6 Moose::Cookbook::WTF - For when things go wrong with Moose
12 =head3 Why is my code taking so long to load?
14 Moose has a fairly heavy compile time burden, which it
15 inherits from Class::MOP. If load/compile time is a
16 concern for your application, Moose may not be the
19 Although, you should note that we are exploring the
20 use of L<Module::Compile> to try and reduce this problem,
21 but nothing is ready yet.
23 =head3 Why are my objects taking so long to construct?
25 Moose uses a lot of introspection when constructing an
26 instance, and introspection can be slow. This problem
27 can be solved by making your class immutable. This can
28 be done with the following code:
30 MyClass->meta->make_immutable();
32 Moose will then memoize a number of meta-level methods
33 and inline a constructor for you. For more information
34 on this see the L<Constructors> section below and in the
35 L<Moose::Cookbook::FAQ>.
37 =head2 Constructors & Immutability
39 =head3 I made my class immutable, but C<new> it is still slow!
41 Do you have a custom C<new> method in your class? Moose
42 will not overwrite your custom C<new> method, you would
43 probably do better to try and convert this to use the
44 C<BUILD> method or possibly set C<default> values in
45 the attribute declaration.
47 =head3 I made my class immutable, and now my (before | after | around) C<new> is not being called?
49 Making a I<before>, I<after> or I<around> wrap around the
50 C<new> method, will actually create a C<new> method within
51 your class. This will prevent Moose from creating one itself
52 when you make the class immutable.
56 =head3 I created an attribute, where are my accessors?
58 Accessors are B<not> created implicitly, you B<must> ask Moose
59 to create them for you. My guess is that you have this:
61 has 'foo' => (isa => 'Bar');
63 when what you really want to say is:
65 has 'foo' => (isa => 'Bar', is => 'rw');
67 The reason this is so, is because it is a perfectly valid use
68 case to I<not> have an accessor. The simplest one is that you
69 want to write your own. If Moose created on automatically, then
70 because of the order in which classes are constructed, Moose
71 would overwrite your custom accessor. You wouldn't want that
74 =head2 Method Modfiers
76 =head3 How come I can't change C<@_> in a C<before> modifier?
78 The C<before> modifier simply is called I<before> the main method.
79 Its return values are simply ignored, and are B<not> passed onto
82 There are a number of reasons for this, but those arguments are
83 too lengthy for this document. Instead, I suggest using an C<around>
84 modifier instead. Here is some sample code:
88 my ($self, @args) = @_;
89 # do something silly here to @args
90 $next->($self, reverse(@args));
93 =head3 How come I can't see return values in an C<after> modifier?
95 As with the C<before> modifier, the C<after> modifier is simply
96 called I<after> the main method. It is passed the original contents
97 of C<@_> and B<not> the return values of the main method.
99 Again, the arguments are too lengthy as to why this has to be. And
100 as with C<before> I recommend using an C<around> modifier instead.
101 Here is some sample code:
103 around 'foo' => sub {
105 my ($self, @args) = @_;
106 my @rv = $next->($self, @args);
107 # do something silly with the return values
113 Stevan Little E<lt>stevan@iinteractive.comE<gt>
115 =head1 COPYRIGHT AND LICENSE
117 Copyright 2006, 2007 by Infinity Interactive, Inc.
119 L<http://www.iinteractive.com>
121 This library is free software; you can redistribute it and/or modify
122 it under the same terms as Perl itself.