KinoSearch::Util::Class - class building utility
This is a private class and the interface may change radically and without warning. Do not use it on its own.
package KinoSearch::SomePackage::SomeClass; use base qw( KinoSearch::Util::Class ); BEGIN { __PACKAGE__->init_instance_vars( # constructor params / members foo => undef, bar => {}, # members baz => {}, ); }
KinoSearch::Util::Class is a class-building utility a la Class::Accessor, Class::Meta, etc. It provides four main services:
A mechanism for inheriting instance variable declarations.
A constructor with basic argument checking.
Manufacturing of get_xxxx and set_xxxx methods.
Convenience methods which help in defining abstract classes.
The %instance_vars hash, which is always a package global, serves as a template for the creation of a hash-based object. It is built up from all the %instance_vars hashes in the module's parent classes, using init_instance_vars().
Key-value pairs in an %instance_vars hash are labeled as "constructor params" and/or "members". Items which are labeled as constructor params can be used as arguments to new().
BEGIN { __PACKAGE__->init_instance_vars( # constructor params / members foo => undef, bar => {}, # members baz => '', ); } # ok: specifies foo, uses default for bar, derives baz my $object = __PACKAGE__->new( foo => $foo ); # not ok: baz isn't a constructor param my $object = __PACKAGE__->new( baz => $baz ); # ok if a parent class defines boffo as a constructor param my $object = __PACKAGE__->new( foo => $foo, boffo => $boffo, );
%instance_vars may contain hashrefs and array-refs, as Clone's clone() method is used to produce a deep copy.
clone()
init_instance_vars() must be called from within a BEGIN block and before any use directives load a child class -- if children are born before their parents, inheritance gets screwed up.
use
A generic constructor with basic argument checking. new() expects hash-style labeled parameters; the label names must be present in the %instance_vars hash, or it will croak().
After verifying the labeled parameters, new() creates a deep clone of %instance_vars, and merges in the labeled arguments. It then calls $self->init_instance() before returning the blessed reference.
$self->init_instance();
Perform customized initialization routine. By default, this is a no-op.
BEGIN { __PACKAGE__->init_instance_vars( a_safe_variable_name_that_wont_clash => 1, freep_warble => undef, ); }
Package method only. Creates a package global %instance_vars hash in the passed in package which consists of the passed in arguments plus all the key-value pairs in the parent class's %instance_vars hash.
# create get_foo(), set_foo(), get_bar(), set_bar() in __PACKAGE__ BEGIN { __PACKAGE__->ready_get_set(qw( foo bar )) };
Mass manufacture getters and setters. The setters do not return a meaningful value.
sub an_abstract_method { shift->abstract_death } sub an_unimplemented_method { shift->unimplemented_death } sub maybe_someday { shift->todo_death }
These are just different ways to die(), and are of little interest until your particular application comes face to face with one of them.
abstract_death indicates that a method must be defined in a subclass.
unimplemented_death indicates a feature/function that will probably not be implemented. Typically, this would appear for a sub that a developer intimately familiar with Lucene would expect to find.
todo_death indicates a feature that might get implemented someday.
Copyright 2005-2006 Marvin Humphrey
See KinoSearch version 0.10.
To install KinoSearch, copy and paste the appropriate command in to your terminal.
cpanm
cpanm KinoSearch
CPAN shell
perl -MCPAN -e shell install KinoSearch
For more information on module installation, please visit the detailed CPAN module installation guide.