在PHP闭包中注入代码 [英] Inject code in a PHP closure

问题描述

我有一个已经定义的闭包，我想在我执行它时注入代码。
这里是一个例子：

I have an already defined closure and I want to inject code inside when I execute it. Here is an example:

$predefined = "print 'my predefined injected code<br />';";
$closure = function () {
  print 'hello<br />';
};
call_user_func_array($closure, array());
// output : hello

我想混合2个代码：闭合的一个。
修改后，我希望我的关闭看起来像这样

I want to mix 2 codes : a predefined one and the closure's one. After modification, I want my closure to look like this

$closure = function () {
  print 'my predefined injected code<br />';
  print 'hello<br />';
};

是否可以在执行之前在闭包中插入一些代码？

Is it possible to insert some code in the closure before executing it ?

注意：我不能使用create_function将代码作为字符串，所以可以很容易地修改。闭包已经定义并以某种方式定义（通过接受回调arg，而不是字符串arg的函数）。

Note: I can not use "create_function" that take the code as a string, so can be modified easily. The closures are already defined and are defined in a certain way (through a function that take a callback arg, not a string arg).

感谢您的帮助。

编辑：

>

Here is the solution

function hackClosure($closure, $inject_code)
{
    $reflection = new ReflectionFunction($closure);
    $tmp = $reflection->getParameters();
    $args = array();
    foreach ($tmp as $a) array_push($args, '$'.$a->getName() . ($a->isDefaultValueAvailable() ? '=\''.$a->getDefaultValue().'\'' : ''));
    $file = new SplFileObject($reflection->getFileName());
    $file->seek($reflection->getStartLine()-1);
    $code = '';
    while ($file->key() < $reflection->getEndLine())
    {
        $code .= $file->current();
        $file->next();
    }
    $start = strpos($code, '{')+1;
    $end = strrpos($code, '}');
    return create_function(implode(', ', $args), substr($code, $start, $end - $start) . $inject_code);
}

$theClosure = function () { print 'something'; };

$inject_code = "print ' to say';";

$func = hackClosure($theClosure, $inject_code);
$func();

它呈现

something to say

而不是

something

推荐答案

您不能直接注入它。

$newClosure = function() use ($closure) {
    print 'my predefined injected code<br />';
    $closure();
};

此外，也不需要使用 call_user_func_array 因为你没有传递任何参数。只需调用 $ closure（）;

Also, there's no need to use call_user_func_array since you're not passing any arguments. Just call $closure();

同样，你可以构建一个包装器来获得一个新的闭包： p>

Also, you could build a wrapper to get a new closure:

$creator = function($closure) {
    return function() use ($closure) {
        print 'my predefined injected code<br />';
        $closure();
    };
};

$newClosure = $creator($closure);
$newClosure();

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