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 it's 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 Class::C3 inheritance stack. 73 74 print join ', ' => Class::C3::calculateMRO('YourClass::Name'); 75 76Check out the L<Class::C3> docs for more information about inheritance. 77 78=head1 EXISTING COMPONENTS 79 80=head2 Extra 81 82These components provide extra functionality beyond 83basic functionality that you can't live without. 84 85L<DBIx::Class::Serialize::Storable> - Hooks for Storable freeze/thaw. 86 87L<DBIx::Class::CDBICompat> - Class::DBI Compatibility layer. 88 89L<DBIx::Class::FormTools> - Build forms with multiple interconnected objects. 90 91L<DBIx::Class::HTMLWidget> - Like FromForm but with DBIx::Class and HTML::Widget. 92 93L<DBIx::Class::Ordered> - Modify the position of objects in an ordered list. 94 95L<DBIx::Class::PK::Auto> - Retrieve automatically created primary keys upon insert. 96 97L<DBIx::Class::QueriesTime> - Display the amount of time it takes to run queries. 98 99L<DBIx::Class::RandomStringColumns> - Declare virtual columns that return random strings. 100 101L<DBIx::Class::UTF8Columns> - Force UTF8 (Unicode) flag on columns. 102 103L<DBIx::Class::UUIDColumns> - Implicit UUID columns. 104 105L<DBIx::Class::WebForm> - CRUD methods. 106 107=head2 Experimental 108 109These components are under development, their interfaces may 110change, they may not work, etc. So, use them if you want, but 111be warned. 112 113L<DBIx::Class::Validation> - Validate all data before submitting to your database. 114 115=head2 Core 116 117These are the components that all, or nearly all, people will use 118without even knowing it. These components provide most of 119DBIx::Class' functionality. 120 121L<DBIx::Class::Core> - Loads various components that "most people" would want. 122 123L<DBIx::Class::AccessorGroup> - Lets you build groups of accessors. 124 125L<DBIx::Class::DB> - Non-recommended classdata schema component. 126 127L<DBIx::Class::InflateColumn> - Automatically create objects from column data. 128 129L<DBIx::Class::PK> - This class contains methods for handling primary keys and methods depending on them. 130 131L<DBIx::Class::Relationship> - Inter-table relationships. 132 133L<DBIx::Class::ResultSourceProxy::Table> - Provides a classdata table object and method proxies. 134 135L<DBIx::Class::Row> - Basic row methods. 136 137=head1 SEE ALSO 138 139L<DBIx::Class::Manual::Cookbook> 140 141=head1 AUTHOR 142 143Aran Clary Deltac <bluefeet@cpan.org> 144