protected virtual Expression CreateInstantiationExpression(Expression source, Expression?destination, CompileArgument arg)
{
//new TDestination()
//if there is constructUsing, use constructUsing
var constructUsing = arg.GetConstructUsing();
if (constructUsing != null)
{
var args = destination == null ? new[] { source } : new[] { source, destination };
return(constructUsing.Apply(arg.MapType, args)
.TrimConversion(true)
.To(arg.DestinationType));
}
//if there is default constructor, use default constructor
else if (arg.DestinationType.HasDefaultConstructor())
{
return(Expression.New(arg.DestinationType));
}
//if mapToTarget or include derived types, allow mapping & throw exception on runtime
//instantiation is not needed
else if (destination != null || arg.Settings.Includes.Count > 0)
{
return(Expression.Throw(
Expression.New(
// ReSharper disable once AssignNullToNotNullAttribute
typeof(InvalidOperationException).GetConstructor(new[] { typeof(string) }),
Expression.Constant("Cannot instantiate type: " + arg.DestinationType.Name)),
arg.DestinationType));
}
//if mapping to interface, create dynamic type implementing it
else if (arg.DestinationType.GetTypeInfo().IsInterface)
{
return(Expression.New(DynamicTypeGenerator.GetTypeForInterface(arg.DestinationType)));
}
//otherwise throw
else
{
throw new InvalidOperationException($"No default constructor for type '{arg.DestinationType.Name}', please use 'ConstructUsing' or 'MapWith'");
}
}
protected override Expression CreateInstantiationExpression(Expression source, Expression?destination, CompileArgument arg)
{
//new TDestination(src.Prop1, src.Prop2)
if (arg.GetConstructUsing() != null)
{
return(base.CreateInstantiationExpression(source, destination, arg));
}
var destType = arg.DestinationType.GetTypeInfo().IsInterface
? DynamicTypeGenerator.GetTypeForInterface(arg.DestinationType)
: arg.DestinationType;
var ctor = destType.GetConstructors()[0];
var classModel = GetConstructorModel(ctor, false);
var classConverter = CreateClassConverter(source, classModel, arg);
return(CreateInstantiationExpression(source, classConverter, arg));
}
protected override Expression CreateInstantiationExpression(Expression source, Expression?destination, CompileArgument arg)
{
//new TDestination(src.Prop1, src.Prop2)
if (arg.GetConstructUsing() != null || arg.Settings.MapToConstructor == null)
{
return(base.CreateInstantiationExpression(source, destination, arg));
}
ClassMapping?classConverter;
var ctor = arg.Settings.MapToConstructor as ConstructorInfo;
if (ctor == null)
{
var destType = arg.DestinationType.GetTypeInfo().IsInterface
? DynamicTypeGenerator.GetTypeForInterface(arg.DestinationType, arg.Settings.Includes.Count > 0)
: arg.DestinationType;
if (destType == null)
{
return(base.CreateInstantiationExpression(source, destination, arg));
}
classConverter = destType.GetConstructors()
.OrderByDescending(it => it.GetParameters().Length)
.Select(it => GetConstructorModel(it, true))
.Select(it => CreateClassConverter(source, it, arg))
.FirstOrDefault(it => it != null);
}
else
{
var model = GetConstructorModel(ctor, false);
classConverter = CreateClassConverter(source, model, arg);
}
if (classConverter == null)
{
return(base.CreateInstantiationExpression(source, destination, arg));
}
return(CreateInstantiationExpression(source, classConverter, arg));
}