PHP: friend classes and ungreedy caller function/class

问题

Is there any way to get the caller function with something else than debug_backtrace()?

I'm looking for a less greedy way to simulate scopes like friend or internal.

Let's say I have a class A and a class B.

Until now, I've been using debug_backtrace(), which is too greedy (IMHO).

I thought of something like this:

<?php

    class A
    {
        public function __construct(B $callerObj) {}
    }

    class B
    {
        public function someMethod()
        {
            $obj = new A($this);
        }
    }
?>

It might be OK if you want to limit it to one specific class, but let's say I have 300 classes, and I want to limit it to 25 of them?

One way could be using an interface to aggregate:

public function __construct(CallerInterface $callerObj)

But it's still an ugly code.

Moreover, you can't use that trick with static classes.

Have any better idea?

回答1:

You can call debug_backtrace(FALSE), which will then not populate the object index. This will speed it up a little bit, but generally, debug_backtrace is to be avoided in production code, unless your app is software tool where speed is not an issue or when using it for error handling.

From what I understand, you want to

have an implicit reference to the caller available in the callee and
outside access to private and protected properties to selected classes.

Both does not exist in PHP (and breaks encapsulation imho). For a discussion, please see

[PHP-DEV] reference caller object and
[PHP-DEV] Support for friend classes

回答2:

PHP really doesn't provide you an elegant way of handling this. Without meaning to start a language flamewar, I'm going to gingerly suggest that your design skills and needs have probably exceeded the limitations of your tool. PHP is a lightweight scripting language that's had a lot of pseudo-OOP features bolted onto it, but at its core, it wasn't ever designed for elegant enterprise architecture.

来源：https://stackoverflow.com/questions/2528671/php-friend-classes-and-ungreedy-caller-function-class

标签

php

scope

friend

internal

debug-backtrace