Diese Seite bei php.net
The PHP manual text and comments are covered by the Creative Commons Attribution 3.0 License © the PHP Documentation Group - Impressum - mail("TO:Reinhard Neidl",...)
(PHP 5 >= 5.3.0)
get_called_class — the "Late Static Binding" class name
Gets the name of the class the static method is called in.
Returns the class name. Returns FALSE if called from outside a class.
Beispiel #1 Using get_called_class()
<?php
class foo {
static public function test() {
var_dump(get_called_class());
}
}
class bar extends foo {
}
foo::test();
bar::test();
?>
Das oben gezeigte Beispiel erzeugt folgende Ausgabe:
string(3) "foo" string(3) "bar"
if you cannot avoid that carriage return characters will be used as windows linebreaks, you should set
<?php ini_set("auto_detect_line_endings", 1); ?>
otherwise the solutions posted here will fail.
Beware that this does not behave as expected if your method is not declared as static! For example:
<?php
class foo {
static public function test() {
var_dump(get_called_class());
}
public function testTwo() {
var_dump(get_called_class());
}
}
class bar extends foo {
}
class abc {
function test() {
foo::test();
bar::test();
}
function testTwo() {
foo::testTwo();
bar::testTwo();
}
}
echo "basic\n";
foo::test();
bar::test();
echo "basic without static declaration\n";
foo::testTwo();
bar::testTwo();
echo "in a class\n";
$abc = new abc();
$abc->test();
echo "in a class without static declaration\n";
$abc->testTwo();
?>
The result is:
basic
string 'foo'
string 'bar'
basic without static declaration
string 'foo'
string 'bar'
in a class
string 'foo'
string 'bar'
in a class without static declaration
string 'abc'
string 'abc'
I've made some additions to mucahitkahveci's method, but ended up re-writing it to suit certain needs and conventions.
It passes the example test cases on the late static bindings page with the <?php static::funtion_name() ?> calls converted to
<?php
$static_class = get_called_class();
call_user_func(array($static_class,'function_name'));
?>
I tested it in PHP 5.2.4 and came across no discrepancies from the 5.3 behavior, however the more eyes the better.
Also, I've included the edge case where a static property can be called on a class e.g.
<?php
class A {
public function __get($var) {
return get_class_name();
}
}
$instance = new A();
echo $instance->foo;
?>
However this probably doesn't cover all edge cases, so the function still needs work.
And here it is...
<?php
/********************************
* Retro-support of get_called_class()
* Tested and works in PHP 5.2.4
* http://www.sol1.com.au/
********************************/
if(!function_exists('get_called_class')) {
function get_called_class($bt = false,$l = 1) {
if (!$bt) $bt = debug_backtrace();
if (!isset($bt[$l])) throw new Exception("Cannot find called class -> stack level too deep.");
if (!isset($bt[$l]['type'])) {
throw new Exception ('type not set');
}
else switch ($bt[$l]['type']) {
case '::':
$lines = file($bt[$l]['file']);
$i = 0;
$callerLine = '';
do {
$i++;
$callerLine = $lines[$bt[$l]['line']-$i] . $callerLine;
} while (stripos($callerLine,$bt[$l]['function']) === false);
preg_match('/([a-zA-Z0-9\_]+)::'.$bt[$l]['function'].'/',
$callerLine,
$matches);
if (!isset($matches[1])) {
// must be an edge case.
throw new Exception ("Could not find caller class: originating method call is obscured.");
}
switch ($matches[1]) {
case 'self':
case 'parent':
return get_called_class($bt,$l+1);
default:
return $matches[1];
}
// won't get here.
case '->': switch ($bt[$l]['function']) {
case '__get':
// edge case -> get class of calling object
if (!is_object($bt[$l]['object'])) throw new Exception ("Edge case fail. __get called on non object.");
return get_class($bt[$l]['object']);
default: return $bt[$l]['class'];
}
default: throw new Exception ("Unknown backtrace method type");
}
}
}
?>
[EDIT BY danbrown AT php DOT net: Contains a fix provided by (webmaster AT easy DASH coding DOT de) on 10-NOV-09 with the following explanation: since method calls are caseinsensitive you should use stripos instead of strpos. Otherwise you will end up with a "Undefined offset: -1" notice and the error "Could not find caller class."]
Addition to tom at r dot je:
It is fine but does not work for method calls like:
<?php
class Car
{
static function getClass()
{
echo get_called_class();
}
}
$method='getClass';
Car::$method(); //prints nothing
?>
So I developed to meet also this issue, and add one extra line not to cause notice errors:
<?php
if(!function_exists('get_called_class')) {
function get_called_class() {
$matches=array();
$bt = debug_backtrace();
$l = 0;
do {
$l++;
if(isset($bt[$l]['class']) AND !empty($bt[$l]['class'])) {
return $bt[$l]['class'];
}
$lines = file($bt[$l]['file']);
$callerLine = $lines[$bt[$l]['line']-1];
preg_match('/([a-zA-Z0-9\_]+)::'.$bt[$l]['function'].'/',
$callerLine,
$matches);
if (!isset($matches[1])) $matches[1]=NULL; //for notices
if ($matches[1] == 'self') {
$line = $bt[$l]['line']-1;
while ($line > 0 && strpos($lines[$line], 'class') === false) {
$line--;
}
preg_match('/class[\s]+(.+?)[\s]+/si', $lines[$line], $matches);
}
}
while ($matches[1] == 'parent' && $matches[1]);
return $matches[1];
}
}
?>
I've further extended spidgorny at gmail dot com's 5.2 get_called_class() solution to also account for self:: calls. It works backwards up the file to find the class definition.
