Get PHP callable arguments as an array?

Question

Say I have a callable stored as a variable:

$callable = function($foo = 'bar', $baz = ...) { return...; }

How would I get 'bar'?

if (is_callable($callable)) {
  return func_get_args();
}

Unfortunately func_get_args() is for the current function, is it possible to get a key value pair of arguments?

score 5 · Accepted Answer · answered Jan 26 '15 at 11:31

5

You can use reflection:

$f = new ReflectionFunction($callable);
$params = $f->getParameters();
echo $params[0]->getDefaultValue();

answered Jan 26 '15 at 11:31

Marek

7,337
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Will `ReflectionFunction` work for any callable? (like class methods and static methods?) – SparK Apr 20 '17 at 00:15
1

@SparK No, it will not work. This was my case. You can take a look at my answer if you still need this. – miile7 Jun 08 '18 at 08:40

score 1 · Answer 2 · answered Jan 26 '15 at 11:22

1

You may want to use get_defined_vars to accomplish this, this function will return an array of all defined variables, specifically by accessing the callable index from the output array.

answered Jan 26 '15 at 11:22

Ma'moon Al-Akash

4,445
1
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miile7 · Answer 3 · 2018-06-08T09:06:12.037

I came across this question because I was looking for getting the arguments for a callable which is not just the function itself. My case is

class MyClass{
    public function f(){
        // do some stuff
    }
}

$myclass = new MyClass();
$callable = array($myclass, "f);

This is a valid callback in php. In this case the solution given by @Marek does not work.

I worked around with phps is_callable function. You can get the name of the function by using the third parameter. Then you have to check whether your callback is a function or a (class/object) method. Otherwise the Reflection-classes will mess up.

if($callable instanceof Closure){
    $name = "";
    is_callable($callable, false, $name);

    if(strpos($name, "::") !== false){
        $r = new ReflectionMethod($name);
    }
    else{
        $r = new ReflectionFunction($name);
    }
}
else{
    $r = new ReflectionFunction($callable);
}

$parameters = $r->getParameters();
// ...

This also returns the correct value for ReflectionFunctionAbstract::isStatic() even though the $name always uses :: which normally indicates a static function (with some exceptions).

Note: In PHP>=7.0 this may be easier using Closures. There you can do someting like

$closure = Closure::fromCallable($callable);

$r = new ReflectionFunction($closure);

You may also cause have to distinguish between ReflectionFunction and ReflectionMethod but I can't test this because I am not using PHP>=7.0.

Get PHP callable arguments as an array?

3 Answers3