When calling dynamic method statically in php 5.6 (under 7) it allows it, but it doesnt work, it incorrectly evaluates class that called our subject class, therefore containing method must be static.
(PHP 5 >= 5.3.0, PHP 7)
get_called_class — 后期静态绑定（"Late Static Binding"）类的名称
获取静态方法调用的类名。
返回类的名称，如果不是在类中调用则返回 FALSE。
Example #1 get_called_class() 的使用
<?php
class foo {
static public function test() {
var_dump(get_called_class());
}
}
class bar extends foo {
}
foo::test();
bar::test();
?>
以上例程会输出：
string(3) "foo" string(3) "bar"
When calling dynamic method statically in php 5.6 (under 7) it allows it, but it doesnt work, it incorrectly evaluates class that called our subject class, therefore containing method must be static.
As of PHP 5.5 you can also use "static::class" to get the name of the called class.
<?php
class Bar {
public static function test() {
var_dump(static::class);
}
}
class Foo extends Bar {
}
Foo::test();
Bar::test();
?>
Output:
string(3) "Foo"
string(3) "Bar"
get_called_class() in closure-scopes:
<?PHP
ABSTRACT CLASS Base
{
protected static $stub = ['baz'];
//final public function boot()
static public function boot()
{
print __METHOD__.'-> '.get_called_class().PHP_EOL;
array_walk(static::$stub, function()
{
print __METHOD__.'-> '.get_called_class().PHP_EOL;
});
}
public function __construct()
{
self::boot();
print __METHOD__.'-> '.get_called_class().PHP_EOL;
array_walk(static::$stub, function()
{
print __METHOD__.'-> '.get_called_class().PHP_EOL;
});
}
}
CLASS Sub EXTENDS Base
{
}
// static boot
Base::boot(); print PHP_EOL;
// Base::boot -> Base
// Base::{closure} -> Base
Sub::boot(); print PHP_EOL;
// Base::boot -> Sub
// Base::{closure} -> Base
new sub;
// Base::boot -> Sub
// Base::{closure} -> Base
// Base->__construct -> Sub
// Base->{closure} -> Sub
// instance boot
new sub;
// Base->boot -> Sub
// Base->{closure} -> Sub
// Base->__construct -> Sub
// Base->{closure} -> Sub
?>
SEE: http://php.net/manual/en/language.oop5.late-static-bindings.php
I think it is worth mentioning on this page, that many uses of the value returned by get_called_function() could be handled with the new use of the old keyword static, as in
<?php
static::$foo;
?>
versus
<?php
$that=get_called_class();
$that::$foo;
?>
I had been using $that:: as my conventional replacement for self:: until my googling landed me the url above. I have replaced all uses of $that with static with success both as
<?php
static::$foo; //and...
new static();
?>
Since static:: is listed with the limitation: "Another difference is that static:: can only refer to static properties." one may still need to use a $that:: to call static functions; though I have not yet needed this semantic.
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'
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"
?>
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
?>