1 .\" Automatically generated by Pod::Man v1.37, Pod::Parser v1.3
4 .\" ========================================================================
5 .de Sh \" Subsection heading
13 .de Sp \" Vertical space (when we can't use .PP)
17 .de Vb \" Begin verbatim text
22 .de Ve \" End verbatim text
26 .\" Set up some character translations and predefined strings. \*(-- will
27 .\" give an unbreakable dash, \*(PI will give pi, \*(L" will give a left
28 .\" double quote, and \*(R" will give a right double quote. | will give a
29 .\" real vertical bar. \*(C+ will give a nicer C++. Capital omega is used to
30 .\" do unbreakable dashes and therefore won't be available. \*(C` and \*(C'
31 .\" expand to `' in nroff, nothing in troff, for use with C<>.
33 .ds C+ C\v'-.1v'\h'-1p'\s-2+\h'-1p'+\s0\v'.1v'\h'-1p'
37 . if (\n(.H=4u)&(1m=24u) .ds -- \(*W\h'-12u'\(*W\h'-12u'-\" diablo 10 pitch
38 . if (\n(.H=4u)&(1m=20u) .ds -- \(*W\h'-12u'\(*W\h'-8u'-\" diablo 12 pitch
51 .\" If the F register is turned on, we'll generate index entries on stderr for
52 .\" titles (.TH), headers (.SH), subsections (.Sh), items (.Ip), and index
53 .\" entries marked with X<> in POD. Of course, you'll have to process the
54 .\" output yourself in some meaningful fashion.
57 . tm Index:\\$1\t\\n%\t"\\$2"
63 .\" For nroff, turn off justification. Always turn off hyphenation; it makes
64 .\" way too many mistakes in technical documents.
68 .\" Accent mark definitions (@(#)ms.acc 1.5 88/02/08 SMI; from UCB 4.2).
69 .\" Fear. Run. Save yourself. No user-serviceable parts.
70 . \" fudge factors for nroff and troff
79 . ds #H ((1u-(\\\\n(.fu%2u))*.13m)
85 . \" simple accents for nroff and troff
95 . ds ' \\k:\h'-(\\n(.wu*8/10-\*(#H)'\'\h"|\\n:u"
96 . ds ` \\k:\h'-(\\n(.wu*8/10-\*(#H)'\`\h'|\\n:u'
97 . ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'^\h'|\\n:u'
98 . ds , \\k:\h'-(\\n(.wu*8/10)',\h'|\\n:u'
99 . ds ~ \\k:\h'-(\\n(.wu-\*(#H-.1m)'~\h'|\\n:u'
100 . ds / \\k:\h'-(\\n(.wu*8/10-\*(#H)'\z\(sl\h'|\\n:u'
102 . \" troff and (daisy-wheel) nroff accents
103 .ds : \\k:\h'-(\\n(.wu*8/10-\*(#H+.1m+\*(#F)'\v'-\*(#V'\z.\h'.2m+\*(#F'.\h'|\\n:u'\v'\*(#V'
104 .ds 8 \h'\*(#H'\(*b\h'-\*(#H'
105 .ds o \\k:\h'-(\\n(.wu+\w'\(de'u-\*(#H)/2u'\v'-.3n'\*(#[\z\(de\v'.3n'\h'|\\n:u'\*(#]
106 .ds d- \h'\*(#H'\(pd\h'-\w'~'u'\v'-.25m'\f2\(hy\fP\v'.25m'\h'-\*(#H'
107 .ds D- D\\k:\h'-\w'D'u'\v'-.11m'\z\(hy\v'.11m'\h'|\\n:u'
108 .ds th \*(#[\v'.3m'\s+1I\s-1\v'-.3m'\h'-(\w'I'u*2/3)'\s-1o\s+1\*(#]
109 .ds Th \*(#[\s+2I\s-2\h'-\w'I'u*3/5'\v'-.3m'o\v'.3m'\*(#]
110 .ds ae a\h'-(\w'a'u*4/10)'e
111 .ds Ae A\h'-(\w'A'u*4/10)'E
112 . \" corrections for vroff
113 .if v .ds ~ \\k:\h'-(\\n(.wu*9/10-\*(#H)'\s-2\u~\d\s+2\h'|\\n:u'
114 .if v .ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'\v'-.4m'^\v'.4m'\h'|\\n:u'
115 . \" for low resolution devices (crt and lpr)
116 .if \n(.H>23 .if \n(.V>19 \
