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1 | NAME |
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2 | namespace::clean - Keep imports and functions out of your namespace |
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3 | |
4 | VERSION |
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5 | 0.10 |
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6 | |
7 | SYNOPSIS |
8 | package Foo; |
9 | use warnings; |
10 | use strict; |
11 | |
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12 | use Carp qw(croak); # 'croak' will be removed |
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13 | |
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14 | sub bar { 23 } # 'bar' will be removed |
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15 | |
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16 | # remove all previously defined functions |
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17 | use namespace::clean; |
18 | |
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19 | sub baz { bar() } # 'baz' still defined, 'bar' still bound |
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20 | |
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21 | # begin to collection function names from here again |
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22 | no namespace::clean; |
23 | |
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24 | sub quux { baz() } # 'quux' will be removed |
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25 | |
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26 | # remove all functions defined after the 'no' unimport |
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27 | use namespace::clean; |
28 | |
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29 | # Will print: 'No', 'No', 'Yes' and 'No' |
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30 | print +(__PACKAGE__->can('croak') ? 'Yes' : 'No'), "\n"; |
31 | print +(__PACKAGE__->can('bar') ? 'Yes' : 'No'), "\n"; |
32 | print +(__PACKAGE__->can('baz') ? 'Yes' : 'No'), "\n"; |
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33 | print +(__PACKAGE__->can('quux') ? 'Yes' : 'No'), "\n"; |
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34 | |
35 | 1; |
36 | |
37 | DESCRIPTION |
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38 | Keeping packages clean |
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39 | When you define a function, or import one, into a Perl package, it will |
40 | naturally also be available as a method. This does not per se cause |
41 | problems, but it can complicate subclassing and, for example, plugin |
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42 | classes that are included via multiple inheritance by loading them as |
43 | base classes. |
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44 | |
45 | The "namespace::clean" pragma will remove all previously declared or |
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46 | imported symbols at the end of the current package's compile cycle. |
47 | Functions called in the package itself will still be bound by their |
48 | name, but they won't show up as methods on your class or instances. |
49 | |
50 | By unimporting via "no" you can tell "namespace::clean" to start |
51 | collecting functions for the next "use namespace::clean;" specification. |
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52 | |
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53 | You can use the "-except" flag to tell "namespace::clean" that you don't |
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54 | want it to remove a certain function or method. A common use would be a |
55 | module exporting an "import" method along with some functions: |
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56 | |
57 | use ModuleExportingImport; |
58 | use namespace::clean -except => [qw( import )]; |
59 | |
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60 | If you just want to "-except" a single sub, you can pass it directly. |
61 | For more than one value you have to use an array reference. |
62 | |
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63 | Explicitely removing functions when your scope is compiled |
64 | It is also possible to explicitely tell "namespace::clean" what packages |
65 | to remove when the surrounding scope has finished compiling. Here is an |
66 | example: |
67 | |
68 | package Foo; |
69 | use strict; |
70 | |
71 | # blessed NOT available |
72 | |
73 | sub my_class { |
74 | use Scalar::Util qw( blessed ); |
75 | use namespace::clean qw( blessed ); |
76 | |
77 | # blessed available |
78 | return blessed shift; |
79 | } |
80 | |
81 | # blessed NOT available |
82 | |
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83 | Moose |
84 | When using "namespace::clean" together with Moose you want to keep the |
85 | installed "meta" method. So your classes should look like: |
86 | |
87 | package Foo; |
88 | use Moose; |
89 | use namespace::clean -except => 'meta'; |
90 | ... |
91 | |
92 | Same goes for Moose::Role. |
93 | |
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94 | METHODS |
95 | You shouldn't need to call any of these. Just "use" the package at the |
96 | appropriate place. |
97 | |
98 | import |
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99 | Makes a snapshot of the current defined functions and installs a |
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100 | B::Hooks::EndOfScope hook in the current scope to invoke the cleanups. |
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101 | |
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102 | unimport |
103 | This method will be called when you do a |
104 | |
105 | no namespace::clean; |
106 | |
107 | It will start a new section of code that defines functions to clean up. |
108 | |
109 | get_class_store |
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110 | This returns a reference to a hash in a passed package containing |
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111 | information about function names included and excluded from removal. |
112 | |
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113 | get_functions |
114 | Takes a class as argument and returns all currently defined functions in |
115 | it as a hash reference with the function name as key and a typeglob |
116 | reference to the symbol as value. |
117 | |
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118 | IMPLEMENTATION DETAILS |
119 | This module works through the effect that a |
120 | |
121 | delete $SomePackage::{foo}; |
122 | |
123 | will remove the "foo" symbol from $SomePackage for run time lookups |
124 | (e.g., method calls) but will leave the entry alive to be called by |
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125 | already resolved names in the package itself. "namespace::clean" will |
126 | restore and therefor in effect keep all glob slots that aren't "CODE". |
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127 | |
128 | A test file has been added to the perl core to ensure that this |
129 | behaviour will be stable in future releases. |
130 | |
131 | Just for completeness sake, if you want to remove the symbol completely, |
132 | use "undef" instead. |
133 | |
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134 | SEE ALSO |
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135 | B::Hooks::EndOfScope |
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136 | |
137 | AUTHOR AND COPYRIGHT |
138 | Robert 'phaylon' Sedlacek "<rs@474.at>", with many thanks to Matt S |
139 | Trout for the inspiration on the whole idea. |
140 | |
141 | LICENSE |
142 | This program is free software; you can redistribute it and/or modify it |
143 | under the same terms as perl itself. |
144 | |