Sub::WrapPackages - add pre- and post-execution wrappers around all the subroutines in packages or around individual subs
use Sub::WrapPackages (
packages => [qw(Foo Bar)], # wrap all Foo::* and Bar::*
subs => [qw(Baz::a, Baz::b)], # wrap these two subs as well
wrap_inherited => 1, # and wrap any methods
# inherited by Foo and Bar
pre => sub {
print "called $_[0] with params ".
join(', ', @_[1..$#_])."\n";
},
post => sub {
print "$_[0] returned $_[1]\n";
},
This is mostly a wrapper around Damian Conway's Hook::LexWrap module. Please go and read the docs for that module now. The differences are:
We don't export a wrap() function, instead preferring to do all the magic when you use this module. We just wrap named subroutines, no references. I didn't need that functionality so although it's probably available if you look at the source I haven't tested it. Patches welcome!
In the synopsis above, you will see two named parameters, subs and packages. Any subroutine mentioned in subs will be wrapped. Any packages mentioned in packages will have all their subroutines wrapped.
In conjunction with the packages arrayref, this wraps all calls to inherited methods made through those packages. If you call those methods directly in the superclass then they are not affected.
I threw Damian's ideas out of the window. Instead, your pre-wrapper will be passed the wrapped subroutine's name, and all the parameters to be passed to it. Who knows what will happen if you modify those params, I don't need that so haven't tested it. Patches welcome!
The post-wrapper will be passed the wrapped subroutine's name, and a single parameter for the return value(s) as in Damian's module. Figuring out the difference between returning an array and returning a reference to an array is left as an exercise for the interested reader.
Wrapped subroutines may cause perl 5.6.1, and maybe other versions, to segfault when called in void context. I believe this is a bug in Hook::LexWrap.
I say "patches welcome" a lot.
AUTOLOAD and DESTROY are not treated as being special.
I like to know who's using my code. All comments, including constructive criticism, are welcome. Please email me.
David Cantrell <david@cantrell.org.uk>
Thanks also to Adam Trickett who thought this was a jolly good idea, Tom Hukins who prompted me to add support for inherited methods, and Ed Summers, whose code for figgering out what functions a package contains I borrowed out of Acme::Voodoo.
Thanks to Tom Hukins for sending in a test case for the situation when a class and a subclass are both defined in the same file.
Copyright 2003 - 2006 David Cantrell
This module is free-as-in-speech software, and may be used, distributed, and modified under the same terms as Perl itself.
