Spring Security @PreAuthorize based on custom boolean property value

Question

I have an application where the user enters custom roles name and privileges. Example, the user can create a role named "Human Resources" that has the following properties :

showDashboard = true;
showSuppliers = false;
showEmployees = true;

I want to restrict getSuppliers service based on the showSuppliers property.

@PreAuthorize("WHEN showSuppliers IS TRUE")
public Page<Supplier> getSuppliers();

Role entity :

@Entity
public class Role {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO, generator = "native")
    @GenericGenerator(name = "native", strategy = "native")
    private Long id;

    private String name;

    private boolean showDashboard;
    private boolean showSuppliers;
    private boolean showEmployees;
}

Answer 1

You can reference a bean in the PreAuthorize expression. First this bean/component:

@Component("authorityChecker")
public class AuthorityChecker {

    public boolean canShowSuppliers(Authentication authentication) {
        for (Authority authority : authentication.getAuthorites()) {
            Role role = (Role)authority; // may want to check type before to avoid ClassCastException
            if (role.isShowSuppliers()) {
                return true;
            }
        }
        return false;
    }

}

And the annotation to this will be:

@PreAuthorize("@authorityChecker.canShowSuppliers(authentication)")
public Page<Supplier> getSuppliers();

It will pass the current user's Authentication object to the bean/component above.