====== Requirements ======

  * A group can have multiple group owners .
  * Active members can become group owners. 
  * A group owner can add and remove himself and other members as/from owners .
  * A group owner can cancel his own membership and other owner’s membership aswell .


====== Present Design ======
  * Single group owner for each group .
  * Group owner info only present in Groups model as owner_id column.


====== Implementation ======

===== Approach =====
    * Handle the multiple group ownership privilege through group_membership model by adding an 'is_owner' column (type :boolean)  in group membership model  .
        * Members controller => add_to_group_owners action : updates the 'is_owner' flag of the respective membership record  to true to grant group ownership privilege .
        * Members controller => remove_from_group_owners   : updates the 'is_owner' flag of the respective membership record  to false to remove group ownership privilege .

    * All group ownership related scenarios (for privileges to the group owner) and checks are now done through group_membership model (in contrast to referring the groups model under present implementation) .

===== Model Level Changes =====
The following methods were added in groups model to handle addition and removal of group members as owners  .
    add_as_owner
       Updates the is_owner column of membership record to true.
    
    remove_as_owner
       Updates the is_owner column of membership record to false.

        
The following columns are added in existing tables :  
  
Table name - group_membership

^ Column_name       ^type       ^ Description   ^
| is_owner | boolean           | when set indicates a member with owner privilege and when unset indicates a normal group member   | 


Associations modified :
   User model :
   has_many :owned_groups, :through => :memberships , :source => :group , :conditions => ['is_owner = ?',true], :foreign_key => 'user_id'
   

===== Work Flow =====
  * Once a user creates a group , the membership record is created with the is_owner flag set to true .
  * An owner has the privilege to add other active members as owners or remove them from the owner list .
  * If a member is already a member of the group the 'Add to group owners' link changes to 'Remove from group owners'.
  * If the member is the only owner of the group , the 'Cancel' and 'Remove from group owners' links are disabled for him.
  * Owner being a group member also gets enrolled in the In Person Events -> auto enroll option.
  
 ===== Note ===== 
  * User suspension and trasfering ownership scenario from Manage Site -> User Management :
        * If the owned group of the user have multiple owners them the ownership of the groups are not changed .
        * If the owned group of the user do not have multiple owners , the the ownership is changed from transferror(current owner) to transferee(new owner) .