/// <summary>
/// This methods splits the list of objects into their correct subtypes (based on the given key)
/// </summary>
/// <param name="currentKey">The key for the instances e.g. Dog.Cat of type Animal</param>
/// <param name="instances">The concrete instances for this property e.g 10 instance of AngoraCat and 10 instances of TigerCat</param>
/// <returns>a dictionary that maps each concrete type to the corresponding instances and the correct key - so in this case you would get {{AngoraCat, {Cat1, Cat3, Cat 5}}, {TigerCat, {Cat2, Cat4,...}}}</returns>
internal static Dictionary <Type, SubTypeInstanceHolder> SplitUpSubTypes(IKey currentKey, IList <object> instances)
{
//First we check if all instances are of the same concrete type as the property (e.g. only Animals)
if (instances.Where(instance => instance != null).All(instance => instance.GetType() == currentKey.Type))
{
//if this is the case we return a dictionary with just this type (for convenience)
return(new Dictionary <Type, SubTypeInstanceHolder> {
{ currentKey.Type, new SubTypeInstanceHolder(currentKey, instances) }
});
}
//otherwise we have to get all the concrete types
var typeToInstances = new Dictionary <Type, SubTypeInstanceHolder>();
foreach (var instance in instances.Where(instance => instance != null))
{
//we get the concrete type of the instance - e.g. AngoraCat
var concreteType = instance.GetType();
//now we check if this is the first instance
if (!typeToInstances.ContainsKey(concreteType))
{
//if it is the first property we add it, but we need to change the type of the key (as this might use other value providers)
typeToInstances.Add(
concreteType,
new SubTypeInstanceHolder(currentKey.ChangeMemberType(concreteType)));
}
//if it was not the first instance, we just add it to the old mapping (this is basically for performance reasons, see CompoundValueProvider for more info
typeToInstances[concreteType].Instances.Add(instance);
}
return(typeToInstances);
}