CakePHP - How to do reverse routing with slug?

Question

I am using CakePHP 1.3. I have a Product model. on the DB table among others there are id and slug fields.

If I have a product that is

Answer 1

I am not sure how bad this is but with the following code in the ProductsController:

function view($id)
{
    if( isset($_SERVER) && stristr($_SERVER["REQUEST_URI"],'view/') )
    {
        $this->Product->id = $id;
        $slug = $this->Product->field('slug');
        $this->redirect($id.'/'.$slug);
    }
    $data = $this->Product->find('first', array('conditions' => array('Product.id' => $id)));
    $this->set("data", $data);
}

If the page is accesses via /view/id it automatically redirects them to the current page using /id/slug

Now I can just use the default link scheme:

echo $html->link(
    'Product 37', 
    array('controller'=>'products', 'action' => 'view', 37)
);

and they will be redirected to the right URL.

Only problem is I am not sure how bad it is to have a redirect happening every time a user visits a product page?