Closure::bind
(PHP 5 >= 5.4.0, PHP 7, PHP 8)
Closure::bind — 复制一个闭包，绑定指定的$this对象和类作用域。
说明
public static Closure::bind(Closure
$closure, ?object $newThis, object|string|null $newScope = "static"): ?Closure这个方法是 Closure::bindTo() 的静态版本。查看它的文档获取更多信息。
参数
-
closure -
需要绑定的匿名函数。
-
newThis -
需要绑定到匿名函数的对象，或者
null创建未绑定的闭包。 -
newScope -
想要绑定给闭包的类作用域，或者 'static' 表示不改变。如果传入一个对象，则使用这个对象的类型名。 类作用域用来决定在闭包中 $this 对象的 私有、保护方法 的可见性。 不允许内置类（的对象）作为参数传递。
返回值
返回一个新的 Closure 对象，失败时返回 null。
范例
示例 #1 Closure::bind() 示例
<?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 $bcl2(), "\n";
?>
以上例程的输出类似于：
1 2
参见
- 匿名函数
- Closure::bindTo() - 复制当前闭包对象，绑定指定的$this对象和类作用域。
add a note
User Contributed Notes 2 notes
Vincius Krolow ¶
9 years ago
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();
?>
potherca at hotmail dot com ¶
7 years ago
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;
}
?>