自我和静态之间是否存在中间立场?

时间:2013-09-26 21:40:58

标签: php oop static self late-static-binding

我正在寻找SELF和STATIC之间的中间地带,没有后期静态绑定的意外行为。

以下是我的代码,包含练习结果和预期结果:

<?php

class A {
public function get_self() {
    return new self();
}

public function get_static() {
    return new static();
}
}

class B extends A {}

class C {
public function static_get_a_self() {
    return A::get_self();
}

public function static_get_a_static() {
    return A::get_static();
}

public function var_get_a_self() {
    $a = new A();
    return $a->get_self();
}

public function var_get_a_static() {
    $a = new A();
    return $a->get_static();
}


public function static_get_b_self() {
    return B::get_self();
}

public function static_get_b_static() {
    return B::get_static();
}

public function var_get_b_self() {
    $b = new B();
    return $b->get_self();
}

public function var_get_b_static() {
    $b = new B();
    return $b->get_static();
}
}

$a = new A();
$b = new B();
$c = new C();

echo "Static calls: \n";
echo "B::get_self() ============= " . get_class(B::get_self()) .   " | expected A \n";
echo "B::get_static() =========== " . get_class(B::get_static()) . " | expected B \n";
echo "A::get_static() =========== " . get_class(A::get_static()) . " | expected A \n";
echo "\n";

echo "Object Calls on A: \n";
echo '$a->get_self() ============ ' . get_class($a->get_self()) .   " | expected A \n";
echo '$a->get_static() ========== ' . get_class($a->get_static()) . " | expected A \n";
echo "\n";

echo "Object Calls on B: \n";
echo '$b->get_self() ============ ' . get_class($b->get_self()) .   " | expected A \n";
echo '$b->get_static() ========== ' . get_class($b->get_static()) . " | expected B \n";
echo "\n";

echo "C Object Calls on A: \n";
echo "Internally against A::{call}\n";
echo '$c->static_get_a_self() === ' . get_class($c->static_get_a_self()) .   " | expected A \n";
echo '$c->static_get_a_static() = ' . get_class($c->static_get_a_static()) . " | expected A < Whoa! \n";
echo "Internally against \$a = new A();\n";
echo '$c->var_get_a_self() ====== ' . get_class($c->var_get_a_self()) .      " | expected A \n";
echo '$c->var_get_a_static() ==== ' . get_class($c->var_get_a_static()) .    " | expected A \n";
echo "\n";

echo "C Object Calls on B: \n";
echo "Internally against B::{call}\n";
echo '$c->static_get_b_self() === ' . get_class($c->static_get_b_self()) .   " | expected A \n";
echo '$c->static_get_b_static() = ' . get_class($c->static_get_b_static()) . " | expected B < Whoa! \n";
echo "Internally against \$b = new B();\n";
echo '$c->var_get_b_self() ====== ' . get_class($c->var_get_b_self()) .      " | expected A \n";
echo '$c->var_get_b_static() ==== ' . get_class($c->var_get_b_static()) .    " | expected B \n";
?>

结果:

Static calls: 
B::get_self() ============= A | expected A 
B::get_static() =========== B | expected B 
A::get_static() =========== A | expected A 

Object Calls on A: 
$a->get_self() ============ A | expected A 
$a->get_static() ========== A | expected A 

Object Calls on B: 
$b->get_self() ============ A | expected A 
$b->get_static() ========== B | expected B 

C Object Calls on A: 
Internally against A::{call}
$c->static_get_a_self() === A | expected A 
$c->static_get_a_static() = C | expected A < Whoa! 
Internally against $a = new A();
$c->var_get_a_self() ====== A | expected A 
$c->var_get_a_static() ==== A | expected A 

C Object Calls on B: 
Internally against B::{call}
$c->static_get_b_self() === A | expected A 
$c->static_get_b_static() = C | expected B < Whoa! 
Internally against $b = new B();
$c->var_get_b_self() ====== A | expected A 
$c->var_get_b_static() ==== B | expected B 

这种有意义,在Late Static Binding中,保留的'static'变量引用最后的Class范围。我正在寻找的是一个保留变量,它引用变量发生的顶级类。

IE:如果我使用名为Member的类扩展RecordObject类,我需要一个我可以在RecordObject中定义的函数,该函数将实例化一个新的Member(或Page或Comment),而不必在每个类定义中覆盖此函数。这可能吗?

我遇到的问题是,比如说,我在会员中,我调用了Page :: get($ id),它在内部创建了一个新的Object并且做了一些魔术。不幸的是,如果我使用静态,那个新对象就是会员......没有骰子。

1 个答案:

答案 0 :(得分:0)

你为什么忽略严格的错误?

只需将static关键字添加到静态方法。

class A {
static public function get_self() {
    return new self();
}

static public function get_static() {
    return new static();
}
}

一切都应该如预期的那样。

http://3v4l.org/RWRE9#v530