re-motion mixins basics -- instantiation with parameters
re-motion in general uses parameter lists for passing parameters for constructors to the object factory. The mechanism is explained in the PhoneBook tutorial for NewObject<T>
(section NewObject<T>
with parameters).
For every class for which you want to have instantiation with parameters, you must create a constructor. Let's say you want a DessertTopping
with flavors:
public enum Flavor { Mint, Banana, Strawberry, Licorice, Cinnamon }
What you need is a constructor for DessertTopping
that does the right thing:
public DessertTopping (Flavor flavor) { // we assume that 'DessertTopping' now has a // 'Flavor Flavor' property Flavor = flavor; }
You are basically set. Instantiation does ***NOT*** work like this:
ObjectFactory.Create<DessertTopping> (Flavor.Licorice)
It works like this:
ObjectFactory.Create<DessertTopping> (ParamList.Create (Flavor.Licorice));
ParamList.Create ()
returns a parameter list object and is a generic, strongly typed method (although it doesn't look like it). The object factory's Create<DessertTopping>
finds the matching constructor by reflection (if you have declared that constructor) and calls it automatically.
If the empty parameter list (ParamList.Empty
) is passed, then the default constructor is used.