Class Object

Object is the ultimate ancestor of all instantiable classes.

It defines some handful methods and enhances object core of PHP: - access to undeclared members throws exceptions - support for conventional properties with getters and setters - support for event raising functionality - ability to add new methods to class (extension methods)

Properties is a syntactic sugar which allows access public getter and setter methods as normal object variables. A property is defined by a getter method or setter method (no setter method means read-only property).

$val = $obj->label;     // equivalent to $val = $obj->getLabel();
$obj->label = 'Nette';  // equivalent to $obj->setLabel('Nette');

Property names are case-sensitive, and they are written in the camelCaps or PascalCaps.

Event functionality is provided by declaration of property named 'on{Something}' Multiple handlers are allowed.

public $onClick;                // declaration in class
$this->onClick[] = 'callback';  // attaching event handler
if (!empty($this->onClick)) ... // are there any handlers?
$this->onClick($sender, $arg);  // raises the event with arguments

Adding method to class (i.e. to all instances) works similar to JavaScript prototype property. The syntax for adding a new method is:

MyClass::extensionMethod('newMethod', function(MyClass $obj, $arg, ...) { ... });
$obj = new MyClass;
$obj->newMethod($x);