On Mon, Jan 16, 2017 at 9:49 AM, Michał Brzuchalski <mic...@brzuchalski.com>
wrote:
> Hi Marco,
>
> 2017-01-16 0:27 GMT+01:00 Marco Pivetta <ocram...@gmail.com>:
>
>> Hi Wes,
>>
>> This has been discussed before, and it's currently used to intercept
>> access
>> to properties. Since we don't have property accessors (sigh), the code
>> (simplified version) would look like following:
>>
>> class Foo
>> {
>> public $bar = 'baz';
>> }
>>
>> class FooInterceptor extends Foo
>> {
>> private $wrapped;
>> public function __construct(Foo $wrapped)
>> {
>> $this->wrapped = $wrapped;
>> unset($this->bar);
>> }
>> public function __get(string $name)
>> {
>> var_dump('reading ' . $name);
>> return $this->wrapped->$name;
>> }
>> }
>>
>> $foo = new FooInterceptor(new Foo);
>>
>> var_dump($foo->bar);
>>
>> You can see a working example at https://3v4l.org/UtugD
>
>
> There is one more thing might be confusing - reflection tells there still
> exists bar property after unset while it's realy not.
> For example https://3v4l.org/NAg1l
>
> $class = new ReflectionClass(FooInterceptor::class);
> $property = $class->getProperty('bar');
> var_dump($property); // still exists while actually being unset may cause
> errors
>
> I'm sticking to extending class without magic _get method implemented.
>
>
>>
>>
>> This behavior is protected from regressions since PHP 5.4, but has been
>> working since 5.0:
>> https://github.com/php/php-src/blob/cd2b462a2742c79256668d47
>> 36644e34573c33d9/tests/classes/unset_properties.phpt
>>
>> We can most probably get rid of this weird behavior once property
>> accessors
>> are in the language.
>>
>> Greets,
>>
>> Marco Pivetta
>>
>> http://twitter.com/Ocramius
>>
>> http://ocramius.github.com/
>>
>> On Mon, Jan 16, 2017 at 12:20 AM, Wes <netmo....@gmail.com> wrote:
>>
>> > Hello elephpants.
>> >
>> > Currently PHP allows explicitly declared fields (eg public $foo = 10;)
>> to
>> > be removed entirely through unset (eg unset($obj->foo)).
>> >
>> > Now that isn't really an issue as properties in php are currently
>> untyped
>> > and therefore nullable; at worst you would get a notice. But it would
>> > become an issue with typed fields... that might get a second chance
>> sooner
>> > or later.
>> >
>> > But regardless of that, it looks very strange to me that this is allowed
>> > for fields that are explicitly declared. I think unset() should set the
>> > field to null if it's declared in the class, and remove the field
>> > altogether only if it was defined dynamically.
>> >
>> > On the other hand, this is just one of many ways of hacking php that
>> just
>> > exist and we accept / don't care because we have faith in other people
>> not
>> > doing nasty stuff with our code. This might sound ironic it is actually
>> not
>> > :P
>> >
>> > However, I am curious: what you think about this? Should PHP do
>> something
>> > in regard? Should this continue to work like it does now? Why do you
>> feel
>> > it should do the one or the other?
>> >
>>
>
Hi Michał,
Reflection will also trigger `__get` in this scenario, which is expected
and was also reverted multiple times in "fixes" that worked around or
forgot to call the property access guards.
class Foo
{
public $bar = 'baz';
}
class FooInterceptor extends Foo
{
private $wrapped;
public function __construct(Foo $wrapped)
{
$this->wrapped = $wrapped;
unset($this->bar);
}
public function __get(string $name)
{
var_dump('reading ' . $name);
return $this->wrapped->$name;
}
}
$foo = new FooInterceptor(new Foo);
$reflectionFooBar = new \ReflectionProperty(Foo::class, 'bar');
var_dump($reflectionFooBar->getValue($foo));
See https://3v4l.org/6JtWT for a working example.
You can see
https://github.com/Ocramius/ProxyManager/tree/cce5477857504997baf3168974b8f1283516a686/tests/language-feature-scripts
for
As I already mentioned, this hack is currently necessary to make property
access interception transparent, which is common for most AOP-oriented
code. We need an alternate approach to make this happen, before such a
feature can be dropped.
Marco Pivetta
http://twitter.com/Ocramius
http://ocramius.github.com/
