[Openinteract-help] techniques to create inheritance between SPOPS objects

[Nick S. <ni...@te...>]

hi all!

i'm thinking of providing a "plug-in" mechanism so that programmers can
extend an existing SPOPS object with additional properties and even new
functionality (methods).

i use the setup found in the SPOPS/eg dir which is of course chris' idea:
- have one class per object
- the class has at least two methods which are
- _base_config(): returns the SPOPS config hash
- config_class(): calls SPOPS::Initialize->process() with the config hash
from _base_config()

my idea is to write a new sub-class of the respective object. the
constructor of the new object will call the "_base_config" method from its
parent and extend the returned array as necessary, eg with more "has_a"
fields.

there are a few problems with this technique:
if an object has "has_a" properties (which are again classes), the
config_class() methods of these classes have to be called *before* the
respective class calls SPOPS::Initialize->process(), because the "has_a"
classes must be "known" by the SPOPS subsystem (which means, they must
have been created by SPOPS before).

one solution is of course calling the config_class() method of all "has_a"
classes *in* the SPOPS::Initialize->process() call of the respective
class. this is the way chris goes in the example code.
this may result in multiple config_class() calls of a single class.

has anyone another solution for this?

what do you think about this "inheritance" technique?

is this text understandable at all?


cheers,



	nick



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nick sutterer	cb&h productions
ni...@te...
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