Function visibility (in PHP5) has some quirks as compared to the normal behavior with "extends". Consider the following:
<?php
class base {
public function a() { $this->b(); }
private function b() { echo "This is b()"; }
}
?>
This will work fine:
<?php
class inherit extends base {
public function c() { $this->a(); }
}
$x = new inherit;
$x->c();
?>
while this:
<?php
class adopt {
public function c() { $this->a(); }
}
runkit_class_adopt('adopt','base');
$x = new adopt;
$x->c();
?>
will generate a fatal "Call to private method base::b() from context 'adopt'" error. Protected members can be called from the inherited methods, but still cannot be called from the original class (i.e. if b() were declared protected, the example would work as written, but adopt::c() still could not call base::b() directly.
Functions such as is_subclass_of(), is_a(), and the instanceof operator also do not detect the new lineage of the object; if you are using this function to simulate multiple or dynamic inheritance, you may need to implement your own method of determining class lineage.
[EDIT by danbrown AT php DOT net: Merged addendum to post by original author.]
runkit_class_adopt
(PECL runkit >= 0.7.0)
runkit_class_adopt — ある基底クラスを、他のクラスを継承させたクラスに変換する。親クラスの適切なメソッドを追加する
説明
bool runkit_class_adopt
( string $classname
, string $parentname
)
パラメータ
- classname
-
変換の対象となるクラス。
- parentname
-
継承させる親クラス。
返り値
成功した場合に TRUE を、失敗した場合に FALSE を返します。
例
例1 runkit_class_adopt() の例
<?php
class myParent {
function parentFunc() {
echo "Parent Function Output\n";
}
}
class myChild {
}
runkit_class_adopt('myChild','myParent');
myChild::parentFunc();
?>
上の例の出力は以下となります。
Parent Function Output
runkit_class_adopt
muramas at cyberdiscordia dot org
02-Sep-2005 10:09
02-Sep-2005 10:09
