Hi, I know the subject was discussed years ago, and it was decided not to implement 'friend class' declarations (see https://bugs.php.net/bug.php?id=34044).
But the discussions occurred ten years ago, and things (and people) may be different now. Unfortunately, there is no easy-to-use and fast solution for this yet. Most projects have asked for such a feature for years but, till now, they still have to rely on a big warning in the documentation. Some, like symfony, also add an '@internal' tag in their phpdoc block. This can be checked in an IDE but that's information, not access restriction. IMHO, such a feature would be a valuable addition for PHP 7. If you agree, I will write an RFC. The feature I was thinking about would be globally similar to C++ friend classes, except that a PHP friend class would have access to protected resources, but not private ones (private would remain private). The inheritance rules would be similar to C++ rules (adapted from Wikipedia as it originally includes access to private resources) : * Friendships are not symmetric If class A is a friend of class B, class B is not automatically a friend of class A. * Friendships are not transitive If class A is a friend of class B, and class B is a friend of class C, class A is not automatically a friend of class C. * Friendships are not inherited A friend of class Base is not automatically a friend of class Derived and vice versa; equally if Base is a friend of another class, Derived is not automatically a friend and vice versa. * Access due to friendship is inherited A friend of Derived can access the protected members of Derived that were inherited from Base (simpler than the C++ rule as friend classes and derived classes have the same access rights). Another idea would be to base access restriction on namespaces, but, IMO, namespaces would not bring the precision we need : each class needs to define which classes are accepted as 'friends'. Please comment. Regards, François -- PHP Internals - PHP Runtime Development Mailing List To unsubscribe, visit: http://www.php.net/unsub.php
