Provided by: libhttp-exception-perl_0.04004-2_all 
NAME
HTTP::Exception - throw HTTP-Errors as (Exception::Class-) Exceptions
VERSION
version 0.04004
SYNOPSIS
HTTP::Exception lets you throw HTTP-Errors as Exceptions.
use HTTP::Exception;
# throw a 404 Exception
HTTP::Exception->throw(404);
# later in your framework
eval { ... };
if (my $e = HTTP::Exception->caught) {
# do some errorhandling stuff
print $e->code; # 404
print $e->status_message; # Not Found
}
You can also throw HTTP::Exception-subclasses like this.
# same 404 Exception
eval { HTTP::Exception::404->throw(); };
eval { HTTP::Exception::NOT_FOUND->throw(); };
And catch them accordingly.
# same 404 Exception
eval { HTTP::Exception::404->throw(); };
if (my $e = HTTP::Exception::405->caught) { do stuff } # won't catch
if (my $e = HTTP::Exception::404->caught) { do stuff } # will catch
if (my $e = HTTP::Exception::NOT_FOUND->caught) { do stuff } # will catch
if (my $e = HTTP::Exception::4XX->caught) { do stuff } # will catch all 4XX Exceptions
if (my $e = HTTP::Exception->caught) { do stuff } # will catch every HTTP::Exception
if (my $e = Exception::Class->caught) { do stuff } # catch'em all
You can create Exceptions and not throw them, because maybe you want to set some fields
manually. See "FIELDS" in HTTP::Exception and "ACCESSORS" in HTTP::Exception for more
info.
# is not thrown, ie doesn't die, only created
my $e = HTTP::Exception->new(404);
# usual stuff works
$e->code; # 404
$e->status_message # Not Found
# set status_message to something else
$e->status_message('Nothing Here')
# fails, because code is only an accessor, see section ACCESSORS below
# $e->code(403);
# and finally throw our prepared exception
$e->throw;
DESCRIPTION
Every HTTP::Exception is a Exception::Class - Class. So the same mechanisms apply as with
Exception::Class-classes. In fact have a look at Exception::Class' docs for more general
information on exceptions and Exception::Class::Base for information on what methods a
caught exception also has.
HTTP::Exception is only a factory for HTTP::Exception::XXX (where X is a number)
subclasses. That means that HTTP::Exception->new(404) returns a HTTP::Exception::404
object, which in turn is a HTTP::Exception::Base - Object.
Don't bother checking a caught HTTP::Exception::...-class with "isa" as it might not
contain what you would expect. Use the code- or status_message-attributes and the is_
-methods instead.
The subclasses are created at compile-time, ie the first time you make "use
HTTP::Exception". See paragraph below for the naming scheme of those subclasses.
Subclassing the subclasses works as expected.
NAMING SCHEME
HTTP::Exception::XXX
X is a Number and XXX is a valid HTTP-Statuscode. All HTTP-Statuscodes are supported. See
chapter "COMPLETENESS" in HTTP::Exception
HTTP::Exception::STATUS_MESSAGE
STATUS_MESSAGE is the same name as a HTTP::Status Constant WITHOUT the HTTP_ at the
beginning. So see "CONSTANTS" in HTTP::Status for more details.
IMPORTING SPECIFIC ERROR RANGES
It is possible to load only specific ranges of errors. For example
use HTTP::Exception qw(5XX);
HTTP::Exception::500->throw; # works
HTTP::Exception::400->throw; # won't work anymore
will only create HTTP::Exception::500 till HTTP::Exception::510. In theory this should
save some memory, but I don't have any numbers, that back up this claim.
You can load multiple ranges
use HTTP::Exception qw(3XX 4XX 5XX);
And there are aliases for ranges
use HTTP::Exception qw(CLIENT_ERROR)
The following aliases exist and load the specified ranges:
REDIRECTION => 3XX
CLIENT_ERROR => 4XX
SERVER_ERROR => 5XX
ERROR => 4XX 5XX
ALL => 1XX 2XX 3XX 4XX 5XX
And of course, you can load multiple aliased ranges
use HTTP::Exception qw(REDIRECTION ERROR)
ALL is the same as not specifying any specific range.
# the same
use HTTP::Exception qw(ALL);
use HTTP::Exception;
ACCESSORS (READONLY)
code
A valid HTTP-Statuscode. See HTTP::Status for information on what codes exist.
is_info
Return TRUE if "$self-"code> is an Informational status code (1xx). This class of status
code indicates a provisional response which can't have any content.
is_success
Return TRUE if "$self-"code> is a Successful status code (2xx).
is_redirect
Return TRUE if "$self-"code> is a Redirection status code (3xx). This class if status code
indicates that further action needs to be taken by the user agent in order to fulfill the
request.
is_error
Return TRUE if "$self-"code> is an Error status code (4xx or 5xx). The function return
TRUE for both client error or a server error status codes.
is_client_error
Return TRUE if "$self-"code> is an Client Error status code (4xx). This class of status
code is intended for cases in which the client seems to have erred.
is_server_error
Return TRUE if "$self-"code> is an Server Error status code (5xx). This class of status
codes is intended for cases in which the server is aware that it has erred or is incapable
of performing the request.
