# Help modeling a User/Group permission structure **URL:** \ **Category:** Rails\ **Created:** [April 29, 2007, 10:18pm UTC](https://www.ruby-forum.com/t/help-modeling-a-user-group-permission-structure/93237 "2007-04-29T22:18:33Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![jim](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/ac91a4/32.png) [@jim](https://www.ruby-forum.com/u/jim)\ **Post date:** [April 29, 2007, 10:18pm UTC](https://www.ruby-forum.com/t/help-modeling-a-user-group-permission-structure/93237/1 "2007-04-29T22:18:33Z")
Hello, I’ve worked through some rails tutorials and am trying to create something a little more complicated for learning purposes. I’m trying to extend a blog application into more of a cms with a basic user/ group permission system. Basically, I have Users, Articles and Groups. Users can have a role of either: Author or Viewer. Some articles are private and some are public. For private articles, I’d like to have a system where an article can be permissioned to either a group or to an individual user or even both. When a website visitor tries to access an article AND the article is ‘Private’, I’d like for the system to prompt the visitor to login. Once logged in, I want the system to then check if this user has permission to view the article. Permission being defined as: if this user is either in a group that has permission to the article OR the user himself has explicit permission to that article. Here’s what I currently have - does this make sense? I’m mostly struggling with the Article\_Private\_Access model and whether this is a good approach. Users: name email password role (role is either ‘Author’ or ‘Viewer’) Group\_Users group\_id user\_id Groups: name Articles user\_id access\_type (‘Private’ or ‘Public’) title body Article\_Private\_Access (\*\* this serves to link Articles with permissioned Users or Groups) article\_id access\_type (‘Group’ or ‘User’) access\_id (this id would point to either a User record, or a Group record) * * * User model: has\_and\_belongs\_to\_many :groups has\_many :article Group model: has\_and\_belongs\_to\_many :users Article model: belongs\_to :user I’m just not sure whether to use the Article\_Private\_Access table and/ or how to model it. I was thinking this table would contain a list of Users and/or Groups that had access to a particular Article. But I’m a bit lost now… Any help would be greatly appreciated. Thanks. ---
**Author:** ![jim](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/ac91a4/32.png) [@jim](https://www.ruby-forum.com/u/jim)\ **Post date:** [May 1, 2007, 7:56am UTC](https://www.ruby-forum.com/t/help-modeling-a-user-group-permission-structure/93237/2 "2007-05-01T07:56:31Z")
The tables you have seem to make sense to me. For the Article Private Access table appears to be a one to one on Article, you could dispense with this table and put the fields into the Articles table. Either as you have them, access\_type, access\_id. Or access\_id, group\_id. With the latter, an article could be accessible by a group or a user or both. If you only want Access by group OR user, then another approach might be to use two different article tables, eg. Group\_Article and User\_Article. I am doing something similar at the moment, where I have bookings that can belong to an Order or a Quote. I am still thinking about it, but it looks to me like having order\_bookings and quote\_bookings may possibly be a cleaner solution. In your case however, that is probably not the case. Others may have better ideas. HTH tonypm ---
**Author:** ![jim](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/ac91a4/32.png) [@jim](https://www.ruby-forum.com/u/jim)\ **Post date:** [May 1, 2007, 3:58pm UTC](https://www.ruby-forum.com/t/help-modeling-a-user-group-permission-structure/93237/3 "2007-05-01T15:58:08Z")
thanks for the response. as for breaking articles into 2 tables, i prefer to keep a single table. i think in your case 2 tables would be better. also, i’m not sure how there would be a 1-1 relationship between my article\_private\_access table with articles. here’s how i envision the data Users id name 1 Jim 2 John 3 Mary 4 Ed 5 Fred Articles id title user\_id access\_type 1 Some article title 1 PRIVATE Groups id name 1 Group1 Groups\_Users group\_id user\_id 1 2 1 4 Article\_Private\_Access article\_id access\_type access\_id 1 Group 1 1 User 3 This would allow “Article 1” (published by Jim) to be accessible by: Group1 (which contains John, Ed) and accessible by user Mary. Fred would not be entitled to access this article Is there an easier way? I feel as though I may have a lot of logic to loop through these Article\_Private\_Access lists that I’d like to simplify. ---
**Author:** ![jim](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/ac91a4/32.png) [@jim](https://www.ruby-forum.com/u/jim)\ **Post date:** [May 1, 2007, 4:00pm UTC](https://www.ruby-forum.com/t/help-modeling-a-user-group-permission-structure/93237/4 "2007-05-01T16:00:08Z")
thanks for the response. as for breaking articles into 2 tables, i prefer to keep a single table. i think in your case 2 tables would be better. also, i’m not sure how there would be a 1-1 relationship between my article\_private\_access table with articles. here’s how i envision the data Users id name 1 Jim 2 John 3 Mary 4 Ed 5 Fred Articles id title user\_id access\_type 1 Some article title 1 PRIVATE Groups id name 1 Group1 Groups\_Users group\_id user\_id 1 2 1 4 Article\_Private\_Access article\_id access\_type access\_id 1 Group 1 1 User 3 This would allow “Article 1” (published by Jim) to be accessible by: Group1 (which contains John, Ed) and accessible by user Mary. Fred would not be entitled to access this article Is there an easier way? I feel as though I may have a lot of logic to loop through these Article\_Private\_Access lists that I’d like to simplify.