Class::Exporter(3pm)

1Class::Exporter(3)    User Contributed Perl Documentation   Class::Exporter(3)
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NAME

6       Class::Exporter - Export class methods as regular subroutines
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SYNOPSIS

9         package MagicNumber;
10         use base 'Class::Exporter';
11
12         # Export object-oriented methods!
13         @EXPORT_OK       = qw(magic_number);
14
15         sub new {
16           my $class = shift;
17           bless { magic_number=>3, @_ }, $class
18         }
19
20         sub magic_number {
21           my $self = shift;
22           @_ and $self->{magic_number} = shift;
23           $self->{magic_number}
24         }
25
26         # Meanwhile, in another piece of code!
27         package Bar;
28         use MagicNumber;  # exports magic_number
29         print magic_number; # prints 3
30         magic_number(7);
31         print magic_number; # prints 7
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33         # Each package gets its own instance of the object. This ensures that
34         # two packages both using your module via import semantics don't mess
35         # with each other.
36
37         package Baz;
38         use MagicNumber; # exports magic_number
39         print magic_number; # prints 3 because this package has a different
40                             # MagicNumber object than package Bar.
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DESCRIPTION

43       This module makes it much easier to make a module have a hybrid
44       object/method interface similar to the one of CGI.pm. You can take any
45       old module that has an object- oriented interface and convert it to
46       have a hybrid interface by simply adding "use base 'Class::Exporter'"
47       to your code.
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49       This package allows you to export object methods. It supports
50       "import()", @EXPORT and @EXPORT_OK and not a whole lot else. Each
51       package into which your object methods are imported gets its own
52       instance of the object.  This ensures that there are no interaction
53       effects between multiple packages that use your object.
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55       Setting up a module to export its variables and functions is simple:
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57           package My::Module;
58           use base 'Class::Exporter';
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60           @EXPORT = qw($Foo bar);
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62       now when you "use My::Module", $Foo and "bar()" will show up.
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64       In order to make exporting optional, use @EXPORT_OK.
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66           package My::Module;
67           use base 'Class::Exporter';
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69           @EXPORT_OK = qw($Foo bar);
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71       when My::Module is used, $Foo and "bar()" will not show up.  You have
72       to ask for them.  "use My::Module qw($Foo bar)".
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Methods

75       Class::Exporter has one public method, import(), which is called
76       automatically when your modules is use()'d.
77
78       In normal usage you don't have to worry about this at all.
79
80       import
81             Some::Module->import;
82             Some::Module->import(@symbols);
83
84           Works just like "Exporter::import()" excepting it only honors
85           @Some::Module::EXPORT and @Some::Module::EXPORT_OK.
86
87           The given @symbols are exported to the current package provided
88           they are in @Some::Module::EXPORT or @Some::Module::EXPORT_OK.
89           Otherwise an exception is thrown (ie. the program dies).
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91           If @symbols is not given, everything in @Some::Module::EXPORT is
92           exported.
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DIAGNOSTICS

95       '"%s" is not exported by the %s module'
96           Attempted to import a symbol which is not in @EXPORT or @EXPORT_OK.
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98       'Can\'t export symbol: %s'
99           Attempted to import a symbol of an unknown type (ie. the leading
100           $@% salad wasn't recognized).
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AUTHORS

103       David James <david@jamesgang.com>
104
105       Most of the code and documentation was borrowed from Exporter::Lite.
106       Exporter::Lite was written by Michael G Schwern <schwern@pobox.com>
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LICENSE

112         Copyright (c) 2002 David James
113         All rights reserved.
114         This program is free software; you can redistribute it and/or
115         modify it under the same terms as Perl itself.
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119perl v5.28.1                      2003-04-13                Class::Exporter(3)