user-is-in-right-group/98244/4 "2006-01-28T16:14:41Z")
Hello Kevin! Thanks for your advise. I have from before installed the old login generator. I should probably upgrade to this one. But I’m still little unhappy about my missing understanding of the possibilities of this case. Even if the user|login\_engine will solve my problem here, I will eventually get the same problem later. I’m working with a news publishing system where the grouping system will be a very important thing. But thanks anyway. I no body will help me with my silliness limiting my ability here, I can try to read some open code and see if I can get some out of it. - Henrik Sat, 28 Jan 2006, Kevin O. skrev: > If you want to only permit user assigned to a particular role to be able > > :conditions =\> [“visible\_to = ?”, role\_id] > > Actually… you would need to set up the query to pick up items in any > of the user’s roles, since they can have more than one. > > That combination of controller/action access control and record level > control should cover most use cases. > > \_Kevin Henrik Ormåsen – SOS Rasisme er Norges eneste demokratiske medlemsorganisasjon som konsentrerer seg om å arbeide mot rasisme og nazisme. Vi har over 40.000 individuelle medlemmer, 8.000 kollektive medlemmer og 90 lokallag. Vi er Europas største antirasistiske organisasjon. Har du lyst til å bli medlem? Gå til: www.sos-rasisme.no/blimedlem Har du lyst til å bli aktiv? Gå til: www.sos-rasisme.no/bliaktiv PB 9427, Grønland -0135 OSLO Besøk oss i Brugata 14, 0186 Oslo (Samme bygg som 7 Eleven) telefon: 23 00 29 00 direkte: 23 00 29 06 faks: 23 00 29 01 mobil: 48 18 14 92 ---
**Author:** ![Henrik\_SSiso-8859-1](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/h/3be4f8/32.png) [@Henrik\_SSiso-8859-1](https://www.ruby-forum.com/u/Henrik_SSiso-8859-1)\ **Post date:** [January 28, 2006, 4:38pm UTC](https://www.ruby-forum.com/t/check-if-user-is-in-right-group/98244/5 "2006-01-28T16:38:51Z")
Henrik, if you want to keep the UserGroup model you first posted, how about class User \< AR:B has\_many :group\_members def member\_of?(group) group\_members.include? group end end class Group \< AR:B has\_many :group\_members end cheers Gerret ---
**Author:** ![Henrik\_SSiso-8859-1](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/h/3be4f8/32.png) [@Henrik\_SSiso-8859-1](https://www.ruby-forum.com/u/Henrik_SSiso-8859-1)\ **Post date:** [January 28, 2006, 11:55pm UTC](https://www.ruby-forum.com/t/check-if-user-is-in-right-group/98244/6 "2006-01-28T23:55:03Z")
Thanks everybody. I’ve converted to the user|login engine. It looks really nice, and I guess its anyway a good thing to have this part separated from rest of the app like this engine thing does. Nice to be able to update it without a lot of work :-). Also thanks to Gerret, small thing when you know it :-). - Henrik ---
**Author:** ![Henrik\_SSiso-8859-1](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/h/3be4f8/32.png) [@Henrik\_SSiso-8859-1](https://www.ruby-forum.com/u/Henrik_SSiso-8859-1)\ **Post date:** [January 28, 2006, 3:13pm UTC](https://www.ruby-forum.com/t/check-if-user-is-in-right-group/98244/7 "2006-01-28T15:13:57Z")
Henrik =?iso-8859-1?Q?Orm=E5sen?= wrote: > Then I want a method here that checks if a given user is a member of a > given group. What is the right way of doing that? You can do a lot of this kind of stuff using ‘roles’ from the ‘user|login\_engine’. You can restrict access to specific controller/action pairs using that system (which works nicely IMO). If you want to only permit user assigned to a particular role to be able to see an object, you would need some sort of association describing which roles can see the object. In some cases you could make it as simple as having a ‘visible\_to’ column and populating that with the id of the appropriate role. Then you modify your find method to be something like… @object = Object.find\_all\_by\_visible\_to(role\_id) or add a condition like… :conditions =\> [“visible\_to = ?”, role\_id] Actually… you would need to set up the query to pick up items in any of the user’s roles, since they can have more than one. That combination of controller/action access control and record level control should cover most use cases. \_Kevin