Can I find out if a class is an abstract class before trying to instantiate it?
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Can i somehow say:
if isAbstract(className)
% do something
else
% do something else
end
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per isakson
le 17 Juil 2012
Modifié(e) : per isakson
le 17 Juil 2012
A class is abstract if any of its properties or methods is abstract.
It's possible to write a function, is_abstract. Start:
mco = ?my_class
mco.PropertyList
mco.MethodList
any([mco.MethodList.Abstract])
.
or better
mcls = meta.class.fromName('ClassName')
3 commentaires
Daniel Shub
le 18 Juil 2012
@Walter, but that "hidden" abstract method would be abstract and eventually caught. The metaclass object has access to all methods and properties (even private ones), so I do not think it needs to be recursive.
Plus de réponses (4)
Image Analyst
le 17 Juil 2012
I don't think so. But you should know just by looking at the code, or just try it and see. Why would you ever not know what you're calling and have to use the test you you described? Worst case, you could wrap your method call in a try/catch to do what you want, but I would recommend knowing beforehand than doing that.
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Daniel Shub
le 18 Juil 2012
It might be quicker to try and create the object in a try-catch and deal with errors when they happen.
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