3:38 a.m.
I've started reviewing the IdentityManager interface to see where we can
improve the API. The first area I'd like to visit is the Query API, of
which I've come to the conclusion that we need to do some serious
redesign - the current API is non-intuitive, too verbose and not future
proof.
What I'd like to do is throw it all out and start again, replacing it
with a new cleaner API that looks something like this:
public interface IdentityManager {
// <snip other methods>
<T extends IdentityType> IdentityQuery<T> createQuery();
}
public interface IdentityQuery<T extends IdentityType> {
public enum Param {id, key, created, expired, enabled, firstName,
lastName, email, name, parent, memberOf};
public enum Operator { equals, notEquals, greaterThan, lessThan };
IdentityQuery<T> reset();
IdentityQuery<T> setParameter(Param param, Object value);
IdentityQuery<T> setParameter(Param param, Operator operator,
Object value);
IdentityQuery<T> setAttributeParameter(String attributeName, Object
value);
IdentityQuery<T> setAttributeParameter(String attributeName,
Operator operator, Object value);
IdentityQuery<T> setRange(Range range);
List<T> getResultList();
}
This unified API basically replaces the 4 separate existing interfaces
we currently have; UserQuery, RoleQuery, GroupQuery and
MembershipQuery. I've put together a few usage scenarios to show how it
might work:
1) Find users with first name 'John':
List<User> users = identityManager.<User>createQuery()
.setParameter(Param.firstName, "John")
.getResultList();
2) Find all expired users:
List<User> users = identityManager.<User>createQuery()
.setParameter(Param.expired, Operator.lessThan, new Date())
.getResultList();
3) Find all users that are a member of the "Superuser" group
List<User> users = identityManager.<User>createQuery()
.setParameter(Param.memberOf, identityManager.getGroup("Superuser"))
.getResultList();
4) Find all sub-groups of the "Employees" group:
List<Group> groups = identityManager.<Group>createQuery()
.setParameter(Param.memberOf, identityManager.getGroup("Employees"))
.getResultList();
5) Find all disabled roles:
List<Role> roles = identityManager.<Role>createQuery()
.setParameter(Param.enabled, false)
.getResultList();
6) Find all Users, Groups and Roles that have been granted the "Payroll
Officer" role in the "Human Resources" group:
List<IdentityType> identities = identityManager.<IdentityType>createQuery()
.setParameter(Param.memberOf, identityManager.getGroup("Human
Resources"))
.setParameter(Param.memberOf, identityManager.getRole("Payroll
Officer"))
.getResultList();
7) Find all Users that have an attribute named "Citizenship" with a
value of "Greenland":
List<User> users = identityManager.<User>createQuery()
.setAttributeParameter("Citizenship", "Greenland")
.getResultList();
I'm *pretty* certain that this API is at least as capable as what we
currently have, if not more so, and IMHO provides a far simpler and more
versatile design (being able to select different IdentityTypes in a
single query I think is a big plus). I'd love to hear any feedback on
whether you like it, hate it or can think of any improvements to the
design to make it better for our developers. Also, please think
especially about additional usage scenarios and whether or not there are
any particular use cases which might be problematic for this API.
Thanks!
Shane