Question

I used FxCop to analyze some code I had written. I had exposed a collection via a setter. I understand why this is not good. Changing the backing store when I don’t expect it is a very bad idea. Here is my problem though. I retrieve a list of business objects from a Data Access Object. I then need to add that collection to another business class and I was doing it with the setter method. The reason I did this was that it is going to be faster to make an assignment than to insert hundreds of thousands of objects one at a time to the collection again via another addElement method.

Is it okay to have a getter for a collection in some scenarios?
I though of rather having a constructor which takes a collection?
I thought maybe I could pass the object in to the Dao and let the Dao populate it directly?
Are there any other better ideas?

Answer 1

I would still make the property read only, and provide an alternative method that takes a collection and does the assignment — possibly the constructor. Sure, that’s a what a property setter is supposed to be for, but this makes it really clear to a class user that you don’t expect this property to moved out from under you, and assignment should only happen in exceptional circumstances.