Question

When I run the following code I get B as expected:

class A {
    public function __construct($file){}
}

class B extends A {
    public function __construct() {
        parent::__construct('test.flv');
    }
}

$b = new B();
print get_class($b);

However, consider a slightly modified version of this code (here ffmpeg_movie class is a part of http://ffmpeg-php.sourceforge.net library):

class B extends ffmpeg_movie {
    public function __construct() {
        parent::__construct('test.flv');
    }
}

$b = new B();
print get_class($b);

It returns ffmpeg_movie instead of B. Furthermore, it turns out that methods defined in B class aren’t accessible when using $b object:

class B extends ffmpeg_movie {
    public function __construct() {
        parent::__construct('test.flv');
    }

    public function test() {
        print 'ok';
    }
}

$b = new B();
$b->test();

Fatal error: Call to undefined method ffmpeg_movie::test() in .../test.php on line 13

What exactly is going on here and is there a workaround?

Answer 1

I didn’t find out what was the origin of the problem. I managed to solve it though by not extending ffmpeg_movie class directly and instead using __call, __get and __set PHP magic methods to mimic inheritance.