1Class::C3::Adopt::NEXT(U3s)er Contributed Perl DocumentatCiloanss::C3::Adopt::NEXT(3)
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NAME

6       Class::C3::Adopt::NEXT - make NEXT suck less
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SYNOPSIS

9           package MyApp::Plugin::FooBar;
10           #use NEXT;
11           use Class::C3::Adopt::NEXT;
12           # or 'use Class::C3::Adopt::NEXT -no_warn;' to suppress warnings
13
14           # Or use warnings::register
15           # no warnings 'Class::C3::Adopt::NEXT';
16
17           # Or suppress warnings in a set of modules from one place
18           # no Class::C3::Adopt::NEXT qw/ Module1 Module2 Module3 /;
19           # Or suppress using a regex
20           # no Class::C3::Adopt::NEXT qr/^Module\d$/;
21
22           sub a_method {
23               my ($self) = @_;
24               # Do some stuff
25
26               # Re-dispatch method
27               # Note that this will generate a warning the _first_ time the package
28               # uses NEXT unless you un comment the 'no warnings' line above.
29               $self->NEXT::method();
30           }
31

DESCRIPTION

33       NEXT was a good solution a few years ago, but isn't any more.  It's
34       slow, and the order in which it re-dispatches methods appears random at
35       times. It also encourages bad programming practices, as you end up with
36       code to re-dispatch methods when all you really wanted to do was run
37       some code before or after a method fired.
38
39       However, if you have a large application, then weaning yourself off
40       "NEXT" isn't easy.
41
42       This module is intended as a drop-in replacement for NEXT, supporting
43       the same interface, but using Class::C3 to do the hard work. You can
44       then write new code without "NEXT", and migrate individual source files
45       to use "Class::C3" or method modifiers as appropriate, at whatever pace
46       you're comfortable with.
47

WARNINGS

49       This module will warn once for each package using NEXT. It uses
50       warnings::register, and so can be disabled like by adding "no warnings
51       'Class::C3::Adopt::NEXT';" to each package which generates a warning,
52       or adding "use Class::C3::Adopt::NEXT -no_warn;", or disable multiple
53       modules at once by saying:
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55           no Class::C3::Adopt::NEXT qw/ Module1 Module2 Module3 /;
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57       somewhere before the warnings are first triggered. You can also setup
58       entire name spaces of modules which will not warn using a regex, e.g.
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60           no Class::C3::Adopt::NEXT qr/^Module\d$/;
61

MIGRATING

63   Current code using NEXT
64       You add "use MRO::Compat" to the top of a package as you start
65       converting it, and gradually replace your calls to "NEXT::method()"
66       with "maybe::next::method()", and calls to "NEXT::ACTUAL::method()"
67       with "next::method()".
68
69       Example:
70
71           sub yourmethod {
72               my $self = shift;
73
74               # $self->NEXT::yourmethod(@_); becomes
75               $self->maybe::next::method();
76           }
77
78           sub othermethod {
79               my $self = shift;
80
81               # $self->NEXT::ACTUAL::yourmethodname(); becomes
82               $self->next::method();
83           }
84
85       On systems with Class::C3::XS present, this will automatically be used
86       to speed up method re-dispatch. If you are running perl version 5.9.5
87       or greater then the C3 method resolution algorithm is included in perl.
88       Correct use of MRO::Compat as shown above allows your code to be
89       seamlessly forward and backwards compatible, taking advantage of native
90       versions if available, but falling back to using pure perl "Class::C3".
91
92   Writing new code
93       Use Moose and make all of your plugins Moose::Roles, then use method
94       modifiers to wrap methods.
95
96       Example:
97
98           package MyApp::Role::FooBar;
99           use Moose::Role;
100
101           before 'a_method' => sub {
102               my ($self) = @_;
103               # Do some stuff
104           };
105
106           around 'a_method' => sub {
107               my $orig = shift;
108               my $self = shift;
109               # Do some stuff before
110               my $ret = $self->$orig(@_); # Run wrapped method (or not!)
111               # Do some stuff after
112               return $ret;
113           };
114
115           package MyApp;
116           use Moose;
117
118           with 'MyApp::Role::FooBar';
119

CAVEATS

121       There are some inheritance hierarchies that it is possible to create
122       which cannot be resolved to a simple C3 hierarchy. In that case, this
123       module will fall back to using "NEXT". In this case a warning will be
124       emitted.
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126       Because calculating the MRO of every class every time "->NEXT::foo" is
127       used from within it is too expensive, runtime manipulations of @ISA are
128       prohibited.
129

FUNCTIONS

131       This module replaces "NEXT::AUTOLOAD" with it's own version. If
132       warnings are enabled then a warning will be emitted on the first use of
133       "NEXT" by each package.
134

SEE ALSO

136       MRO::Compat and Class::C3 for method re-dispatch and Moose for method
137       modifiers and roles.
138
139       NEXT for documentation on the functionality you'll be removing.
140

AUTHORS

142         Florian Ragwitz <rafl@debian.org>
143         Tomas Doran <bobtfish@bobtfish.net>
144

146       This software is copyright (c) 2010 by Florian Ragwitz.
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148       This is free software; you can redistribute it and/or modify it under
149       the same terms as the Perl 5 programming language system itself.
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153perl v5.12.0                      2010-05-07         Class::C3::Adopt::NEXT(3)
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