Beefy Boxes and Bandwidth Generously Provided by pair Networks
go ahead... be a heretic

(jeffa) Re: Runtime instantiation decisions

by jeffa (Bishop)
on Mar 30, 2002 at 17:01 UTC ( #155442=note: print w/replies, xml ) Need Help??

in reply to Runtime instantiation decisions

Ahhh, the Factory Pattern!

All you need to do is make Astro::Observation the factory. It will return a class depending on what argument it receives. Here is a simple way to implement Astro::Observation:

package Astro::Observation; use Astro::Observation::Simple; use Astro::Observation::Complex; sub new { my $self = shift; my $class = shift; return Astro::Observation::Simple->new(@_) if 'simple' eq $class; return Astro::Observation::Complex->new(@_) if 'complex' eq $class; return undef; }
Which can be called like so:
my $obs = Astro::Observation->new("simple",'foo'); my $obc = Astro::Observation->new("complex",'bar');
But this way gets tiresome after you add more classes that the factory can deliver. I am quite sure that this can be avoided by using eval somehow.

UPDATE: once again - just do what the wise and resourceful Kanji said.

UPDATE x 2: that's what i was trying to do! :D
Here is a tar ball should anyone want to try this out.


(the triplet paradiddle with high-hat)

Log In?

What's my password?
Create A New User
Node Status?
node history
Node Type: note [id://155442]
and God said, "Let Newton be!"...

How do I use this? | Other CB clients
Other Users?
Others making s'mores by the fire in the courtyard of the Monastery: (1)
As of 2017-03-26 11:18 GMT
Find Nodes?
    Voting Booth?
    Should Pluto Get Its Planethood Back?

    Results (315 votes). Check out past polls.