ArrayObject iteration

Question

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.

Answer 1

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

Answer 2

In my opinion your code works as expected, if you want to make sure that your values handled properly use correct methods:

$a = new obsecureArray();
$a->offsetSet('test', 'Value');
$a->offsetSet(2, '1');

also instead of

define('BR','
');

there is predefined php property PHP_EOL

Answer 3

You'll want to implement Iterator or IteratorAggregate. You have more control over the former, but the latter is simpler to implement (probably with more overhead):

class People implements IteratorAggregate {
    protected $children;

    // ...

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

See the Iterator for boilerplate methods for that interface.

Answer 4

You'll need to set a custom iterator class:

<?php

class SecureArray extends ArrayObject {

    public function __construct($array = array()) {
        parent::__construct($array);
        $this->setIteratorClass('SecureIterator');
    }

    public function offsetSet($name, $value) {
        parent::offsetSet( base64_encode($name), base64_encode($value) );
    }

    public function offsetGet($name) {
        return base64_decode( parent::offsetGet( base64_encode($name) ) );
    }

    public function offsetExists($name) {
        return parent::offsetExists( base64_encode($name) );
    }

    public function offsetUnset($name) {
        return parent::offsetUnset( base64_encode($name) );
    }
}

class SecureIterator extends ArrayIterator {

    function current() {
        return base64_decode(parent::current());
    }

    function key() {
        return base64_decode(parent::key());
    }
}