129 .\" ========================================================================
131 .IX Title "Moose::Cookbook::Extending::Recipe3 3"
132 .TH Moose::Cookbook::Extending::Recipe3 3 "2009-05-01" "perl v5.8.7" "User Contributed Perl Documentation"
134 Moose::Cookbook::Extending::Recipe3 \- Providing an alternate base object class
136 .IX Header "SYNOPSIS"
138 \& package MyApp::Base;
143 \& extends 'Moose::Object';
147 \& before 'new' => sub { warn "Making a new " . $_[0] };
155 \& package MyApp::UseMyBase;
157 \& use Moose::Exporter;
161 \& Moose::Exporter\->setup_import_methods( also => 'Moose' );
167 \& return Moose\->init_meta( @_, base_class => 'MyApp::Base' );
171 .IX Header "DESCRIPTION"
172 A common extension is to provide an alternate base class. One way to
173 do that is to make a \f(CW\*(C`MyApp::base\*(C'\fR and add \f(CW\*(C`extends\ 'MyApp::Base'\*(C'\fR to every class in your application. That's pretty
174 tedious. Instead, you can create a Moose-alike module that sets the
175 base object class to \f(CW\*(C`MyApp::Base\*(C'\fR for you.
177 Then, instead of writing \f(CW\*(C`use\ Moose\*(C'\fR you can write \f(CW\*(C`use\ MyApp::UseMyBase\*(C'\fR.
179 In this particular example, our base class issues some debugging
180 output every time a new object is created, but you can think of some
181 more interesting things to do with your own base class.
183 This uses the magic of Moose::Exporter. When we call \f(CW\*(C`Moose::Exporter\->setup_import_methods( also => 'Moose' )\*(C'\fR it builds
184 \&\f(CW\*(C`import\*(C'\fR and \f(CW\*(C`unimport\*(C'\fR methods for you. The \f(CW\*(C`also => 'Moose'\*(C'\fR
185 bit says that we want to export everything that Moose does.
187 The \f(CW\*(C`import\*(C'\fR method that gets created will call our \f(CW\*(C`init_meta\*(C'\fR
188 method, passing it \f(CW\*(C`for_caller => $caller\*(C'\fR as its
189 arguments. The \f(CW$caller\fR is set to the class that actually imported
190 us in the first place.
192 See the Moose::Exporter docs for more details on its \s-1API\s0.
193 .SH "USING MyApp::UseMyBase"
194 .IX Header "USING MyApp::UseMyBase"
195 To actually use our new base class, we simply use \f(CW\*(C`MyApp::UseMyBase\*(C'\fR
196 \&\fIinstead\fR of \f(CW\*(C`Moose\*(C'\fR. We get all the Moose sugar plus our new base
204 \& use MyApp::UseMyBase;
208 \& has 'size' => ( is => 'rw' );
212 \& no MyApp::UseMyBase;
215 .IX Header "CONCLUSION"
216 This is an awful lot of magic for a simple base class. You will often
217 want to combine a metaclass trait with a base class extension, and
218 that's when this technique is useful.
221 Dave Rolsky <autarch@urth.org>
222 .SH "COPYRIGHT AND LICENSE"
223 .IX Header "COPYRIGHT AND LICENSE"
224 Copyright 2006\-2009 by Infinity Interactive, Inc.
226 <http://www.iinteractive.com>
228 This library is free software; you can redistribute it and/or modify
229 it under the same terms as Perl itself.