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Inheritance and NEXT

by pjf (Curate)
on Jun 25, 2002 at 00:20 UTC ( #176994=note: print w/replies, xml ) Need Help??

in reply to inheritance: constructors

Splitting construction from initialisation is a very common, clean, and recommended way of proceeding. It's already been covered, so I won't repeat it here. It's a good idea to do this even if you're not doing inheritance at the point -- things often change, and one of the advantages of OOP is that objects are supposed to be inheritable.

For a clean and easy way to call parent initialisers "when appropriate", you might consider the use of NEXT. NEXT will call your parent's constructor if it exists and if it's appropriate. It will handle multiple inheritance without difficulty. It's also going to be a standard module in Perl 5.8.0.

use NEXT; # ... sub _init { my $self = shift; $self->NEXT::UNSEEN::_init(@_); # My init goes here... }
You can find a whole chapter on NEXT and why it's useful in the Object Oriented Perl training notes from Perl Training Australia. TheDamian has also written an article on use.perl which can be found here.

Paul Fenwick
Perl Training Australia

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[atcroft]: PriNet: Those code bits worked for me, with test hashes, but I didn't test it with more than a few simple test cases. *shrug* Had hoped it would help, at least.
[PriNet]: i think i found the problem, the "source" array that sets the individual key values isn't being cleared, it's keeping the previous values...
[atcroft]: PriNet: You might consider posting a small, self-contained snippet of that segment of your code, and see if someone else has a better idea.....
[atcroft]: PriNet: Ahhh... interesting.

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