In the chatterbox today, I asked for help about a "factory" class.

"Factory" in quotes, as the chatterbox denizens quickly set me straight and let me know I didn't have the concept of a factory object right. Thanks all for your help.

I'm still curious about the idea, and wanted to ask the OO design gurus here in SOPW.

Here's my problem/idea:

I was seeking an object that would construct itself as the right type, depending on constructor parameters.

A factory class produces widget objects; it doesn't become a widget. In contrast, I was thinking about something like a seed: a seed doesn't produce plants, it turns itself into a plant.

Here's some pseudo-code: 


# untested code
#
# factory approach
my $factory = AnimalFoodFactory->new; 
my $food_object = 
AnimalFoodFactory->prepare_correct_chow(
    animal=> 'lion');
# now ref $food_object eq 'LionFood'

# "seed" (?) approach
my $food_object = AnimalFoodPreparer->new(animal=> 'lion');
# now ref $food_object eq 'LionFood'

[download]
My question: does this approach (a constructor that returns something of the right type depending on its parameters) have a name?

And does the approach make sense, or is Bad Practice?

Curious --

water

In reply to OO: Factory vs. "Seed" (?) pattern by water

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