如何使用get_object_vars获取属性的层次结构顺序？

Question

I have some classes that extend each other, each time adding more properties.

Now I need to get a list of all properties of a class, but in the order that they were declared, with the properties of the parent class first.

For example :

class foo {
    public $a = 1;
    public $c = 2;
    public $d = 3;
}

class foo2 extends foo {
    public $b = 4;
}

$test = new foo2;

var_dump(get_object_vars($test));

This gives :

array(4) { ["b"]=> int(4) ["a"]=> int(1) ["c"]=> int(2) ["d"]=> int(3) } 

but I want :

array(4) { ["a"]=> int(1) ["c"]=> int(2) ["d"]=> int(3) ["b"]=> int(4) } 

Is there any way this could be achieved?

UPDATE: The reason I need this, is because I'm converting a file that uses the STEP (EXPRESS ISO 10303-21) format (and back!). (See this for more information : http://en.wikipedia.org/wiki/ISO_10303-21) This format is some kind of serialized objects structure. I recreated all object classes in PHP, but since in STEP the order of the properties is crucial, I need the exact same order of the properties.

Answer 1

Is there any way this could be achieved?

It's not totally clear what exactly you need (and what your motivation is which would have been good to know to give concrete suggestions), but what you're looking for is possible by using PHP Reflection.

You do so by getting all ancestor classes until the root class, and then you read all properties with it on all these classes. See the ReflectionClass class with it's ReflectionClass::getDefaultProperties() method.

See as well

• php: determining class hierarchy of an object at runtime

Hope this is helpful, let me know if you run into any problems with that.

Example:

<?php

class root {
   public $property = 1;
}

class parentClass extends root {
   public $ads = FALSE;
}

class child extends parentClass {
   public $child = TRUE;
}

$class = 'child';

$chain = array_reverse(class_parents($class), true) + [$class => $class];

$props = [];

foreach($chain as $class)
{
     $props += (new ReflectionClass($class))->getDefaultProperties();    
}

print_r($props);

Program Output:

Array
(
    [property] => 1
    [ads] => 
    [child] => 1
)