Oh, I did this a long time ago (actually towards the end of last year).
Assumptions
- You are using Wordpress permalinks with mod_rewrite or a similar option.
- You don't have register_globals() turned on. Turn it off to ensure Wordpress's global variables don't get removed by Kohana.
Renaming
First, you need to rename the __() function in Kohana. Say, you rename it to __t(). You'd need to replace it everywhere it appears, which if you use an editor like Netbeans that can find usages of a function or method is pretty easy.
Hierarchy
The next decision you need to make is whether you want to load Wordpress inside Kohana or Kohana inside Wordpress. I prefer the latter, which I'm documenting below. I could document the latter if you'd prefer to go that route.
I put the kohana directory in my theme directory.
In your functions.php file of your theme, simply
include TEMPLATEPATH . '/kohana/index.php';
Kohana Configuration
Your Kohana's index.php file also needs some work. Remove the lines that look for install.php as they will load ABSPATH . WPINC . 'install.php' instead and display an error message in your wordpress admin. You also need to change the error_reporting as at the moment Wordpress fails E_STRICT.
You will very likely need to remove the last few lines of your bootstrap (in Kohana) that process the request, and change your init:
Kohana::init(array(
'base_url' => get_bloginfo('home') . '/',
'index_file' => '',
));
In either your Wordpress functions.php file or in your bootstrap, add these lines:
remove_filter('template_redirect', 'redirect_canonical');
add_filter('template_redirect', 'Application::redirect_canonical');
where Application is a class of your choosing.
My code for the Application class (without the class definition) is:
public static function redirect_canonical($requested_url=null, $do_redirect=true)
{
if (is_404() && self::test_url())
{
echo Request::instance()->execute()->send_headers()->response;
exit;
}
redirect_canonical($requested_url, $do_redirect);
}
public static function test_url($url = NULL)
{
if ($url === NULL)
{
$url = str_replace('?'.$_SERVER['QUERY_STRING'], '', $_SERVER['REQUEST_URI']);
$url = trim($url, '/');
}
foreach (Route::all() as $route)
{
/* @var $route Route */
if ($params = $route->matches($url))
{
$controller = 'controller_';
if (isset($params['directory']))
{
// Controllers are in a sub-directory
$controller .= strtolower(str_replace('/', '_', $params['directory'])).'_';
}
// Store the controller
$controller .= $params['controller'];
$action = Route::$default_action;
if (isset($params['action']))
{
$action = $params['action'];
}
if (!class_exists($controller))
return false;
if (!(method_exists($controller, 'action_' . $action) || method_exists($controller, '__call')))
return false;
return true;
}
}
return false;
}
which lets Wordpress do it's redirect for any page that may have moved e.g. /about/calendar to /calendar as long as you don't have an about controller and calendar action defined.
So there you have it. Any urls not defined within Wordpress will fall to your defined controller (or use your theme's 404 template).
Additional
This isn't required, but you could put your theme's header.php under your kohana views folder (application or in a module) and from any of your theme files
echo View::factory('header')
You could do the same thing with your footer (or any other files for that matter). In your header.php, you could also do this:
if (isset($title)) echo $title; else wp_title(YOUR_OPTIONS);
That way you could in your controller
echo View::factory('header')->set('title', 'YOUR_TITLE');
To keep urls consistent, you may have to take off the / from the end of Wordpress permalinks so /%year%/%monthnum%/%day%/%postname%/ becomes /%year%/%monthnum%/%day%/%postname%, etc
Please let me know if you need any more help integrating Wordpress and Kohana.