PHP Reflection Feature detection of classes or objects
Example
Feature detection of classes can partly be done with the property_exists and method_exists functions.
class MyClass {
public $public_field;
protected $protected_field;
private $private_field;
static $static_field;
const CONSTANT = 0;
public function public_function() {}
protected function protected_function() {}
private function private_function() {}
static function static_function() {}
}
// check properties
$check = property_exists('MyClass', 'public_field'); // true
$check = property_exists('MyClass', 'protected_field'); // true
$check = property_exists('MyClass', 'private_field'); // true, as of PHP 5.3.0
$check = property_exists('MyClass', 'static_field'); // true
$check = property_exists('MyClass', 'other_field'); // false
// check methods
$check = method_exists('MyClass', 'public_function'); // true
$check = method_exists('MyClass', 'protected_function'); // true
$check = method_exists('MyClass', 'private_function'); // true
$check = method_exists('MyClass', 'static_function'); // true
// however...
$check = property_exists('MyClass', 'CONSTANT'); // false
$check = property_exists($object, 'CONSTANT'); // false
With a ReflectionClass, also constants can be detected:
$r = new ReflectionClass('MyClass');
$check = $r->hasProperty('public_field'); // true
$check = $r->hasMethod('public_function'); // true
$check = $r->hasConstant('CONSTANT'); // true
// also works for protected, private and/or static members.
Note: for property_exists and method_exists, also an object of the class of interest can be provided instead of the class name. Using reflection, the ReflectionObject class should be used instead of ReflectionClass.
