Multiple inheritance of user groups

User groups can inherit permissions from other user groups. 

Suppose:

• we have a user group C that inherits from A, and
• we have a class CLASS with a field FIELD.

The following rules are relevant:

1. Suppose user group A has read permission on class CLASS. And user group C has only update permission on class CLASS. This means that users in user group C are allowed to update records of class CLASS.
   
   
2. Suppose user group A has read permission on class CLASS and 'Permitted fields only' is set to true. However, there are no field permissions set for user group A. User group C has no read permission on class CLASS, but has a read permission on a particular field FIELD. This means that users in user group C are allowed to read FIELD.
   
   
3. Suppose user group A has search permission on class CLASS and but has no read permission on the same class. This implies that none of the fields can be used to search. User group C has no search permission on class CLASS, but has a read permission on a particular field FIELD. This means that users in user group C are allowed to search on FIELD.
   
   
4. Suppose user group A has a read permission value on class CLASS 'Helper' but there is no helper defined. This implies that nothing can be read. User group C has a helper defined. This means that this helper is applied to define if users in user group C can read class CLASS.
   
   
5. Suppose user group A has a read permission value on class CLASS 'User related' but there is no route to the user class defined. This implies that nothing can be read. User group C has a route defined. This means that this route is applied to define if users in user group C can read class CLASS.

In the near future, user groups can inherited permissions from more than one other user group.

Suppose C has two parents.

In case conflicting permissions are inherited from two or more parents, the following rule is applied:

Basic rule: The first user group in the list of parents supercedes the second, and so on. 

Please be aware of the following cases:

1. Suppose user group A has read permission on class CLASS. And user group B has no read permission on class CLASS but has update permission on class CLASS. In practice, this means that User group B is not allowed to update records of class CLASS because read permission is also required. So both parents are not allowed to update record of class CLASS.
   
   User group C inherits both permissions from both parents, and therefore users in user group C are allowed to update records of class CLASS.
   
   
   

2. Suppose user group A has read permission on class CLASS and 'Permitted fields only' is set to true. However, there are no field permissions set for User group A. User group B has no read permission on class CLASS but has a read permission on a particular field FIELD. So both parents are not allowed to read fields of class CLASS.

   User group C inherits both permissions from both parents, and therefore users in user group C are allowed to read FIELD.
   
   

3. Suppose user group A has search permission on class CLASS and but no read permission. This implies that none of the fields can be used to search. User group B has no search permission on class CLASS but has a read permission on a particular field FIELD. So both parents are not allowed to search on class CLASS.

   User group C inherits both permissions from both parents, and therefore users in user group C are allowed to search on FIELD.
    

4. Suppose user group A has a read permission value on class CLASS 'Helper' but there is no helper defined. This implies that nothing can be read. User group B has a helper defined. So both parents are not allowed to read class CLASS.
   
   User group C inherits the permission from one parent and the helper from the other. And therefore the helper is applied to calculate whether users in user group C can read class CLASS.
   
   

5. Suppose user group A has a read permission value on class CLASS 'User related' but there is no route to the user class defined. This implies that nothing can be read. User group B has a route defined. So both parents are not allowed to read class CLASS.
   
   User group C inherits the permission from one parent and the route from the other. And therefore the route is applied to calculate whether users in user group C can read class CLASS.