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Subject: Re: [PHP-DEV] RFC Proposal : Allows calling non-static public methods
 through the __callStatic magic method instead of throwing an error.
In-Reply-To: <a8c25497-cd75-4270-8572-62ba28457f4d@app.fastmail.com>
Date: Sat, 17 Feb 2024 22:26:44 +0100
Cc: php internals <internals@lists.php.net>
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Message-ID: <D575F440-609E-4B6F-8D46-002FFA1D450A@gmail.com>
References: <CAKkgovSFUMwhdVERHHb-5Pw7Bm_hBcYbZqPH58JX1mvhW6d=rg@mail.gmail.com>
 <a8c25497-cd75-4270-8572-62ba28457f4d@app.fastmail.com>
To: Larry Garfield <larry@garfieldtech.com>
From: claude.pache@gmail.com (Claude Pache)



> Le 17 f=C3=A9vr. 2024 =C3=A0 16:51, Larry Garfield =
<larry@garfieldtech.com> a =C3=A9crit :
>=20
> On Fri, Feb 16, 2024, at 7:56 PM, =ED=95=98=EB=8A=98=EC=95=84=EB=B6=80=EC=
=A7=80 wrote:
>> Hi.
>> I'd like to propose an RFC, but I don't have the authority.
>> Below is my suggestion.
>> If you think this makes sense, please write an RFC for me.
>> Sincerely.
>>=20
>> ----------------------------------------------------------
>>=20
>> =3D=3D=3D=3D=3D Introduction =3D=3D=3D=3D=3D
>> Allows calling non-static public methods through the __callStatic =
magic=20
>> method instead of throwing an error.
>>=20
>> =3D=3D=3D=3D=3D Proposal =3D=3D=3D=3D=3D
>>=20
>> =46rom a conceptual perspective:
>> It goes without saying that calling a non-static method statically =
will=20
>> result in an error.
>> However, a confusing situation occurred when the __callStatic magic=20=

>> method exists.
>> Non-public methods can be called, but public methods cannot.
>> This is the opposite of the method visibility policy.
>>=20
>> =46rom a practical point of view:
>> If you can call Non-static public methods through the __callStatic=20
>> magic method, you can write code like Laravel ORM more simply and =
tidy.
>>=20
>> <code>
>> User::foo()->bar();
>> </code>
>>=20
>> =3D=3D=3D=3D Before =3D=3D=3D=3D
>>=20
>> <code>
>> class Foo
>> {
>>    protected static ?Foo $instance =3D null;
>>=20
>>    public static function __callStatic($method, $args)
>>    {
>>        $instance =3D self::$instance ?? self::$instance =3D new =
static();
>>        return $instance->__call($method, $args);
>>    }
>>=20
>>    public function __call($method, $args)
>>    {
>>        if (method_exists($this, $method)) {
>>            return $instance->$method(...$args);
>>        }
>>=20
>>        return $this;
>>    }
>>=20
>>    protected function bar()
>>    {
>>        echo __METHOD__ . '<br />';
>>=20
>>        return $this;
>>    }
>>=20
>>    protected function baz()
>>    {
>>        echo __METHOD__ . '<br />';
>>=20
>>        return $this;
>>    }
>> }
>>=20
>> Foo::bar()->baz();
>> (new Foo())->bar()->baz();
>> </code>
>>=20
>> There is no error, but the concept of method visibility is broken.
>> All Non-public methods can be called at instance scope.
>>=20
>> =3D=3D=3D=3D After =3D=3D=3D=3D
>>=20
>> <code>
>> class Foo
>> {
>>    protected static ?Foo $instance =3D null;
>>=20
>>    public static function __callStatic($method, $args)
>>    {
>>        $instance =3D self::$instance ?? self::$instance =3D new =
static();
>>=20
>>        if (method_exists($instance, $method)) {
>>            return $instance->$method(...$args);
>>        }
>>=20
>>        return $instance;
>>    }
>>=20
>>    public function bar()
>>    {
>>        echo __METHOD__ . '<br />';
>>=20
>>        return $this;
>>    }
>>=20
>>    public function baz()
>>    {
>>        echo __METHOD__ . '<br />';
>>=20
>>        return $this;
>>    }
>> }
>>=20
>> Foo::bar()->baz();
>> (new Foo())->bar()->baz();
>> </code>
>>=20
>> This is more tidy.
>> Only public methods are callable at instance scope.
>=20
> That calling bar() works at all in this example is rather accidental.  =
The whole point of a non-static method is that it has an implicit =
required $this argument to it.  Without a required argument, a method =
cannot be called, because it is supposed to fail.
>=20
> In fact, even your "before" example fails: https://3v4l.org/moH0s

It does work after having corrected the obvious bug in the `bar()` =
method.

>=20
> I don't think what you describe is even possible, nor would it be a =
good idea.

Why wouldn=E2=80=99t it possible? Couldn=E2=80=99t the engine invoke =
__callStatic() instead of complaining that the targeted method is not =
static? (I don=E2=80=99t have opinion on whether it is a good idea, =
though)

=E2=80=94Claude