<?php
if(!function_exists('get_called_class')) {
function get_called_class() {
$bt = debug_backtrace();
$l = 0;
do {
$l++;
$lines = file($bt[$l]['file']);
$callerLine = $lines[$bt[$l]['line']-1];
preg_match('/([a-zA-Z0-9\_]+)::'.$bt[$l]['function'].'/',
$callerLine,
$matches);
if ($matches[1] == 'self') {
$line = $bt[$l]['line']-1;
while ($line > 0 && strpos($lines[$line], 'class') === false) {
$line--;
}
preg_match('/class[\s]+(.+?)[\s]+/si', $lines[$line], $matches);
}
}
while ($matches[1] == 'parent' && $matches[1]);
return $matches[1];
}
}
?>
Not pretty but works until servers can be upgraded.
If you call a static getInstance() function to create a instance of a class from another class, this function have to be static, if it is not static the original name of the caller class and not of the current class get returned.
example:
<?php
class a {
function getXName() {
return x::getClassName();
}
function getXStaticName() {
return x::getStaticClassName();
}
}
class b extends a {
}
class x {
public function getClassName() {
return get_called_class();
}
public static function getStaticClassName() {
return get_called_class();
}
}
$a = new a();
$b = new b();
echo $a->getXName(); // will return "a"
echo $b->getXName(); // will return "b"
echo $a->getXStaticName(); // will return "x"
echo $b->getXStaticName(); // will return "x"
?>
I've furthered enhanced the attempts to fix get_called_class() for PHP 5.2 Using a class and some static properties, we can keep track of how many times it has already processed the current line, so multiple calls on the same line will still function properly.
<?php
if(!function_exists('get_called_class')) {
class class_tools {
static $i = 0;
static $fl = null;
static function get_called() {
$bt = debug_backtrace();
if(self::$fl == $bt[2]['file'].$bt[2]['line']) {
self::$i++;
} else {
self::$i = 0;
self::$fl = $bt[2]['file'].$bt[2]['line'];
}
$lines = file($bt[2]['file']);
preg_match_all('/([a-zA-Z0-9\_]+)::'.$bt[2]['function'].'/',
$lines[$bt[2]['line']-1],
$matches);
return $matches[1][self::$i];
}
}
function get_called_class() {
return class_tools::get_called_class();
}
}
?>
Small change to spidgorny at gmail dot com's example so that it works with static calls as well.
Change:
} while ($matches[1] == 'parent' && $matches[1]);
to:
} while( in_array($matches[1], array('parent', 'self')) && $matches[1]);
My modification to the get_called_class() simulation function, which takes care of the parent:: calls. It goes further into the backtrace to find the first non "parent" call. This way we pop-up to the original caller class. I'm not sure if this is the default behavior of the original PHP 5.3 function.
<?php
// http://us.php.net/manual/en/function.get-called-class.php#89478
if (!function_exists('get_called_class')):
function get_called_class() {
$bt = debug_backtrace();
//debug($bt);
$l = 0;
do {
$l++;
$lines = file($bt[$l]['file']);
$callerLine = $lines[$bt[$l]['line']-1];
//debug($callerLine);
preg_match('/([a-zA-Z0-9\_]+)::'.$bt[$l]['function'].'/',
$callerLine,
$matches);
} while ($matches[1] == 'parent' && $matches[1]);
return $matches[1];
}
endif;
?>
Simplified version:
<?php if (!function_exists('get_called_class')):
function get_called_class()
{
$bt = debug_backtrace();
$lines = file($bt[1]['file']);
preg_match('/([a-zA-Z0-9\_]+)::'.$bt[1]['function'].'/',
$lines[$bt[1]['line']-1],
$matches);
return $matches[1];
}
endif; ?>
When you use this function in singleton, mind there can by only one getInstance() call per line:
<?php
abstract class Singleton { ... }
class MySingleton1 extends Singleton { ... }
class MySingleton2 extends Singleton { ... }
// this will work:
$s1 = MySingleton1::getInstance();
$s2 = MySingleton2::getInstance();
// here will be problem:
$s1 = MySingleton1::getInstance(); $s2 = MySingleton2::getInstance();
?>
Here's a simple way of getting the inheritance tree of a class, no matter which class the function was actually defined in. Will work as a static function method too.
<?php
class A {
public function get_class_tree(){
$cur_class = get_called_class();
do {
echo $cur_class;
}
while($cur_class = get_parent_class($cur_class));
}
}
class B {
}
class C {
}
$foo = new C();
$foo->get_class_tree();
?>
CBA
It is possible to write a completely self-contained Singleton base class in PHP 5.3 using get_called_class.
<?php
abstract class Singleton {
protected function __construct() {
}
final public static function getInstance() {
static $aoInstance = array();
$calledClassName = get_called_class();
if (! isset ($aoInstance[$calledClassName])) {
$aoInstance[$calledClassName] = new $calledClassName();
}
return $aoInstance[$calledClassName];
}
final private function __clone() {
}
}
class DatabaseConnection extends Singleton {
protected $connection;
protected function __construct() {
// @todo Connect to the database
}
public function __destruct() {
// @todo Drop the connection to the database
}
}
$oDbConn = new DatabaseConnection(); // Fatal error
$oDbConn = DatabaseConnection::getInstance(); // Returns single instance
?>
Full write-up in Oct 2008: http://danbettles.blogspot.com
Diese Seite bei php.net