internal AttemptTuple <MapperDefinition> TryGetMapper(Type source, Type target, bool createIfNonExistant)
{
Func <AttemptTuple <MapperDefinition> > findTypeMapper = () =>
{
//if we have a specified TypeMapper for <TSource,Target>
MapperDefinition mapper;
if (_mappers.TryGetValue(new TypeMapDefinition(source, target), out mapper))
{
return(new AttemptTuple <MapperDefinition>(true, mapper));
}
//now, check if we have the specified mapper using type inheritance
var found = _mappers.Where(x => x.Value.Metadata.PermitTypeInheritance && x.Value.Metadata.SourceType.IsAssignableFrom(source) &&
x.Value.Metadata.DestinationType.IsAssignableFrom(target)).ToArray();
if (found.Any())
{
return(new AttemptTuple <MapperDefinition>(true, found.Single().Value));
}
return(AttemptTuple <MapperDefinition> .False);
};
var result = findTypeMapper();
if (result.Success)
{
return(result);
}
//if we've got this far, then create a new default map and add it to our mappers
if (createIfNonExistant)
{
//need to lock as there could be many threads trying to do the same thing with the same types
using (new WriteLockDisposable(_locker))
{
//we'll now actually need to re-check if it exists
result = findTypeMapper();
if (result.Success)
{
return(result);
}
//if both Source and Target types are Enumerables return new EnumerableTypeMapper<TSource,TTarget>()
if (source.IsEnumerable() && target.IsEnumerable())
{
var mapper = (ITypeMapper)
Activator.CreateInstance(typeof(EnumerableTypeMapper <,>).MakeGenericType(source, target)
, this); //pass this factory into the constructor
//create the map and store it against our list
var meta = new TypeMapperMetadata(source, target, false);
var mapperDef = new MapperDefinition(mapper, meta);
return(new AttemptTuple <MapperDefinition>(true,
_mappers.GetOrAdd(new TypeMapDefinition(source, target), mapperDef)));
}
else
{
//if not enumerable, just create a normal map
var concreteTypeMapper = typeof(TypeMapper <,>).MakeGenericType(new[] { source, target });
var mapper = (ITypeMapper)Creator.Create(concreteTypeMapper, this);
var defaultMeta = new TypeMapperMetadata(source, target, false);
var defaultMapperDef = new MapperDefinition(mapper, defaultMeta);
return(new AttemptTuple <MapperDefinition>(true,
_mappers.GetOrAdd(new TypeMapDefinition(source, target), defaultMapperDef)));
}
}
}
return(AttemptTuple <MapperDefinition> .False);
}
/// <summary>
/// Maps the source object and source object type to the destinationSubclassType based on a mapper that supports inheritance
/// with a destination type specified as the destinationBaseclassType.
/// </summary>
/// <remarks>
/// An example of this is if a map was defined to go from an Examine SearchResult to a TypedEntity with the allow inheritance flag
/// set to true and then a mapping operation occured from a SearchResult to a User (a subclass of TypedEntity).
///
/// This method will first check to see if there is a mapping operation declared to go between the baseclass to the subclass, if so
/// it will perform the normal mapping from the source object to the destinationBaseclassType, and then map from the base class type
/// to the sub class type.
///
/// If this method doesn't find a map to go from the base class type to the sub class type, it will attempt to instantiate a new
/// instance of the subclass and then do a map to the new existing object using the mapper already defined.
/// </remarks>
/// <param name="source"></param>
/// <param name="sourceType"></param>
/// <param name="destinationBaseclassType"></param>
/// <param name="destinationSubclassType"></param>
/// <param name="mapperDefinition"></param>
/// <param name="scope"></param>
/// <returns></returns>
protected virtual object MapToSubclass(object source, Type sourceType, Type destinationBaseclassType, Type destinationSubclassType, MapperDefinition mapperDefinition, MappingExecutionScope scope)
{
if (TypeFinder.IsTypeAssignableFrom(destinationSubclassType, destinationBaseclassType))
{
//if its assignable, just map it
return(mapperDefinition.Mapper.Map(source, scope));
}
if (destinationSubclassType.IsSubclassOf(destinationBaseclassType))
{
//we need to see if there's a mapping registered to go from the base class to the sub class,
//if so, we'll do the normal mapping to the base class, and then map again to the sub class.
var subclassTypeMapDef = TryGetMapper(destinationBaseclassType, destinationSubclassType, false);
if (subclassTypeMapDef.Success)
{
//there's actually a map declared to go from the base class to subclass type, so well first
//map to the base class type from the source, then from the base class type to the sub class type.
var baseTypeMapped = mapperDefinition.Mapper.Map(source);
return(subclassTypeMapDef.Result.Mapper.Map(baseTypeMapped, scope));
}
//there's no map declared so we need to now try to create the 'subclass' type and then map to that existing object
try
{
var mapTo = Activator.CreateInstance(destinationSubclassType);
Map(source, mapTo, sourceType, destinationSubclassType);
return(mapTo);
}
catch (MissingMethodException ex)
{
throw new InvalidOperationException(
string.Format("Could not map from {0} to {1} because {1} does not have a parameterless constructor", sourceType.Name, destinationSubclassType.Name), ex);
}
}
throw new InvalidCastException("Cannot map from type " + sourceType + " to subclass type " + destinationSubclassType + " from the map specified for the baseclass type " + destinationBaseclassType);
}