You can use this function to find common parent of multiple objects or classes.
<?php
/**
* Returns name of the first (in class hierarchy) common parent class of all provided objects or classes.
* Returns FALSE when common class is not found.
*
* @param mixed $objects Array that can contain objects or class names.
* @return mixed
*/
function get_first_common_parent($objects) {
$common_ancestors = null;
foreach($objects as $object) {
if (is_object($object)) {
$class_name = get_class($object);
} else {
$class_name = $object;
}
$parent_class_names = array();
$parent_class_name = $class_name;
do {
$parent_class_names[] = $parent_class_name;
} while($parent_class_name = get_parent_class($parent_class_name));
if ($common_ancestors === null) {
$common_ancestors = $parent_class_names;
} else {
$common_ancestors = array_intersect($common_ancestors, $parent_class_names);
}
}
return reset($common_ancestors);
}
?>
Example:
<?php
class A {
}
class B extends A {
}
class D extends B {
}
class E extends B {
}
class C extends A {
}
class F extends C {
}
class G extends F {
}
class H {
}
//returns "A"
get_first_common_parent(array('G', 'E'));
//returns "F"
get_first_common_parent(array(new G(), 'F'));
//returns false (no common parent)
get_first_common_parent(array('C', 'H'));
//returns false (non-existent class provided)
get_first_common_parent(array(new B(), 'X'));
?>
get_parent_class
(PHP 4, PHP 5)
get_parent_class — Pobiera nazwę klasy przodka dla obiektu lub klasy
Opis
Jeżeli obiekt jest obiektem, zwraca nazwę klasy
przodka klasy której obiekt jest egzemplarzem.
Jeżeli obiekt jest ciągiem znakowym, zwraca
nazwę klasy przodka klasy o tej nazwie. Ta funkcjonalność została dodana
w PHP 4.0.5.
Informacja:
Od PHP 5, argument
obiektjest opcjonalny, jeśli funkcja została wywołana z wnętrza metody obiektu. Jeśli zostanie wywołana bez argumentu spoza metody, zwrócona zostanie wartośćFALSE(lubNULLrazem z ostrzeżeniem w wersjach starszych niż PHP 5.1.0).
Przykład #1 Przykład użycia get_parent_class()
<?php
class tata {
function tata()
{
// implementacja jakiejś logiki...
}
}
class dziecko extends tata {
function dziecko()
{
echo "Moim prodkiem jest " , get_parent_class($this) , "\n";
}
}
class dziecko2 extends tata {
function dziecko2()
{
echo "Moim przodkiem także jest " , get_parent_class('dziecko2') , "\n";
}
}
$foo = new dzicko();
$bar = new dziecko2();
?>
Powyższy przykład wyświetli:
Moim przodkiem jest tata Moim przodkiem także jest tata
Patrz także: get_class(), is_subclass_of()
I have been playing with parent and child class, and I used this function to determine that which one was calling an function. I for an example it if you only want your parent class to be able to make an function call:
here is my example (by the way this example was inspired by another example fund on php.net):
<?php
class Parents {
public static $status; //This is the status
protected static $idCount;
protected $id;
function __construct() {
$this->id = ++self::$idCount;
self::$status = "tmp";
}
public function run($task) {
if(get_parent_class($this) == "") {
echo 'Command issued: '.$task.'<br>';
self::$status = $task;
}
}
public function __tostring() {
return "(".__class__.")id=".$this->id." status=".self::$status."<br>";
}
}
class Child extends Parents {
function __construct() {
parent::__construct();
self::$status = "tmp";
echo "Child construct<br>";
}
public function __tostring() {
return "(".__class__.")id=".$this->id." status=".self::$status."<br>";
}
}
$parent = new Parents();
echo $parent;
$child = new Child();
echo $child;
echo get_parent_class('Child')."<br>";
$parent->run("mtk");
echo $parent;
echo $child;
$child->run("mtk1");
echo $parent;
echo $child;
?>
which will produces somethink like:
(Parents)id=1 status=tmp
Child construct
(Child)id=2 status=tmp
Parents
Command issued: mtk
(Parents)id=1 status=mtk
(Child)id=2 status=mtk
(Parents)id=1 status=mtk
(Child)id=2 status=mtk
hopes it helps some one :D
I wrote a simple function doing the reverse thing: get the children:
<?php
function get_child($instance, $classname) {
$class = $classname;
$t = get_class($instance);
while (($p = get_parent_class($t)) !== false) {
if ($p == $class) {
return $t;
}
$t = $p;
}
return false;
}
abstract class A {
function someFunction() {
return get_child($this, __CLASS__);
}
}
class B extends A {
}
class C extends B {
}
$c = new C();
echo $c->someFunction(); //displays B
?>
This little snippet to get the inheritance tree might be useful to someone.
