NAME¶
KiokuDB::Meta::Attribute::Lazy - Trait for lazy loaded attributes
SYNOPSIS¶
# in your class:
package Foo;
use KiokuDB::Class;
has bar => (
traits => [qw(KiokuDB::Lazy)],
isa => "Bar",
is => "ro",
);
# Later:
my $foo = $dir->lookup($id);
# bar is not yet loaded, it will be lazily fetched during this call:
$foo->bar;
DESCRIPTION¶
This Moose::Meta::Attribute trait provides lazy loading on a per field basis for
objects stored in KiokuDB.
Instead of using proxy objects with AUTOLOAD, overloading, or similar hacks, you
can declaratively specify which attributes you want to make lazy, and this
will be done cleanly through the MOP.
This is implemented by using a placeholder object, KiokuDB::Thunk which contains
references to the ID and the linker, and KiokuDB::Meta::Instance will know to
replace the placeholder with the actual loaded object when it is fetched from
the object by an accessor.