Not able to access private protect member in iterator php - php

Question

Here is the data Iterator implementation
//Data Iterator
class DataIterator implements Iterator
{
public $data ;
public function __construct(Data $obj)
{
$this->data = $obj;
}
public function rewind()
{
$this->properties = get_object_vars($this->data);
}
public function valid()
{
if (key($this->properties) === null )
{
return false;
}
return true;
}
public function key()
{
return key($this->properties);
}
public function current()
{
return current($this->properties);
}
public function next()
{
next($this->properties);
}
}
and here is data class
/*Data Class*/
class Data implements IteratorAggregate
{
public $name;
private $age;
protected $address;
public $country;
public $state;
public function __construct($name, $age, $address, $country = 'USA', $state = 'NH')
{
$this->name = $name;
$this->age = $age;
$this->address = $address;
$this->country = $country;
$this->state = $state;
}
function getIterator()
{
return new DataIterator($this);
}
}
And here is the calling part
$data = new Data('Joker', '27', 'California');
foreach($data->getIterator() as $key => $value)
{
echo $key , ' ', $value, '<br>';
}
output
name Joker
country USA
state NH
Notice that the output does not contain my private and protected properties (age, address) output.
How do I tell Iterator to output those as well?

Answer 1

You cannot tell the iterator to output those properties because they are simply not accessible from the outside (i.e. the point where the iterator does get_object_vars($this->data).
There are two ways you could go about doing this:
By having the data object pass the values to the iterator.
Use the reflection API to pull them out by force (verbose, slow!).
But before going ahead with #1 as the preferred option, stop for a moment and ask yourself: why does the iterator expose non-public members of the data object?
Making something private means "You people don't really need to know about this; it may go away in the future, or it may change beyond recognition". If it's something that the outside world cares about, then why is it not public (either directly, or exposed through a public getter)? A rethink of what this iterator's purpose is might be in order.
That said, here's how you would do #1:
class DataIterator implements Iterator
{
public $data;
private $properties;
public function __construct(Data $obj, array $propeties)
{
$this->data = $obj;
$this->properties = $properties;
}
public function rewind()
{
// Arguably horrible trick to refresh the property map without
// demanding that Data exposes a separate API just for this purpose
$newIterator = $this->data->getIterator();
$this->properties = $newIterator->properties;
}
}
class Data implements IteratorAggregate
{
function getIterator()
{
return new DataIterator($this, get_object_vars($this));
}
}

Answer 2

Public, private and protected are access modifiers. They are designed to restrict the accessibility of your class attributes.
Public means that any one can access that attribute, so if someone wants, they can change the value, without that you know it.
Private mean that the attribute is only accessible INSIDE the class,
so nobody can "mess" with those properties from OUTSIDE the class.
Protected is similar like Private, but child classes (classes that
inherit from that class) have access to it.
You are making age and address private, so you are basically saying, nobody is allowed to access these attributes. If you want to access private/protected attributes, you will have to make getters and setters and call these functions, or make the attributes public.

Answer 3

try get_class_vars
$this->properties = get_class_vars(get_class($this->data));
instead of
$this->properties = get_object_vars($this->data);