Custom Error Pages
Custom error pages allow you to display a friendly error message to users, rather than the standard Kohana stack trace.
Prerequisites
- You will need
'errors' => TRUEpassed to [Kohana::init]. This will convert PHP-errors into exceptions which are easier to handle (The default value isTRUE). - Custom error pages will only be used to handle throw [HTTP_Exception]’s. If you simply set a status of, for example, 404 via [Respose::status] the custom page will not be used.
Extending the HTTP_Exception classes
Handling [HTTP_Exception]’s in Kohana has become easier with the changes introduced in 3.3.
For each [HTTP_Exception] class we can individually override the generation of the [Response] instance.
[!!] Note: We can also use HMVC to issue a sub-request to another page rather than generating the [Response] in the [HTTP_Exception] itself.
For example, to handle 404 pages we can do this in APPPATH/classes/HTTP/Exception/404.php:
class HTTP_Exception_404 extends Kohana_HTTP_Exception_404 {
/**
* Generate a Response for the 404 Exception.
*
* The user should be shown a nice 404 page.
*
* @return Response
*/
public function get_response()
{
$view = View::factory('errors/404');
// Remembering that `$this` is an instance of HTTP_Exception_404
$view->message = $this->getMessage();
$response = Response::factory()
->status(404)
->body($view->render());
return $response;
}
}
Another example, this time to handle 401 Unauthorized errors (aka “Not Logged In”) we can do this in APPPATH/classes/HTTP/Exception/401.php:
class HTTP_Exception_401 extends Kohana_HTTP_Exception_401 {
/**
* Generate a Response for the 401 Exception.
*
* The user should be redirect to a login page.
*
* @return Response
*/
public function get_response()
{
$response = Response::factory()
->status(401)
->headers('Location', URL::site('account/login'));
return $response;
}
}
Finally, to override the default [Response] for all [HTTP_Exception]’s without a more specific override we can do this in APPPATH/classes/HTTP/Exception.php:
class HTTP_Exception extends Kohana_HTTP_Exception {
/**
* Generate a Response for all Exceptions without a more specific override
*
* The user should see a nice error page, however, if we are in development
* mode we should show the normal Kohana error page.
*
* @return Response
*/
public function get_response()
{
// Lets log the Exception, Just in case it's important!
Kohana_Exception::log($this);
if (Kohana::$environment >= Kohana::DEVELOPMENT)
{
// Show the normal Kohana error page.
return parent::get_response();
}
else
{
// Generate a nicer looking "Oops" page.
$view = View::factory('errors/default');
$response = Response::factory()
->status($this->getCode())
->body($view->render());
return $response;
}
}
}
