Suppose I have a static callable like \Foo::bar.

I can assign this to a variable like this and then call it:

$myCallable = \Foo::class . '::bar';
// This works.
$myCallable('calling this works!');

But if I assign it to a static class property like this:

class MyClass {

  function myFunc() {
    static::$myCallable = \Foo::class . '::bar';

    static::$myCallable('this does not work');
  }

}

it fails, because it tries to call MyClass::Foo::bar().

Is there a way to fix this, other than using call_user_func()?

Suppose I have a static callable like \Foo::bar.

I can assign this to a variable like this and then call it:

$myCallable = \Foo::class . '::bar';
// This works.
$myCallable('calling this works!');

But if I assign it to a static class property like this:

class MyClass {

  function myFunc() {
    static::$myCallable = \Foo::class . '::bar';

    static::$myCallable('this does not work');
  }

}

it fails, because it tries to call MyClass::Foo::bar().

Is there a way to fix this, other than using call_user_func()?

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Share Follow edited Mar 8 at 0:39 Dharman♦ 33.5k2727 gold badges101101 silver badges149149 bronze badges Recognized by PHP Collective asked Mar 7 at 14:53 joachimjoachim 31k1313 gold badges4545 silver badges5050 bronze badges

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2 Answers 2

Sorted by: Reset to default 2

It isn't mentioned in the Operator Precedence documentation but :: seems to have lower precedence than function parenthesis. This should work:

(self::$myCallable)('this also works');

Full example:

class Foo
{
    public static function bar(string $label): void
    {
        echo "Callable called: $label\n";
    }
}

class MyClass
{
    private static string $myCallable;

    public function myFunc(): void
    {
        static::$myCallable = \Foo::class . '::bar';
        (self::$myCallable)('this also works');
    }
}

$myCallable = \Foo::class . '::bar';
$myCallable('calling this works!');

(new MyClass)->myFunc();

Demo

$myCallable('calling this works!');
^^^^^^^^^^^.. defined variable

now for your static:: invocation:

static::$myCallable('this does not work');
        ^^^^^^^^^^^.. undefined variable


(static::$myCallable)('this does work');
 ^^^^^^^^^^^^^^^^^^^.. defined static property

(static::$myCallable)(...)('this does work');

...

As you can see, it works the same, but you need a defined variable/property.