Twig can't find extension... what namespace should I use? - twig

Question

I am passing a BASE64 encoded string to a twig template that I would like to have a twig extension de-code.
I installed twig with composer and I'm not using any other frameworks and most of the extension examples I've found seem to assume you are, and I think that that is causing me trouble. I can't seem to get twig to find my extension.
So I think I'm having a name space issue. my setup:
root/
-index.php
-vendor/
-twig/
Given this setup, where should I put the extension file and what name space should be at the top of the file? What is the proper way to load it?
Many thanks in advance!

Answer 1

If your app isn't too complex, you can simply add extension in place where you register and load Twig itself.
// index.php
require_once __DIR__ . '/vendor/autoload.php';
$loader = new Twig_Loader_Filesystem('/path/to/templates');
$twig = new Twig_Environment($loader, array(
'cache' => '/path/to/compilation_cache',
));
// an anonymous function:
$base64Decode = new Twig_Filter('base64_decode', function ($string) {
return base64_decode($string);
});
// or a simple PHP function:
$base64Decode = new Twig_Filter('base64_decode', 'base64_decode');
// add the function to your Twig environment:
$twig->addFilter($base64Decode);