private static Expression <UntypedMapperFunc> Wrap(MapRequest mapRequest, LambdaExpression typedExpression)
{
var sourceParameter = Expression.Parameter(typeof(object), "source");
var destinationParameter = Expression.Parameter(typeof(object), "destination");
var contextParameter = Expression.Parameter(typeof(ResolutionContext), "context");
var requestedSourceType = mapRequest.RequestedTypes.SourceType;
var requestedDestinationType = mapRequest.RequestedTypes.DestinationType;
var destination = requestedDestinationType.IsValueType() ? Expression.Coalesce(destinationParameter, Expression.New(requestedDestinationType)) : (Expression)destinationParameter;
// Invoking a delegate here
return(Expression.Lambda <UntypedMapperFunc>(
ExpressionExtensions.ToType(
Expression.Invoke(typedExpression, ExpressionExtensions.ToType(sourceParameter, requestedSourceType), ExpressionExtensions.ToType(destination, requestedDestinationType), contextParameter)
, typeof(object)),
sourceParameter, destinationParameter, contextParameter));
}
private static LambdaExpression GenerateObjectMapperExpression(MapRequest mapRequest, IObjectMapper mapperToUse, MapperConfiguration mapperConfiguration)
{
var destinationType = mapRequest.RequestedTypes.DestinationType;
var source = Expression.Parameter(mapRequest.RequestedTypes.SourceType, "source");
var destination = Expression.Parameter(destinationType, "mapperDestination");
var context = Expression.Parameter(typeof(ResolutionContext), "context");
LambdaExpression fullExpression;
if (mapperToUse == null)
{
var message = Expression.Constant("Missing type map configuration or unsupported mapping.");
fullExpression = Expression.Lambda(Expression.Block(Expression.Throw(Expression.New(ExceptionConstructor, message, Expression.Constant(null, typeof(Exception)), Expression.Constant(mapRequest.RequestedTypes))), Expression.Default(destinationType)), source, destination, context);
}
else
{
var map = mapperToUse.MapExpression(mapperConfiguration.TypeMapRegistry, mapperConfiguration, null, ExpressionExtensions.ToType(source, mapRequest.RuntimeTypes.SourceType), destination, context);
var mapToDestination = Expression.Lambda(ExpressionExtensions.ToType(map, destinationType), source, destination, context);
fullExpression = TryCatch(mapToDestination, source, destination, context, mapRequest.RequestedTypes);
}
return(fullExpression);
}
private static LambdaExpression GenerateTypeMapExpression(MapRequest mapRequest, TypeMap typeMap)
{
var mapExpression = typeMap.MapExpression;
var typeMapSourceParameter = mapExpression.Parameters[0];
var typeMapDestinationParameter = mapExpression.Parameters[1];
var requestedSourceType = mapRequest.RequestedTypes.SourceType;
var requestedDestinationType = mapRequest.RequestedTypes.DestinationType;
if (typeMapSourceParameter.Type != requestedSourceType || typeMapDestinationParameter.Type != requestedDestinationType)
{
var requestedSourceParameter = Expression.Parameter(requestedSourceType, "source");
var requestedDestinationParameter = Expression.Parameter(requestedDestinationType, "typeMapDestination");
var contextParameter = Expression.Parameter(typeof(ResolutionContext), "context");
mapExpression = Expression.Lambda(ExpressionExtensions.ToType(Expression.Invoke(typeMap.MapExpression,
ExpressionExtensions.ToType(requestedSourceParameter, typeMapSourceParameter.Type),
ExpressionExtensions.ToType(requestedDestinationParameter, typeMapDestinationParameter.Type),
contextParameter
), mapRequest.RuntimeTypes.DestinationType),
requestedSourceParameter, requestedDestinationParameter, contextParameter);
}
return(mapExpression);
}