http://search.cpan.org/~jrockway/Catalyst-Manual-5.701003/lib/Catalyst/Manual/Tutorial/CatalystBasics.pod#DATABASE_ACCESS_WITH_DBIx::Class

在看到catalyst manual tutorial的时候，作者还是给出了解释

Note: Catalyst actions are regular Perl methods, but they make use of Nicholas Clark's attributes module (that's the : Local next to the sub list in the code above) to provide additional information to the Catalyst dispatcher logic.

对于catalyst中方法的attr在manual intro文档里边有详细描述

下边地址有更基本的描述：
http://search.cpan.org/~nwclark/perl-5.8.8/pod/perlsub.pod#Subroutine_Attributes___

也没时间很详细的研究，先记录一下