forward_static_call()
(PHP 5 >= 5.3.0, PHP 7)
Call a static method
说明
forward_static_call(callable $function[,mixed $parameter[,mixed$...
]]): mixed
Calls a user defined function or method given by the$functionparameter, with the following arguments. This function must be called within a method context, it can't be used outside a class. It uses thelate static binding.
参数
- $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.
返回值
Returns the function result,orFALSE
on error.
范例
Example #1forward_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"; } ?>
以上例程会输出:
B B more,args C other,args
参见
forward_static_call_array()
Call a static method and pass the arguments as arraycall_user_func_array()
调用回调函数,并把一个数组参数作为回调函数的参数call_user_func()
把第一个参数作为回调函数调用is_callable()
检测参数是否为合法的可调用结构- callback类型的信息
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(); ?>