php教程

ReflectionClass::getDefaultProperties

(PHP 5, PHP 7)

ReflectionClass::getDefaultProperties获取默认属性

说明

public ReflectionClass::getDefaultProperties ( void ) : array

获取类的默认属性(包括了继承的属性)。

Note:

This method only works for static properties when used on internal classes. The default value of a static class property can not be tracked when using this method on user defined classes.

参数

此函数没有参数。

返回值

默认属性的数组,其键是属性的名称,其值是属性的默认值或者在属性没有默认值时是 NULL。 这个函数不区分静态和非静态属性,也不考虑可见性修饰符。

范例

Example #1 ReflectionClass::getDefaultProperties() 例子

<?php
class Bar {
    protected 
$inheritedProperty 'inheritedDefault';
}

class 
Foo extends Bar {
    public 
$property 'propertyDefault';
    private 
$privateProperty 'privatePropertyDefault';
    public static 
$staticProperty 'staticProperty';
    public 
$defaultlessProperty;
}

$reflectionClass = new ReflectionClass('Foo');
var_dump($reflectionClass->getDefaultProperties());
?>

以上例程会输出:

array(5) {
   ["staticProperty"]=>
   string(14) "staticProperty"
   ["property"]=>
   string(15) "propertyDefault"
   ["privateProperty"]=>
   string(22) "privatePropertyDefault"
   ["defaultlessProperty"]=>
   NULL
   ["inheritedProperty"]=>
   string(16) "inheritedDefault"
}

参见

User Contributed Notes

articice at ua dot fm 17-Mar-2016 12:15
runaurufu is not quite right, get_class_vars() does not return protected params, while this one does.

Thus it's extremely useful when having an abstract parent class and protected properties overriding in children.
For example, I use a class factory and one of the children has some static test methods that still need to output a paramether name, like $this->name, etc. With this example code, one can use static::getNotStaticProperty('name'), but not get_class_vars('name').

Try it:

trait static_reflector {
    /*
     * a purely static function that returns default properties of the non-static instance of the same class
     */
    static protected function getNonStaticProperty($key) {
        $me = get_class();
        $reflectionClass = new \ReflectionClass($me);
        $properties_list = $reflectionClass->getDefaultProperties();
        if (isset($properties_list[$key]))
            return $var_name = $properties_list[$key];
        else throw new RuntimeException("BUG: Unable to reflect non-static property '{$key}' from default properties of class {$me}");
    }
}

class a {

    use \static_reflector;

    protected $key_a = 'test ok';

    public static function test() {
        echo static::getNonStaticProperty('key_a')."\n";

        try {
            print static::getNonStaticProperty('key_b');
            echo "FAIL No exception thrown";
        } catch (RuntimeException $e) {
            echo "OK ".$e->getMessage();
        }

    }
}

echo get_class_vars('a')['key_a'];
a::test();

this will return:
Notice: Undefined index: key_a in ...
test ok
OK BUG: Unable to reflect non-static property 'key_b' from default properties of class a

ps: Yes, this is copied from a unit test.
runaurufu AT gmail.com 04-Aug-2011 01:02
Worth noting that it will not return private parameters of parent class...
so it works exactly as get_class_vars or get_object_vars
captainjester at hotmail dot com 20-Jan-2010 03:20
This will return all properties in a class and any parent classes.  The array will have keys set to the property names and empty values.

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