PHP 8.1.0 RC 2 available for testing

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。 It is not allowed to pass (an object of) an internal class as this parameter.

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 {
    private static 
$sfoo 1;
    private 
$ifoo 2;
}
$cl1 = static function() {
    return 
A::$sfoo;
};
$cl2 = function() {
    return 
$this->ifoo;
};

$bcl1 Closure::bind($cl1null'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

add a note add a note

User Contributed Notes 2 notes

up
94
Vincius Krolow
8 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();

?>
up
5
potherca at hotmail dot com
6 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;
}
?>
To Top