POD for is_ methods is Copy/Pasted from HTTP::Status, so check back there and alert me of
changes.
FIELDS
Fields are the same as ACCESSORS except they can be set. Either you set them during
Exception creation (->new) or Exception throwing (->throw).
HTTP::Exception->new(200, status_message => "Everything's fine");
HTTP::Exception::200->new(status_message => "Everything's fine");
HTTP::Exception::OK->new(status_message => "Everything's fine");
HTTP::Exception->throw(200, status_message => "Everything's fine");
HTTP::Exception::200->throw(status_message => "Everything's fine");
HTTP::Exception::OK->throw(status_message => "Everything's fine");
Catch them in your Webframework like this
eval { ... }
if (my $e = HTTP::Exception->caught) {
print $e->code; # 200
print $e->status_message # "Everything's fine" instead of the usual ok
}
status_message
DEFAULT The HTTP-Statusmessage as provided by HTTP::Status
A Message, that represents the Execptions' Status for Humans.
PLACK
HTTP::Exception can be used with Plack::Middleware::HTTPExceptions. But HTTP::Exception
does not depend on Plack, you can use it anywhere else. It just plays nicely with Plack.
COMPLETENESS
For the sake of completeness, HTTP::Exception provides exceptions for non-error-http-
statuscodes. This means you can do
HTTP::Exception->throw(200);
which throws an Exception of type OK. Maybe useless, but complete. A more realworld-
example would be a redirection
# all are exactly the same
HTTP::Exception->throw(301, location => 'google.com');
HTTP::Exception::301->throw(location => 'google.com');
HTTP::Exception::MOVED_PERMANENTLY->throw(location => 'google.com');
CAVEATS
The HTTP::Exception-Subclass-Creation relies on HTTP::Status. It's possible that the
Subclasses change, when HTTP::Status' constants are changed.
New Subclasses are created automatically, when constants are added to HTTP::Status. That
means in turn, that Subclasses disappear, when constants are removed from HTTP::Status.
Some constants were added to HTTP::Status' in February 2012. As a result HTTP::Exception
broke. But that was the result of uncareful coding on my side. I think, that breaking
changes are now quite unlikely.
AUTHOR
Thomas Mueller, "<tmueller at cpan.org>"
SEE ALSO
Exception::Class, Exception::Class::Base
Consult Exception::Class' documentation for the Exception-Mechanism and
Exception::Class::Base' docs for a list of methods our caught Exception is also capable
of.
HTTP::Status
Constants, Statuscodes and Statusmessages
Plack, especially Plack::Middleware::HTTPExceptions
Have a look at Plack, because it rules in general. In the first place, this Module was
written as the companion for Plack::Middleware::HTTPExceptions, but since it doesn't
depend on Plack, you can use it anywhere else, too.
BUGS
Please report any bugs or feature requests to "bug-http-exception at rt.cpan.org", or
through the web interface at http://rt.cpan.org/NoAuth/ReportBug.html?Queue=HTTP-Exception
<http://rt.cpan.org/NoAuth/ReportBug.html?Queue=HTTP-Exception>. I will be notified, and
then you'll automatically be notified of progress on your bug as I make changes.
SUPPORT
You can find documentation for this module with the perldoc command.
perldoc HTTP::Exception
You can also look for information at:
• RT: CPAN's request tracker
http://rt.cpan.org/NoAuth/Bugs.html?Dist=HTTP-Exception
<http://rt.cpan.org/NoAuth/Bugs.html?Dist=HTTP-Exception>
• AnnoCPAN: Annotated CPAN documentation
http://annocpan.org/dist/HTTP-Exception <http://annocpan.org/dist/HTTP-Exception>
• CPAN Ratings
http://cpanratings.perl.org/d/HTTP-Exception <http://cpanratings.perl.org/d/HTTP-
Exception>
• Search CPAN
https://metacpan.org/release/HTTP-Exception <https://metacpan.org/release/HTTP-
Exception>
LICENSE AND COPYRIGHT
Copyright 2010 Thomas Mueller.
This program is free software; you can redistribute it and/or modify it under the terms of
either: the GNU General Public License as published by the Free Software Foundation; or
the Artistic License.
See http://dev.perl.org/licenses/ for more information.