Declare class from Variable in PHP

Question

how can I declare new php class from string variable:

example:

$foo = 'Foo_Class';
if(!class_exists($foo)){
  class $foo extends Bar{}
}

May be duplicated. http://stackoverflow.com/questions/7131295/dynamic-class-names-in-php — RJParikh, Apr 15 '16 at 10:35
If the class_exists returns true, why would you then declare a new class of the same name, you would get an error. Surely you meant `new $foo()` — Antony D'Andrea, Apr 15 '16 at 10:37
@RuchishParikh my question is different from that, What i want is Declare not instantiate. — J.Aries, Apr 16 '16 at 13:55
@AntonyD'Andrea, that was my typo. sorry for confusion. I edited the code. — J.Aries, Apr 16 '16 at 13:58

Krac · Answer 1 · 2016-04-15T11:18:45.353

3

You can only do this by using eval:

$foo = 'Foo_Class';
if(! class_exists($foo)){
  eval("class $foo extends Bar{}");
}

But I wouldn't recommend this aproach.

edited Apr 15 '16 at 11:18

answered Apr 15 '16 at 10:37

Krac

I would like to try this, but what security holes Im dealing with? – J.Aries Apr 16 '16 at 13:56
So far this is the only i know. – J.Aries Apr 18 '16 at 04:20
@J.Aries Maybe not strictly PHP, but here you will get basic understanding why eval overall is a bad practice: https://blogs.msdn.microsoft.com/ericlippert/2003/11/01/eval-is-evil-part-one/ – Krac Apr 18 '16 at 13:23

1 Answers1