NAME
MooseX::Unique - Make your Moose instances as unique as you are
VERSION
This document describes v0.005 of MooseX::Unique - released June 22, 2011 as part of MooseX-Unique.
SYNOPSIS
package MyApp;
use Moose;
use MooseX::Unique;
has identity => (
is => 'ro',
isa => 'Str',
required => 1,
unique => 1,
);
has number => (
is => 'rw',
isa => 'Int'
);
package main;
use Modern::Perl;
my $objecta = MyApp->new_or_matching(identity => 'Mine');
my $objectb = MyApp->new_or_matching(identity => 'Mine');
$objecta->number(40);
# prints: Num: 40
say "Num: ", $objectb->number;
DESCRIPTION
This module uses MooseX::InstanceTracking to keep track of your
instances. If an attribute has a unique flag set, and a new attribute is
requested with the same value, the original will be returned.
This is useful if
* If you are creating several attributes from data, which may have
duplicates that you would rather merge than replace.
* If you want to create a new or modify and are too lazy to look up
the data yourself.
* You have a complicated network of data, with several cross
references. For example, a song could have an album and an artist.
That album could have the same artist, or a different artist. That
artist can have multiple albums. That album, of course, has multiple
songs. When importing song by song, this web would be lost without
some sort of instance tracking. This module lets Moose do the work
for you.
That having all been said, think twice before using this module. It can
cause spooky action at a distance. Be sure to use it only on immutable
objects. The synopsis should indicate how this can be troubling,
confusing, and a great source of bizarre bugs if you are not paying
attention.
In addition to the spooky action at a distance, please keep in mind that
the instance tracking is performed using weak references. If you let an
object fall out of scope, it is gone, so a new object with the same
unique attribute will be new.
METHODS
new_or_matching(%params)
Provided by MooseX::Unique::Object.
This is a wrapper around your new method that looks up the attribute for
you. Please note that this module does not process your BUILDARGS before
looking for an instance. So, values must be passed as a hash or hash
reference. Any attribute that is not flagged as unique will be ignored
in the case of an existing instance.
FUNCTIONS
unique($attr)
Sugar method that can be used instead of attribute labeling. Set $attr
to the name of an attribute and it will be unique.
This can be used in a role even if the attribute is not defined in the
role.
required_matches($int)
Sugar method that sets the minimum number of matches required to make a
match. The default is 1. Setting this to 0 means that a match requires
that all attributes set to unique are matched. If you run this more than
once, for example in a role, it will add to the existing unless the
existing is 0. If you set it to 0, it will reset it to 0 regardless of
current value.
BUGS
I'm sure there are a few in the shadows. Please submit test cases to the
bug tracker web link above.
ACKNOWLEDGMENTS
Thanks to Jesse (doy) Luehrs for steering me clear of bad code design.
Thanks to Shawn (sartak) Moore for MooseX::InstanceTracking.
And thanks to the rest of the Moose team for Moose.
SEE ALSO
Please see those modules/websites for more information related to this
module.
* MooseX::InstanceTracking
SUPPORT
Websites
The following websites have more information about this module, and may
be of help to you. As always, in addition to those websites please use
your favorite search engine to discover more resources.
* Search CPAN
The default CPAN search engine, useful to view POD in HTML format.
<http://search.cpan.org/dist/MooseX-Unique>
* CPAN Testers Dependencies
The CPAN Testers Dependencies is a website that shows a chart of the
test results of all dependencies for a distribution.
<http://deps.cpantesters.org/?module=MooseX::Unique>
* CPANTS
The CPANTS is a website that analyzes the Kwalitee ( code metrics )
of a distribution.
<http://cpants.perl.org/dist/overview/MooseX-Unique>
* CPAN Testers
The CPAN Testers is a network of smokers who run automated tests on
uploaded CPAN distributions.
<http://www.cpantesters.org/distro/M/MooseX-Unique>
* CPAN Testers Matrix
The CPAN Testers Matrix is a website that provides a visual way to
determine what Perls/platforms PASSed for a distribution.
<http://matrix.cpantesters.org/?dist=MooseX-Unique>
Email
You can email the author of this module at "EALLENIII at cpan.org"
asking for help with any problems you have.
Bugs / Feature Requests
Please report any bugs or feature requests by email to
"bug-moosex-unique at rt.cpan.org", or through the web interface at
<http://rt.cpan.org/NoAuth/ReportBug.html?Queue=MooseX-Unique>. You will
be automatically notified of any progress on the request by the system.
Source Code
The code is open to the world, and available for you to hack on. Please
feel free to browse it and play with it, or whatever. If you want to
contribute patches, please send me a diff or prod me to pull from your
repository :)
<http://github.com/riemann42/MooseX-Unique>
git clone git://github.com/riemann42/MooseX-Unique.git
AUTHOR
Edward Allen <ealleniii@cpan.org>
COPYRIGHT AND LICENSE
This software is copyright (c) 2011 by Edward J. Allen III.
This is free software; you can redistribute it and/or modify it under
the same terms as the Perl 5 programming language system itself.
DISCLAIMER OF WARRANTY
BECAUSE THIS SOFTWARE IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY
FOR THE SOFTWARE, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN
OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES
PROVIDE THE SOFTWARE "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER
EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE
ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE SOFTWARE IS WITH
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NECESSARY SERVICING, REPAIR, OR CORRECTION.
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WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR
REDISTRIBUTE THE SOFTWARE AS PERMITTED BY THE ABOVE LICENCE, BE LIABLE
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