Closure::bind
(PHP 5 >= 5.4.0)
Closure::bind — Duplicates a closure with a specific bound object and class scope
Description
$closure
, object $newthis
[, mixed $newscope
= "static"
] )This method is a static version of Closure::bindTo(). See the documentation of that method for more information.
Parameters
-
closure -
The anonymous functions to bind.
-
newthis -
The object to which the given anonymous function should be bound, or
NULLfor the closure to be unbound. -
newscope -
The class scope to which associate the closure is to be associated, or 'static' to keep the current one. If an object is given, the type of the object will be used instead. This determines the visibility of protected and private methods of the bound object.
Return Values
Returns a new Closure object or FALSE on failure
Examples
Example #1 Closure::bind() example
<?php
class A {
private static $sfoo = 1;
private $ifoo = 2;
}
$cl1 = static function() {
return A::$sfoo;
};
$cl2 = function() {
return $this->ifoo;
};
$bcl1 = Closure::bind($cl1, null, 'A');
$bcl2 = Closure::bind($cl2, new A(), 'A');
echo $bcl1(), "\n";
echo $bcl2(), "\n";
?>
The above example will output something similar to:
1 2
See Also
- Anonymous functions
- Closure::bindTo() - Duplicates the closure with a new bound object and class scope
- PHP Руководство
- Функции по категориям
- Индекс функций
- Справочник языка
- Встроенные интерфейсы и классы
- Функция Closure::__construct() - Конструктор запрещающий создавать новые объекты
- Функция Closure::bind() - Дублирует замыкание с указанием связанного объекта и области видимости класса
- Функция Closure::bindTo() - Дублирует замыкание с указанием связанного объекта и области видимости класса
- Closure::call
Коментарии
With this class and method, it's possible to do nice things, like add methods on the fly to an object.
MetaTrait.php
<?php
trait MetaTrait
{
private $methods = array();
public function addMethod($methodName, $methodCallable)
{
if (!is_callable($methodCallable)) {
throw new InvalidArgumentException('Second param must be callable');
}
$this->methods[$methodName] = Closure::bind($methodCallable, $this, get_class());
}
public function __call($methodName, array $args)
{
if (isset($this->methods[$methodName])) {
return call_user_func_array($this->methods[$methodName], $args);
}
throw RunTimeException('There is no method with the given name to call');
}
}
?>
test.php
<?php
require 'MetaTrait.php';
class HackThursday {
use MetaTrait;
private $dayOfWeek = 'Thursday';
}
$test = new HackThursday();
$test->addMethod('when', function () {
return $this->dayOfWeek;
});
echo $test->when();
?>
If you need to validate whether or not a closure can be bound to a PHP object, you will have to resort to using reflection.
<?php
/**
* @param \Closure $callable
*
* @return bool
*/
function isBindable(\Closure $callable)
{
$bindable = false;
$reflectionFunction = new \ReflectionFunction($callable);
if (
$reflectionFunction->getClosureScopeClass() === null
|| $reflectionFunction->getClosureThis() !== null
) {
$bindable = true;
}
return $bindable;
}
?>