在 PHP 闭包中注入代码

发布于 2024-10-19 14:06:09 字数 1630 浏览 0 评论 0原文

我有一个已经定义的闭包，我想在执行它时在其中注入代码。这是一个示例：

$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：预定义的代码和闭包的代码。修改后，我希望我的闭包看起来像这样

$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？

注意：我不能使用将代码作为字符串的“create_function”，因此可以轻松修改。闭包已经定义并且以某种方式定义（通过采用回调参数而不是字符串参数的函数）。

感谢您的帮助。

编辑：

解决方案

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();

这是它呈现的

something to say

而不是

something

原文

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

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 />';
};

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

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).

Thanks for your help.

EDIT:

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, '
It renders 
something to say

instead of
something

.$a->getName() . ($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();

It renders

instead of

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篱下浅笙歌 2024-10-26 14:06:10

你不能直接注入它。但是，您可以将其包裹起来。

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

此外，无需使用 call_user_func_array 因为您没有传递任何参数。只需调用 $closure();

另外，您可以构建一个包装器来获取新的闭包：

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

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

You can't directly inject it. However, you can wrap it.

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

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

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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几味少女 2024-10-26 14:06:10

也许是这样的：

$closure = function($optionalcode = null) {
    print('blah blah blah');
    if (!is_null($optionalcode)) { eval($optionalcode); }
    print('blah blah blah');
}

$closure("print('yoohoo!');");

然而，eval()是邪恶的，应该不惜一切代价避免。

perhaps something like this:

$closure = function($optionalcode = null) {
    print('blah blah blah');
    if (!is_null($optionalcode)) { eval($optionalcode); }
    print('blah blah blah');
}

$closure("print('yoohoo!');");

However, eval() is evil and should be avoided at all costs.

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