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1 | =pod |
2 | |
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3 | =head1 NAME |
4 | |
5 | Moose::Manual::BestPractices - Get the most out of Moose |
6 | |
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7 | =head1 RECOMMENDATIONS |
8 | |
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9 | Moose has a lot of features, and there's definitely more than one way |
10 | to do it. However, we think that picking a subset of these features |
11 | and using them consistently makes everyone's life easier. |
12 | |
13 | Of course, as with any list of "best practices", these are really just |
14 | opinions. Feel free to ignore us. |
15 | |
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16 | =head2 C<no Moose> and immutabilize |
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17 | |
18 | We recommend that you end your Moose class definitions by removing the |
19 | Moose sugar and making your class immutable. |
20 | |
21 | package Person; |
22 | |
23 | use Moose; |
24 | |
25 | # extends, roles, attributes, etc. |
26 | |
27 | # methods |
28 | |
29 | no Moose; |
30 | |
31 | __PACKAGE__->meta->make_immutable; |
32 | |
33 | 1; |
34 | |
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35 | The C<no Moose> bit is simply good code hygiene, and making classes |
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36 | immutable speeds up a lot of things, most notably object construction. |
37 | |
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38 | =head2 Always call C<SUPER::BUILDARGS> |
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39 | |
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40 | If you override the C<BUILDARGS> method in your class, make sure to |
41 | play nice and call C<SUPER::BUILDARGS> to handle cases you're not |
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42 | checking for explicitly. |
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43 | |
44 | The default C<BUILDARGS> method in L<Moose::Object> handles both a |
45 | list and hashref of named parameters correctly, and also checks for a |
46 | I<non-hashref> single argument. |
47 | |
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48 | =head2 Don't use the C<initializer> feature |
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49 | |
50 | Don't know what we're talking about? That's fine. |
51 | |
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52 | =head2 Use C<builder> instead of C<default> most of the time |
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53 | |
54 | Builders can be inherited, they have explicit names, and they're just |
55 | plain cleaner. |
56 | |
57 | However, I<do> use a default when the default is a non-reference, |
58 | I<or> when the default is simply an empty reference of some sort. |
59 | |
60 | Also, keep your builder methods private. |
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61 | |
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62 | =head2 Use C<lazy_build> |
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63 | |
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64 | Lazy is good, and often solves initialization ordering problems. It's |
65 | also good for deferring work that may never have to be done. If you're |
66 | going to be lazy, use I<lazy_build> to save yourself some typing and |
67 | standardize names. |
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68 | |
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69 | =head2 Consider keeping clearers and predicates private |
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70 | |
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71 | Does everyone I<really> need to be able to clear an attribute? |
72 | Probably not. Don't expose this functionality outside your class |
73 | by default. |
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74 | |
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75 | Predicates are less problematic, but there's no reason to make your |
76 | public API bigger than it has to be. |
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77 | |
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78 | =head2 Default to read-only, and consider keeping writers private |
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79 | |
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80 | Making attributes mutable just means more complexity to account for in |
81 | your program. The alternative to mutable state is to encourage users |
82 | of your class to simply make new objects as needed. |
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83 | |
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84 | If you I<must> make an attribute read-write, consider making the |
85 | writer a separate private method. Narrower APIs are easy to maintain, |
86 | and mutable state is trouble. |
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87 | |
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88 | =head2 Think twice before changing an attribute's type in a subclass |
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89 | |
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90 | Down this path lies great confusion. If the attribute is an object |
91 | itself, at least make sure that it has the same interface as the type |
92 | of object in the parent class. |
93 | |
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94 | =head2 Use L<MooseX::AttributeHelpers> instead of C<auto_deref> |
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95 | |
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96 | The C<auto_deref> feature is a bit troublesome. Directly exposing a |
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97 | complex attribute is ugly. Instead, consider using |
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98 | L<MooseX::AttributeHelpers> to define an API that exposes those pieces |
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99 | of functionality that need exposing. Then you can expose just the |
100 | functionality that you want. |
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101 | |
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102 | =head2 Always call C<inner> in the most specific subclass |
103 | |
104 | When using C<augment> and C<inner>, we recommend that you call |
105 | C<inner> in the most specific subclass of your hierarchy. This makes |
106 | it possible to subclass further and extend the hierarchy without |
107 | changing the parents. |
108 | |
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109 | =head2 Namespace your types |
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110 | |
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111 | Use some sort of namespacing convention for type names. We recommend |
112 | something like "MyApp.Type.Foo". I<Never> use "::" as the namespace |
113 | separator, since that overlaps with actual class names. |
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114 | |
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115 | =head2 Coercion instead of unions |
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116 | |
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117 | Consider using a type coercion instead of a type union. This was |
118 | covered at length in L<Moose::Manual::Types>. |
119 | |
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120 | =head2 Define all your types in one module |
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121 | |
122 | Define all your types and coercions in one module. This was also |
123 | covered in L<Moose::Manual::Types>. |
124 | |
125 | =head1 AUTHOR |
126 | |
127 | Dave Rolsky E<lt>autarch@urth.orgE<gt> |
128 | |
129 | =head1 COPYRIGHT AND LICENSE |
130 | |
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131 | Copyright 2009 by Infinity Interactive, Inc. |
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132 | |
133 | L<http://www.iinteractive.com> |
134 | |
135 | This library is free software; you can redistribute it and/or modify |
136 | it under the same terms as Perl itself. |
137 | |
138 | =cut |