DBIx::Class::Manual::CUsernContributed Perl DDBIx::Class::Manual::Component(3)NAMEDBIx::Class::Manual::Component - Developing DBIx::Class Components
WHAT IS A COMPONENT
A component is a module that can be added in to your DBIx::Class
classes to provide extra functionality. A good example is the PK::Auto
component which automatically retrieves primary keys that the database
itself creates, after the insert has happened.
USING
Components are loaded using the load_components() method within your
DBIx::Class classes.
package My::Thing;
use base qw( DBIx::Class::Core );
__PACKAGE__->load_components(qw/InflateColumn::DateTime TimeStamp/);
Generally you do not want to specify the full package name of a
component, instead take off the DBIx::Class:: part of it and just
include the rest. If you do want to load a component outside of the
normal namespace you can do so by prepending the component name with a
+.
__PACKAGE__->load_components(qw/ +My::Component /);
Once a component is loaded all of it's methods, or otherwise, that it
provides will be available in your class.
The order in which is you load the components may be very important,
depending on the component. If you are not sure, then read the docs for
the components you are using and see if they mention anything about the
order in which you should load them.
CREATING COMPONENTS
Making your own component is very easy.
package DBIx::Class::MyComp;
use base qw(DBIx::Class);
# Create methods, accessors, load other components, etc.
1;
When a component is loaded it is included in the calling class'
inheritance chain using Class::C3. As well as providing custom utility
methods, a component may also override methods provided by other core
components, like DBIx::Class::Row and others. For example, you could
override the insert and delete methods.
sub insert {
my $self = shift;
# Do stuff with $self, like set default values.
return $self->next::method( @_ );
}
sub delete {
my $self = shift;
# Do stuff with $self.
return $self->next::method( @_ );
}
Now, the order that a component is loaded is very important.
Components that are loaded first are the first ones in the inheritance
stack. So, if you override insert() but the DBIx::Class::Row component
is loaded first then your insert() will never be called, since the
DBIx::Class::Row insert() will be called first. If you are unsure as
to why a given method is not being called try printing out the current
linearized MRO.
print join ', ' => mro::get_linear_isa('YourClass::Name');
EXISTING COMPONENTS
Extra
These components provide extra functionality beyond basic functionality
that you can't live without.
DBIx::Class::CDBICompat - Class::DBI Compatibility layer.
DBIx::Class::FormTools - Build forms with multiple interconnected
objects.
DBIx::Class::HTMLWidget - Like FromForm but with DBIx::Class and
HTML::Widget.
DBIx::Class::Ordered - Modify the position of objects in an ordered
list.
DBIx::Class::PK::Auto - Retrieve automatically created primary keys
upon insert.
DBIx::Class::QueriesTime - Display the amount of time it takes to run
queries.
DBIx::Class::RandomStringColumns - Declare virtual columns that return
random strings.
DBIx::Class::UUIDColumns - Implicit UUID columns.
DBIx::Class::WebForm - CRUD methods.
Experimental
These components are under development, their interfaces may change,
they may not work, etc. So, use them if you want, but be warned.
DBIx::Class::Validation - Validate all data before submitting to your
database.
Core
These are the components that all, or nearly all, people will use
without even knowing it. These components provide most of DBIx::Class'
functionality.
DBIx::Class::Core - Loads various components that "most people" would
want.
DBIx::Class::AccessorGroup - Lets you build groups of accessors.
DBIx::Class::DB - Non-recommended classdata schema component.
DBIx::Class::InflateColumn - Automatically create objects from column
data.
DBIx::Class::PK - This class contains methods for handling primary keys
and methods depending on them.
DBIx::Class::Relationship - Inter-table relationships.
DBIx::Class::ResultSourceProxy::Table - Provides a classdata table
object and method proxies.
DBIx::Class::Row - Basic row methods.
SEE ALSO
DBIx::Class::Manual::Cookbook
AUTHOR
Aran Clary Deltac <bluefeet@cpan.org>
perl v5.14.2 2012-01-22 DBIx::Class::Manual::Component(3)