Ouch - Exceptions that don't hurt.
use Ouch; eval { ouch 404, 'File not found.'; }; if (kiss 404) { check_elsewhere(); } say $@; # These two lines do the say $@->message; # same thing.
Ouch provides a class for exception handling that doesn't require a lot of boilerplate, nor any up front definition. If Exception::Class is working for you, great! But if you want something that is faster, easier to use, requires less typing, and has no prereqs, but still gives you much of that same functionality, then Ouch is for you.
It really comes down to Carp isn't enough for me, and Exception::Class does what I want but makes me type way too much. Also, I tend to work on a lot of protocol-based systems that use error codes (HTTP, FTP, SMTP, JSON-RPC) rather than error classes, so that feels more natural to me. Consider the difference between these:
Ouch
use Ouch; ouch 404, 'File not found.', 'file';
Exception::Class
use Exception::Class ( 'FileNotFound' => { fields => [ 'code', 'field' ], }, ); FileNotFound->throw( error => 'File not found.', code => 404, field => 'file' );
And if you want to catch the exception you're looking at:
if (kiss 404) { # do something }
my $e; if ($e = Exception::Class->caught('FileNotFound')) { # do something }
Those differences may not seem like a lot, but over any substantial program with lots of exceptions it can become a big deal.
Most of the time, all you need to do is:
ouch $code, $message, $data; ouch -32700, 'Parse error.', $request; # JSON-RPC 2.0 error ouch 441, 'You need to specify an email address.', 'email'; # form processing error
You can also go long form if you prefer:
die Ouch->new($code, $message, $data);
Some nice sugar instead of using the object oriented interface.
ouch 2121, 'Did not do the big thing.';
An error code. An integer representing error type. Try to stick to codes used in whatever domain you happen to be working in. HTTP Status codes. JSON-RPC error codes, etc.
A human readable error message.
Optional. Anything you want to attach to the exception to help a developer catching it decide what to do. For example, if you're doing form processing, you might want this to be the name of the field that caused the exception.
Some nice sugar to trap an Ouch.
if (kiss $code) { # make it go }
The code you're looking for.
Optional. If you like you can pass the exception into kiss. If not, it will just use whatever is in $@. You might want to do this if you've saved the exception before running another eval, for example.
kiss
$@
eval
A little sugar to make exceptions human friendly. Returns a clean error message from any exception, including an Ouch.
File not found.
Rather than:
File not found. at /Some/File.pm line 63.
Optional. If you like you can pass the exception into bleep. If not, it will just use whatever is in $@.
bleep
Constructor for the object-oriented interface. Takes the same parameters as ouch.
ouch
Ouch->new($code, $message, $data);
Returns the scalar form of the error message:
Crap! at /Some/File.pm line 43.
Just as if you had done:
die 'Crap!';
ouch $code, 'Crap!';
Call this if you want the full stack trace that lead up to the ouch.
Returns a formatted hash reference of the exception, which can be useful for handing off to a serializer like JSON.
{ code => $code, message => $message, data => $data, }
Returns the code passed into the constructor.
code
Returns the messsage passed into the constructor.
messsage
Returns the data passed into the constructor.
data
http://github.com/rizen/Ouch
http://github.com/rizen/Ouch/issues
If you're looking for something lighter, check out Carp that ships with Perl. Or if you're looking for something heavier check out Exception::Class.
JT Smith <jt_at_plainblack_dot_com>
Ouch is Copyright 2011 Plain Black Corporation (http://www.plainblack.com) and is licensed under the same terms as Perl itself.
To install Ouch, copy and paste the appropriate command in to your terminal.
cpanm
cpanm Ouch
CPAN shell
perl -MCPAN -e shell install Ouch
For more information on module installation, please visit the detailed CPAN module installation guide.