1 2=head1 NAME 3 4DBIx::Class::Manual::Component - Developing DBIx::Class Components 5 6=head1 WHAT IS A COMPONENT 7 8A component is a module that can be added in to your DBIx::Class 9classes to provide extra functionality. A good example is the PK::Auto 10component which automatically retrieves primary keys that the database 11itself creates, after the insert has happened. 12 13=head1 USING 14 15Components are loaded using the load_components() method within your 16DBIx::Class classes. 17 18 package My::Thing; 19 use base qw( DBIx::Class::Core ); 20 __PACKAGE__->load_components(qw/InflateColumn::DateTime TimeStamp/); 21 22Generally you do not want to specify the full package name 23of a component, instead take off the DBIx::Class:: part of 24it and just include the rest. If you do want to load a 25component outside of the normal namespace you can do so 26by prepending the component name with a +. 27 28 __PACKAGE__->load_components(qw/ +My::Component /); 29 30Once a component is loaded all of its methods, or otherwise, 31that it provides will be available in your class. 32 33The order in which is you load the components may be very 34important, depending on the component. If you are not sure, 35then read the docs for the components you are using and see 36if they mention anything about the order in which you should 37load them. 38 39=head1 CREATING COMPONENTS 40 41Making your own component is very easy. 42 43 package DBIx::Class::MyComp; 44 use base qw(DBIx::Class); 45 # Create methods, accessors, load other components, etc. 46 1; 47 48When a component is loaded it is included in the calling 49class' inheritance chain using L<Class::C3>. As well as 50providing custom utility methods, a component may also 51override methods provided by other core components, like 52L<DBIx::Class::Row> and others. For example, you 53could override the insert and delete methods. 54 55 sub insert { 56 my $self = shift; 57 # Do stuff with $self, like set default values. 58 return $self->next::method( @_ ); 59 } 60 61 sub delete { 62 my $self = shift; 63 # Do stuff with $self. 64 return $self->next::method( @_ ); 65 } 66 67Now, the order that a component is loaded is very important. Components 68that are loaded first are the first ones in the inheritance stack. So, if 69you override insert() but the DBIx::Class::Row component is loaded first 70then your insert() will never be called, since the DBIx::Class::Row insert() 71will be called first. If you are unsure as to why a given method is not 72being called try printing out the current linearized MRO. 73 74 print join ', ' => mro::get_linear_isa('YourClass::Name'); 75 76=head1 EXISTING COMPONENTS 77 78=head2 Extra 79 80These components provide extra functionality beyond 81basic functionality that you can't live without. 82 83L<DBIx::Class::CDBICompat> - Class::DBI Compatibility layer. 84 85L<DBIx::Class::FormTools> - Build forms with multiple interconnected objects. 86 87L<DBIx::Class::HTMLWidget> - Like FromForm but with DBIx::Class and HTML::Widget. 88 89L<DBIx::Class::Ordered> - Modify the position of objects in an ordered list. 90 91L<DBIx::Class::PK::Auto> - Retrieve automatically created primary keys upon insert. 92 93L<DBIx::Class::QueriesTime> - Display the amount of time it takes to run queries. 94 95L<DBIx::Class::RandomStringColumns> - Declare virtual columns that return random strings. 96 97L<DBIx::Class::UUIDColumns> - Implicit UUID columns. 98 99L<DBIx::Class::WebForm> - CRUD methods. 100 101=head2 Experimental 102 103These components are under development, their interfaces may 104change, they may not work, etc. So, use them if you want, but 105be warned. 106 107L<DBIx::Class::Validation> - Validate all data before submitting to your database. 108 109=head2 Core 110 111These are the components that all, or nearly all, people will use 112without even knowing it. These components provide most of 113DBIx::Class' functionality. 114 115L<DBIx::Class::Core> - Loads various components that "most people" would want. 116 117L<DBIx::Class::AccessorGroup> - Lets you build groups of accessors. 118 119L<DBIx::Class::DB> - Non-recommended classdata schema component. 120 121L<DBIx::Class::InflateColumn> - Automatically create objects from column data. 122 123L<DBIx::Class::PK> - This class contains methods for handling primary keys and methods depending on them. 124 125L<DBIx::Class::Relationship> - Inter-table relationships. 126 127L<DBIx::Class::ResultSourceProxy::Table> - Provides a classdata table object and method proxies. 128 129L<DBIx::Class::Row> - Basic row methods. 130 131=head1 SEE ALSO 132 133L<DBIx::Class::Manual::Cookbook> 134 135=head1 FURTHER QUESTIONS? 136 137Check the list of L<additional DBIC resources|DBIx::Class/GETTING HELP/SUPPORT>. 138 139=head1 COPYRIGHT AND LICENSE 140 141This module is free software L<copyright|DBIx::Class/COPYRIGHT AND LICENSE> 142by the L<DBIx::Class (DBIC) authors|DBIx::Class/AUTHORS>. You can 143redistribute it and/or modify it under the same terms as the 144L<DBIx::Class library|DBIx::Class/COPYRIGHT AND LICENSE>. 145