private IEnumerable <Expression> GetConfiguredToTargetDataSourceMappings(MappingCreationContext context)
{
if (!HasConfiguredToTargetDataSources(context.MapperData, out var configuredToTargetDataSources))
{
yield break;
}
for (var i = 0; i < configuredToTargetDataSources.Count;)
{
var configuredToTargetDataSource = configuredToTargetDataSources[i++];
var newSourceContext = context.WithDataSource(configuredToTargetDataSource);
AddPopulationsAndCallbacks(newSourceContext);
if (newSourceContext.MappingExpressions.None())
{
continue;
}
context.UpdateFrom(newSourceContext);
var mapping = newSourceContext.MappingExpressions.HasOne()
? newSourceContext.MappingExpressions.First()
: Expression.Block(newSourceContext.MappingExpressions);
mapping = MappingFactory.UseLocalToTargetDataSourceVariableIfAppropriate(
context.MapperData,
newSourceContext.MapperData,
configuredToTargetDataSource.Value,
mapping);
if (!configuredToTargetDataSource.IsConditional)
{
yield return(mapping);
continue;
}
if (context.MapperData.TargetMember.IsComplex || (i > 1))
{
yield return(Expression.IfThen(configuredToTargetDataSource.Condition, mapping));
continue;
}
var fallback = context.MapperData.LocalVariable.Type.GetEmptyInstanceCreation(
context.TargetMember.ElementType,
context.MapperData.EnumerablePopulationBuilder.TargetTypeHelper);
var assignFallback = context.MapperData.LocalVariable.AssignTo(fallback);
yield return(Expression.IfThenElse(configuredToTargetDataSource.Condition, mapping, assignFallback));
}
}
private Expression GetConfiguredToTargetDataSourceMappingOrNull(
MappingCreationContext context,
IConfiguredDataSource toTargetDataSource,
bool isFirstDataSource)
{
if (context.MapperData.Context.IsForToTargetMapping)
{
return(null);
}
var toTargetContext = context.WithToTargetDataSource(toTargetDataSource);
AddPopulationsAndCallbacks(toTargetContext);
if (toTargetContext.MappingExpressions.None())
{
return(null);
}
context.UpdateFrom(toTargetContext, toTargetDataSource);
var originalMapperData = context.MapperData;
var isSequential = toTargetDataSource.IsSequential;
if (!isSequential)
{
toTargetContext.MappingExpressions.Add(
context.MapperData.GetReturnExpression(GetExpressionToReturn(toTargetContext)));
}
var toTargetMapping = MappingFactory.UseLocalToTargetDataSourceVariableIfAppropriate(
originalMapperData,
toTargetContext.MapperData,
toTargetDataSource.Value,
toTargetContext.GetMappingExpression());
var hasCondition = isSequential
? toTargetDataSource.IsConditional
: toTargetDataSource.HasConfiguredCondition;
if (!hasCondition)
{
return(toTargetMapping);
}
Expression fallback;
if (!isFirstDataSource || originalMapperData.TargetMember.IsComplex)
{
if (isSequential || !originalMapperData.TargetMemberIsEnumerableElement())
{
return(Expression.IfThen(toTargetDataSource.Condition, toTargetMapping));
}
// Mapping a configured ToTargetInstead() data source to
// a complex type enumerable element member; reset the
// local instance variable to null to prevent reuse of a
// previous element's mapping result:
fallback = originalMapperData.GetTargetMemberDefault();
}
else
{
fallback = originalMapperData.LocalVariable.Type.GetEmptyInstanceCreation(
context.TargetMember.ElementType,
originalMapperData.EnumerablePopulationBuilder.TargetTypeHelper);
}
var assignFallback = originalMapperData.LocalVariable.AssignTo(fallback);
return(Expression.IfThenElse(toTargetDataSource.Condition, toTargetMapping, assignFallback));
}