<?php
header("Content-Type: text/plain;");
class Top {
public function getParents($class=null, $plist=array()) {
$class = $class ? $class : $this;
$parent = get_parent_class($class);
if($parent) {
$plist[] = $parent;
/*Do not use $this. Use 'self' here instead, or you
* will get an infinite loop. */
$plist = self::getParents($parent, $plist);
}
return $plist;
}
}
class Middle extends Top {
}
class Bottom extends Middle {
}
$o = new Bottom();
print_r($o->getParents());
?>
"'If called without parameter outside object' What on earth does that mean?"
There are two places this could be called:
1. From within a member function of an object. In this case, it may be called with no parameters and will return the parent class of the object owning the member function. (If the parameter is included, then it will return the parent class of the specified class as normal.)
2. From outside an object (i.e., global or function scope). In this case, PHP doesn't know what class you're talking about if you don't include a parameter, so it returns FALSE. (But, of course, it works if you specify the class with the parameter.)
"If called without parameter outside object" What on earth does that mean?
What I can tell you, and that is not documented, is that if the object in question does not have an explicitly declared parent class, it does return boolean false. It doesn't for example return 'stdClass' on the basis that all objects are derived from that.
tim at correctclick dot com wrote:
<quote>
A slightly more cryptic but faster get_ancestors function:
<?php
function get_ancestors ($class) {
for ($classes[] = $class; $class = get_parent_class ($class); $classes[] = $class);
return $classes;
}
?>
(The second part of the for is implicitly testing for $class != ""). Recursion is considerably slower than looping, so you probably want to use this function.
Hope someone finds it useful.
</quote>
I would prefer this version, because it will create no duplicates:
<?php
function get_ancestors ($class) {
$classes = array($class);
while($class = get_parent_class($class)) { $classes[] = $class; }
return $classes;
}
Greets, Dennis
?>
PHP (4 at least, dunno about 5) stores classnames in lower case, so:
<?PHP
class Foo
{
}
class Bar extends Foo
{
}
echo get_parent_class('Bar');
echo "\n";
echo get_parent_class('bar');
?>
will output:
foo
foo
If the argument obj is a string and the class is not defined, then the function returns FALSE.
If the argument obj is an object created from a class with no ancestors (or a string representing a class with no ancestors), then the function returns FALSE.
A slightly more cryptic but faster get_ancestors function:
function get_ancestors ($class) {
for ($classes[] = $class; $class = get_parent_class ($class); $classes[] = $class);
return $classes;
}
(The second part of the for is implicitly testing for $class != ""). Recursion is considerably slower than looping, so you probably want to use this function.
Hope someone finds it useful.
To return all ancestors class of an object
function get_ancestors_class($classname) {
$father = get_parent_class($classname);
if ($father != "") {
$ancestors = get_ancestors_class($father);
$ancestors[] = $father;
}
return $ancestors;
}
example :
-----------
Class C {
}
Class B extends C {
}
Class A extends B {
}
print_r (get_ancestors_class("a"));
print_r (get_ancestors_class("b"));
example result :
---------------
Array
(
[0] => c
[1] => b
)
Array
(
[0] => c
)
