如何在Symfony2中使用misc函数？

Where do I store misc functions? How do I use them? Should it be a DependencyInjection? Should it just be a class and do I do something like use Acme\Bundle\AcmeBundle\Misc\ClientIPChecker?

Say I have a function:

<?php
class ClientIPChecker {
    public static function isLocal(Request $request){
        return in_array('127.0.0.1', $request->getClientIp())
    }
}

And I want to use this function in two controllers. How do I do this in Symfony2?

If you have a set of consistent function put them in a class/service. If functions do different things put them in the appropriate class/service. In this particular case, I'll go for either custom Request or custom Controller (probably the latter, avoding messing app.php or app_dev.php).

With custom controller this doesn't work:

// Automatic binding of $request parameter
public function indexAction(Request $request)
{
   // Won't work with custom controller
   if ($request->isLocal)) {
       // ...
   }

   // You have to do
   if ($this->getRequest()->isLocal()) {
       // stuff
   }
}

Option 1: extend Symfony Request

namespace My\HttpFoundation;

use Symfony\Component\HttpFoundation\Request as BaseRequest;

class Request extends BaseRequest
{
    public function isLocal()
    {
       return in_array('127.0.0.1', $this->getClientIp());
    }
}

Then in web/app.php and web/app_dev.php modify:

use Symfony\Component\HttpFoundation\Request;

to be:

use My\HttpFoundation\Request;

Option 2: create a BaseAbstractController and use it instead of Symfony controller

use Symfony\Bundle\FrameworkBundle\Controller\Controller;

abstract class BaseAbstractController extends Controller
{
    public function isRequestLocal()
    {
        return in_array('127.0.0.1', $this->getRequest()->getClientIp())
    }
}

Option 3: custom service as explained here