forward_static_call
(PHP 5 >= 5.3.0)
forward_static_call — Call a static method
Description
Calls a user defined function or method given by the function
parameter, with the following arguments. This function must be called within a method
context, it can't be used outside a class.
It uses the late static
binding.
Parameters
-
function -
The function or method to be called. This parameter may be an array, with the name of the class, and the method, or a string, with a function name.
-
parameter -
Zero or more parameters to be passed to the function.
Return Values
Returns the function result, or FALSE on error.
Examples
Example #1 forward_static_call() example
<?php
class A
{
const NAME = 'A';
public static function test() {
$args = func_get_args();
echo static::NAME, " ".join(',', $args)." \n";
}
}
class B extends A
{
const NAME = 'B';
public static function test() {
echo self::NAME, "\n";
forward_static_call(array('A', 'test'), 'more', 'args');
forward_static_call( 'test', 'other', 'args');
}
}
B::test('foo');
function test() {
$args = func_get_args();
echo "C ".join(',', $args)." \n";
}
?>
The above example will output:
B B more,args C other,args
See Also
- forward_static_call_array() - Call a static method and pass the arguments as array
- call_user_func_array() - Call a callback with an array of parameters
- call_user_func() - Call the callback given by the first parameter
- is_callable() - Verify that the contents of a variable can be called as a function
- information about the callback type
Коментарии
Example to understand this function and difference with call_user_func:
<?php
class Beer {
const NAME = 'Beer!';
public static function printed(){
echo 'static Beer:NAME = '. static::NAME . PHP_EOL;
}
}
class Ale extends Beer {
const NAME = 'Ale!';
public static function printed(){
forward_static_call(array('parent','printed'));
call_user_func(array('parent','printed'));
forward_static_call(array('Beer','printed'));
call_user_func(array('Beer','printed'));
}
}
Ale::printed();
echo '</pre>';
?>
Example usage via calls outside of the class and within an object:
<?php
/**
* @author Jonathon Hibbard
*/
class foo {
# used to verify we're actually setting something..
private static $value = '';
/**
* Simple setter for the static method setValue...
*/
public static function set($method_identifier, $value_to_pass = '') {
# make sure we have the right method format...
# another semi-useful example is like this (useful for REST-like requests...): str_replace(" ", "", ucwords(str_replace("_", " ", $method_identifier)));
$static_method = 'set' . ucfirst(strtolower(trim($method_identifier)));
if(method_exists(__CLASS__, $static_method)) {
//Note: this will not work and will throw PHP Parse error: syntax error, unexpected '::'
//__CLASS__::$static_method($value_to_pass);
foo::$static_method($value_to_pass);
echo "\tCalling forward_static_call with pure string and value param:\n";
forward_static_call(__CLASS__ . "::" . $static_method, $value_to_pass);
echo "\tCalling forward_static_call with class, method array and value param:\n";
forward_static_call(array(__CLASS__, $static_method), $value_to_pass);
}
}
/**
* Set self::$value to something?
*/
public static function setValue($value_recieved = '') {
echo "\t\tsetValue called with param of " . var_export($value_recieved, true) . "!\n";
echo "\t\tSetting Private 'value'...\n";
self::$value = $value_recieved;
echo "\t\tChecking the Private 'value':\n";
if(!empty(self::$value)) {
echo "\t\t\tPrivate 'value' was set to '" . self::$value . "' as expected!\n";
} else {
echo "\t\t\tPrivate 'value' was not set!\n";
}
# Reset...
self::$value = '';
}
/**
* Create an object and test calling the static method from within this realm...
*/
public function __construct() {
echo "\tCalling from within constructor..\n";
foo::set('value','Something else from within the instance!');
}
}
echo "\n============ Calling by static method first ============\n";
foo::set('value','Something from outside of the foo class!');
echo "\n============ Calling by static method without a value next ============\n";
foo::set('value');
echo "\n============ Calling by createing an instance next ============\n";
new foo();
?>