NAME

       Plack::Middleware::HTTPExceptions - Catch HTTP exceptions

SYNOPSIS

         use HTTP::Exception;

         my $app = sub {
             # ...
             HTTP::Exception::500->throw;
         };

         builder {
             enable "HTTPExceptions", rethrow => 1;
             $app;
         };

DESCRIPTION

       Plack::Middleware::HTTPExceptions is a PSGI middleware component to catch exceptions from
       applications that can be translated into HTTP status codes.

       Your application is supposed to throw an object that implements a "code" method which
       returns the HTTP status code, such as 501 or 404. This middleware catches them and creates
       a valid response out of the code. If the "code" method returns a code that is not an HTTP
       redirect or error code (3xx, 4xx, or 5xx), the exception will be rethrown.

       The exception object may also implement "as_string" or overload stringification to
       represent the text of the error. The text defaults to the status message of the error
       code, such as Service Unavailable for 503.

       Finally, the exception object may implement "as_psgi", and the result of this will be
       returned directly as the PSGI response.

       If the code is in the 3xx range and the exception implements the 'location' method
       (HTTP::Exception::3xx does), the Location header will be set in the response, so you can
       do redirects this way.

       There are CPAN modules HTTP::Exception and HTTP::Throwable, and they are perfect to throw
       from your application to let this middleware catch and display, but you can also implement
       your own exception class to throw.

       If the thrown exception is not an object that implements either a "code" or an "as_psgi"
       method, a 500 error will be returned, and the exception is printed to the psgi.errors
       stream.  Alternatively, you can pass a true value for the "rethrow" parameter for this
       middleware, and the exception will instead be rethrown. This is enabled by default when
       "PLACK_ENV" is set to "development", so that the StackTrace middleware can catch it
       instead.

AUTHOR

       Tatsuhiko Miyagawa

SEE ALSO

       paste.httpexceptions HTTP::Exception HTTP::Throwable