(PECL runkit >= 0.7.0)
runkit_class_adopt — Convert a base class to an inherited class, add ancestral methods when appropriate
$classname
, string $parentname
)
classname
Name of class to be adopted
parentname
Parent class which child class is extending
成功时返回 TRUE， 或者在失败时返回 FALSE。
Example #1 A runkit_class_adopt() example
<?php
class myParent {
function parentFunc() {
echo "Parent Function Output\n";
}
}
class myChild {
}
runkit_class_adopt('myChild','myParent');
myChild::parentFunc();
?>
以上例程会输出：
Parent Function Output
muramas at cyberdiscordia dot org (2005-09-02 15:09:45)
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.]