Added __callStatic(). Added warning to enforce public visibility and non-static declaration.
Added __isset() and __unset(). Added support for __get() for overloading of private properties.
Added __get().
__set() is run when writing data to inaccessible properties.
__get() is utilized for reading data from inaccessible properties.
__isset() is triggered by calling isset() or empty() on inaccessible properties.
__unset() is invoked when unset() is used on inaccessible properties.
The $name argument is the name of the property being interacted with. The __set() method's $value argument specifies the value the $name'ed property should be set to.
Property overloading only works in object context. These magic methods will not be triggered in static context. Therefore these methods should not be declared static. As of PHP 5.3.0, a warning is issued if one of the magic overloading methods is declared static.
Note:
The return value of __set() is ignored because of the way PHP processes the assignment operator. Similarly, __get() is never called when chaining assignments together like this:
$a = $obj->b = 8;
<?php
class PropertyTest
{
/** Location for overloaded data. */
private $data = array();
/** Overloading not used on declared properties. */
public $declared = 1;
/** Overloading only used on this when accessed outside the class. */
private $hidden = 2;
public function __set($name, $value)
{
echo "Setting '$name' to '$value'\n";
$this->data[$name] = $value;
}
public function __get($name)
{
echo "Getting '$name'\n";
if (array_key_exists($name, $this->data)) {
return $this->data[$name];
}
$trace = debug_backtrace();
trigger_error(
'Undefined property via __get(): ' . $name .
' in ' . $trace[0]['file'] .
' on line ' . $trace[0]['line'],
E_USER_NOTICE);
return null;
}
/** As of PHP 5.1.0 */
public function __isset($name)
{
echo "Is '$name' set?\n";
return isset($this->data[$name]);
}
/** As of PHP 5.1.0 */
public function __unset($name)
{
echo "Unsetting '$name'\n";
unset($this->data[$name]);
}
/** Not a magic method, just here for example. */
public function getHidden()
{
return $this->hidden;
}
}
echo "<pre>\n";
$obj = new PropertyTest;
$obj->a = 1;
echo $obj->a . "\n\n";
var_dump(isset($obj->a));
unset($obj->a);
var_dump(isset($obj->a));
echo "\n";
echo $obj->declared . "\n\n";
echo "Let's experiment with the private property named 'hidden':\n";
echo "Privates are visible inside the class, so __get() not used...\n";
echo $obj->getHidden() . "\n";
echo "Privates not visible outside of class, so __get() is used...\n";
echo $obj->hidden . "\n";
?>
The above example will output:
Setting 'a' to '1' Getting 'a' 1 Is 'a' set? bool(true) Unsetting 'a' Is 'a' set? bool(false) 1 Let's experiment with the private property named 'hidden': Privates are visible inside the class, so __get() not used... 2 Privates not visible outside of class, so __get() is used... Getting 'hidden' Notice: Undefined property via __get(): hidden in <file> on line 70 in <file> on line 29
__call() is triggered when invoking inaccessible methods in an object context.
__callStatic() is triggered when invoking inaccessible methods in a static context.
The $name argument is the name of the method being called. The $arguments argument is an enumerated array containing the parameters passed to the $name'ed method.
<?php
class MethodTest
{
public function __call($name, $arguments)
{
// Note: value of $name is case sensitive.
echo "Calling object method '$name' "
. implode(', ', $arguments). "\n";
}
/** As of PHP 5.3.0 */
public static function __callStatic($name, $arguments)
{
// Note: value of $name is case sensitive.
echo "Calling static method '$name' "
. implode(', ', $arguments). "\n";
}
}
$obj = new MethodTest;
$obj->runTest('in object context');
MethodTest::runTest('in static context'); // As of PHP 5.3.0
?>
The above example will output:
Calling object method 'runTest' in object context Calling static method 'runTest' in static context
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