1Sub::WrapPackages(3) User Contributed Perl Documentation Sub::WrapPackages(3)
2
6 Sub::WrapPackages - add pre- and post-execution wrappers around all the
7 subroutines in packages or around individual subs
8
10 use Sub::WrapPackages
11 packages => [qw(Foo Bar Baz::*)], # wrap all subs in Foo and Bar
12 # and any Baz::* packages
13 subs => [qw(Barf::a, Barf::b)], # wrap these two subs as well
14 wrap_inherited => 1, # and wrap any methods
15 # inherited by Foo, Bar, or
16 # Baz::*
17 except => qr/::w[oi]bble$/, # but don't wrap any sub called
18 # wibble or wobble
19 pre => sub {
20 print "called $_[0] with params ".
21 join(', ', @_[1..$#_])."\n";
22 },
23 post => sub {
24 print "$_[0] returned $_[1]\n";
25 };
26
28 While this module does broadly the same job as the 1.x versions did,
29 the interface may have changed incompatibly. Sorry. Hopefully it'll
30 be more maintainable and slightly less crazily magical. Also, caller()
31 should now work properly, ignoring wrappings.
32
34 This module installs pre- and post- execution subroutines for the
35 subroutines or packages you specify. The pre-execution subroutine is
36 passed the wrapped subroutine's name and all its arguments. The post-
37 execution subroutine is passed the wrapped sub's name and its results.
38 The return values from the pre- and post- subs are ignored, and they
40 are called in the same context (void, scalar or list) as the calling
41 code asked for.
42 Normal usage is to pass a bunch of parameters when the module is used.
44 However, you can also call Sub::WrapPackages::wrapsubs with the same
45 parameters.
46
48 Either pass parameters on loading the module, as above, or pass them to
49 ...
50 the wrapsubs subroutine
52 the subs arrayref
53 In the synopsis above, you will see two named parameters, "subs"
54 and "packages". Any subroutine mentioned in "subs" will be
55 wrapped. Any subroutines mentioned in 'subs' must already exist -
56 ie their modules must be loaded - at the time you try to wrap them.
57 the packages arrayref
59 Any package mentioned here will have all its subroutines wrapped,
60 including any that it imports at load-time. Packages can be loaded
61 in any order - they don't have to already be loaded for
62 Sub::WrapPackages to work its magic.
63 You can specify wildcard packages. Anything ending in ::* is
65 assumed to be such. For example, if you specify Orchard::Tree::*,
66 then that matches Orchard::Tree, Orchard::Tree::Pear,
67 Orchard::Apple::KingstonBlack etc, but not - of course - Pine::Tree
68 or My::Orchard::Tree.
69 Note, however, that if a module exports a subroutine at load-time
71 using "import" then that sub will be wrapped in the exporting
72 module but not in the importing module. This is because import()
73 runs before we get a chance to fiddle with things. Sorry.
74 Deferred wrapping of subs in packages that aren't yet loaded works
76 via a subroutine inserted in @INC. This means that if you mess
77 around with @INC, eg by inserting a directoy at the beginning of
78 the path, the magic might not get a chance to run. If you "use
79 lib" to mess with @INC though, it should work, as I've over-ridden
80 lib's import() method. That said, code this funky has no right to
81 work. Use with caution!
82 wrap_inherited
84 In conjunction with the "packages" arrayref, this wraps all calls
85 to inherited methods made through those packages. If you call
86 those methods directly in the superclass then they are not affected
87 - unless they're wrapped in the superclass of course.
88 pre and post
90 References to the subroutines you want to use as wrappers.
91 except
93 A regex, any subroutine whose fully-qualified name (ie including
94 the package name) matches this will not be wrapped.
95 debug
97 This exists, but probably isn't of much use unless you want to hack
98 on Sub::WrapPackage's guts.
99
101 AUTOLOAD and DESTROY are not treated as being special. I'm not sure
102 whether they should be or not.
103 If you use wrap_inherited but classes change their inheritance tree at
105 run-time, then very bad things will happen. VERY BAD THINGS. So don't
106 do that. You shouldn't be doing that anyway. Mind you, you shouldn't
107 be doing the things that this module does either. BAD PROGRAMMER, NO
108 BIKKIT!
109 Bug reports should be made on Github or by email.
111
113 I like to know who's using my code. All comments, including
114 constructive criticism, are welcome. Please email me.
115
117 <git://github.com/DrHyde/perl-modules-Sub-WrapPackages.git>
118
120 Copyright 2003-2009 David Cantrell <david@cantrell.org.uk>
121 This software is free-as-in-speech software, and may be used,
123 distributed, and modified under the terms of either the GNU General
124 Public Licence version 2 or the Artistic Licence. It's up to you which
125 one you use. The full text of the licences can be found in the files
126 GPL2.txt and ARTISTIC.txt, respectively.
127
129 Thanks to Tom Hukins for sending in a test case for the situation when
130 a class and a subclass are both defined in the same file, and for
131 prompting me to support inherited methods;
132 to Dagfinn Ilmari Mannsaker for help with the craziness for fiddling
134 with modules that haven't yet been loaded;
135 to Lee Johnson for reporting a bug caused by perl 5.10's constant.pm
137 being Far Too Clever, and providing a patch and test;
138 to Adam Trickett who thought this was a jolly good idea;
140 to Ed Summers, whose code for figgering out what functions a package
142 contains I borrowed out of Acme::Voodoo;
143 and to Yanick Champoux for numerous readability improvements.
145perl v5.28.0 2017-10-25 Sub::WrapPackages(3)