get_object_vars（）可以从magic __get（）返回字段吗？

Question

I'm running through a set of arrays and objects for further processing. If it's an object i use get_object_vars($obj) to get its proberties. But if that object uses magic getters/setters, it returns an empty array. Here a little demo of the issue:

class Foo {
    protected
        $fields = array(
            'foo'=>1,
            'bar'=>2
        );
    function __get($key) {
        return $this->fields[$key];
    }
    function __isset($key) {
        return array_key_exists($key,$this->fields);
    }
}

$foo = new Foo();
var_dump(get_object_vars($foo));

I want that get_object_vars returns the $fields key-value pairs. Is there any way to go, or any method to implement in Foo to make it work?

thanks for any hint.

Answer 1

That is not related to magic methods, but with the fact that get_object_vars() returns an array of accessible non-static properties for the specified object relative to scope. It will return all properties if the call is from inside the objects, but, only public from outside the object. You can however, use the IteratorAggregate interface, and ArrayIterator class, and combine that with iterator_to_array() function to obtain similar behavior and some additional benefits, as in this example.

class Foo implements IteratorAggregate {
    protected
        $fields = array(
            'foo' => 1,
            'bar' => 2
        );

    function __get( $name ) {
        return array_key_exists( $name, $this->fields ) ? $this->fields[$name] : null;
    }

    public function __set( $name, $value )
    {
        $this->fields[$name] = $value;
    }

    function __isset( $name ) {
        return isset( $this->fields[$name] );
    }

    public function getIterator() {
        return new ArrayIterator( $this->fields );
    }
}

$foo = new Foo();
$foo->baz = 3;

foreach( $foo as $key => $value ) {
    echo "$key: $value ";   // OUTPUT: foo: 1 bar: 2 baz: 3
}

array_walk( ( iterator_to_array( $foo ) ), function( $value, $key ) {
    echo "$key: $value ";   // OUTPUT: foo: 1 bar: 2 baz: 3
});

print_r( iterator_to_array( $foo ) );   // OUTPUT: Array ( [foo] => 1 [bar] => 2 [baz] => 3 )