PHP getters and setters with array - php

Question

If i use magic __set to set a value to private var how could i set a var as an array ?
Im thinking of something like this, pretend i have a class with __get __set
$myclass->names = 'Name'; // Works
$myclass->names = array('n1'=>'Name1', 'n2' => 'Name2'); // works as well
//this does not work
$myclass->names['n1'] = 'Name1';
$myclass->names['n2'] = 'Name2';
Its the 2 last examples i want to get to work. Have tested various ways but cant figure it out.

Answer 1

You obviously don't output notices, otherwise you'd have gotten the error
Notice: Indirect modification of overloaded property Foo::$bar has no
effect
What you're trying to do is simply not possible. There is exactly one way to make arrays received through __get writable, but that is most likely not what you want.
<?php
class Foo {
protected $bar = array();
public function &__get($name) {
return $this->$name;
}
public function __set($name, $value) {
return $this->$name = $value;
}
}
$foo = new Foo();
$foo->bar = array('a', 'b', 'c');
echo $foo->bar[0]; // output "a"
$foo->bar[0] = 'z'; // fires warning
echo $foo->bar[0]; // output "z"
// all fine, but here's the catch:
$t =& $foo->bar;
$t = array('y');
echo $foo->bar[0]; // output "y"
Now that you've seen how returning values by reference can be a problem, you may be interested in ArrayObject. Something like
<?php
class Foo {
protected $bar = array();
public function __get($name) {
return new ArrayObject(&$this->$name);
}
public function __set($name, $value) {
return $this->$name = $value;
}
}
$foo = new Foo();
$foo->bar = array('a', 'b', 'c');
echo $foo->bar[0]; // output "a"
$foo->bar[0] = 'z'; // fires warning
echo $foo->bar[0]; // output "z"
// all fine, and no catch
$t =& $foo->bar;
$t = array('y');
echo $foo->bar[0]; // still outputs "z"

Answer 2

It won't work. $class->arr['key'] will execute the getter. So basically, what your code will look like is:
array('key' => 'value')['key'] = 'new value';
Which, obviously, does nothing. If you want that to work, you will have to declare the names as a public property.

Answer 3

This expression will invoke the getter:
$myclass->names['n1'] = 'Name1';
^^^^^^^^^^^^^^^
needs to be get
^^^^^^^^^^^^^^^^
assignment later
The only way to make that work is a fugly workaround. By letting the getter return an reference to the know array the following assignment could work.
function & __get($name) {
if (is_array($this->$name)) {
return & $this->$name;
}
else ...
}
So it's really only advisable if it significantly simplifies your API.

Answer 4

Try this code:
class Foo
{
private $bar;
public function __construct()
{
$this->bar = new ArrayObject(array());
}
public function __get($item)
{
if(property_exists($this, $item)) {
return $this->$item;
}
}
public function __set($item, $value)
{
if(property_exists($this, $item)) {
$this->{$item} = $value;
}
}
}
$obj = new Foo();
$obj->bar['color'] = 'green';
foreach($obj->bar as $attribute => $value) {
echo '<p>' . $attribute . ' : ' . $value . '</p>' . PHP_EOL;
}
// output => color : green