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phpsplarrayobject

ArrayObject iteration


Problem:

ArrayObject works as expected when the values are set or read manually, but when using a function (foreach for example) to iterate over it, things gets wicked.

It doesn't call the offset* methods that I have defined but instead uses the ArrayIterator methods.

Code:

The Class:

class obsecureArray extends ArrayObject {


    public function offsetSet($name, $value) {
        call_user_func_array(array('parent', __FUNCTION__), array(base64_encode($name), base64_encode($value)) );
    }

    public function offsetGet($name) {
        return base64_decode( call_user_func_array(array('parent', __FUNCTION__), (array) base64_encode($name) ) );
    }

    public function offsetExists($name) {
        return call_user_func_array(array('parent', __FUNCTION__), (array) base64_encode($name) );
    }

    public function offsetUnset($name) {
        return call_user_func_array(array('parent', __FUNCTION__), (array) base64_encode($name) );
    }
}

Usage Example:

$a = new obsecureArray();
$a['test'] = 'Value';
$a[2] = '1';

define('BR','<br />');
echo 'test: ',$a['test'],BR,'2: ',$a[2],BR;

foreach($a as $key => $value)
    echo 'Key: ',$key,' Value:',$value,BR;

Output:

test: Value
2: 1
Key: dGVzdA== Value:VmFsdWU=
Key: Mg== Value:MQ==

CodePad example.


Solution

  • I look into the ArrayObject __construct method documentation and found the third argument related to my problem:

    iterator_class:

    Specify the class that will be used for iteration of the ArrayObject object. ArrayIterator is the default class used.

    Now I could extended an ArrayIterator with my own offset* methods and pass it to my the constructor of ArrayObject, So I looked into ArrayIterator and it was almost identical to the ArrayObject except that it wasn't using an external iterator obviously. So All I had to do was extend ArrayIterator instead. and had to override the current and key method as well.

    So that I have:

    class obsecureArray extends ArrayIterator {
    
        public function offsetSet($name, $value) {
            call_user_func_array(array('parent', __FUNCTION__), array(base64_encode($name), base64_encode($value)));
        }
    
        public function offsetGet($name) {
            return base64_decode(call_user_func_array(array('parent', __FUNCTION__), (array) base64_encode($name)));
        }
    
        public function offsetExists($name) {
            return call_user_func_array(array('parent', __FUNCTION__), (array) base64_encode($name));
        }
    
        public function offsetUnset($name) {
            return call_user_func_array(array('parent', __FUNCTION__), (array) base64_encode($name));
        }
    
        public function key() {
            return base64_decode(parent::key());
        }
    
        public function current() {
            return base64_decode(parent::current());
        }
    
    
    
    }
    

    and it works perfectly as expected.

    and for:

    $a = new obsecureArray();
    $a['test'] = 'Value';
    $a[2] = '1';
    
    define('BR','<br />');
    echo 'test: ',$a['test'],BR,'2: ',$a[2],BR;
    
    foreach($a as $key => $value)
        echo 'Key: ',$key,' Value:',$value,BR;
    

    I got:

    test: Value
    2: 1
    Key: test Value:Value
    Key: 2 Value:1
    

    CodePad example