public static Expression GetFallbackCollectionValue(this IMemberMapperData mapperData)
{
var targetMember = mapperData.TargetMember;
Expression emptyEnumerable;
if (mapperData.TargetMemberHasInitAccessibleValue())
{
var existingValue = mapperData.GetTargetMemberAccess();
if (mapperData.MapToNullCollections())
{
return(existingValue);
}
emptyEnumerable = targetMember.Type.GetEmptyInstanceCreation(targetMember.ElementType);
return(Expression.Coalesce(existingValue, emptyEnumerable));
}
if (mapperData.MapToNullCollections())
{
return(targetMember.Type.ToDefaultExpression());
}
emptyEnumerable = targetMember.Type.GetEmptyInstanceCreation(targetMember.ElementType);
return(emptyEnumerable.GetConversionTo(targetMember.Type));
}
private static Expression GetValue(IMemberMapperData mapperData)
{
if (mapperData.TargetMember.IsReadable)
{
var existingValue = mapperData.GetTargetMemberAccess();
if (!mapperData.TargetMember.IsEnumerable)
{
return(existingValue);
}
var emptyEnumerable = mapperData.TargetMember.GetEmptyInstanceCreation();
return(Expression.Coalesce(existingValue, emptyEnumerable));
}
if (mapperData.TargetMember.IsEnumerable)
{
var emptyEnumerable = mapperData.TargetMember.GetEmptyInstanceCreation();
return(emptyEnumerable.GetConversionTo(mapperData.TargetMember.Type));
}
return(Expression.Default(mapperData.TargetMember.Type));
}
public PreserveExistingValueDataSource(IMemberMapperData mapperData)
: this(
mapperData.SourceMember,
mapperData.TargetMember.IsReadable
? mapperData.GetTargetMemberAccess()
: Constants.EmptyExpression)
{
}
private static Expression GetConversionOrCreationExpression(
this IMemberMapperData mapperData,
Expression value,
Type targetType,
IList <ConfiguredObjectFactory> valueFactories)
{
var simpleMemberMapperData = SimpleMemberMapperData.Create(value, mapperData);
var checkNestedAccesses =
simpleMemberMapperData.TargetMemberIsEnumerableElement() &&
value.Type.CanBeNull();
var replacements = FixedSizeExpressionReplacementDictionary
.WithEquivalentKeys(3)
.Add(simpleMemberMapperData.SourceObject, value)
.Add(simpleMemberMapperData.TargetObject, mapperData.GetTargetMemberAccess())
.Add(simpleMemberMapperData.ElementIndex, simpleMemberMapperData.ElementIndexValue);
var conversions = valueFactories.ProjectToArray(vf =>
{
var factoryExpression = vf.Create(simpleMemberMapperData);
var condition = vf.GetConditionOrNull(simpleMemberMapperData);
if (checkNestedAccesses)
{
var nestedAccessChecks = NestedAccessChecksFactory
.GetNestedAccessChecksFor(factoryExpression);
if (nestedAccessChecks != null)
{
condition = condition != null
? Expression.AndAlso(nestedAccessChecks, condition)
: nestedAccessChecks;
}
}
return(new SimpleTypeValueFactory
{
Factory = factoryExpression.Replace(replacements).GetConversionTo(targetType),
Condition = condition?.Replace(replacements)
});
});
if (conversions.Last().Condition != null)
{
conversions = conversions.Append(new SimpleTypeValueFactory
{
Factory = mapperData.GetValueConversion(value, targetType) ??
simpleMemberMapperData.GetTargetMemberDefault()
});
}
else if (conversions.Length == 1)
{
return(conversions[0].Factory);
}
return(GetConversionExpression(conversions));
}
private static Expression GetValue(IMemberMapperData mapperData)
{
if (mapperData.TargetMember.IsEnumerable)
{
return(FallbackToCollection(mapperData)
? mapperData.GetFallbackCollectionValue()
: mapperData.GetTargetMemberDefault());
}
if (mapperData.TargetMember.IsReadable && !mapperData.UseMemberInitialisations())
{
return(mapperData.GetTargetMemberAccess());
}
return(mapperData.GetTargetMemberDefault());
}
private static bool TryAdjustToSingleUseableDataSource(
ref IList <IDataSource> dataSources,
IMemberMapperData mapperData)
{
var finalDataSource = dataSources.Last();
if (!finalDataSource.IsFallback)
{
return(false);
}
var finalValue = finalDataSource.Value;
if (finalValue.NodeType == ExpressionType.Coalesce)
{
// Coalesce between the existing target member value and the fallback:
dataSources[dataSources.Count - 1] = new AdHocDataSource(
finalDataSource.SourceMember,
((BinaryExpression)finalValue).Right,
finalDataSource.Condition,
finalDataSource.Variables);
return(false);
}
var targetMemberAccess = mapperData.GetTargetMemberAccess();
if (!ExpressionEvaluation.AreEqual(finalValue, targetMemberAccess))
{
return(false);
}
if (dataSources.Count == 2)
{
return(true);
}
var dataSourcesWithoutFallback = new IDataSource[dataSources.Count - 1];
dataSourcesWithoutFallback.CopyFrom(dataSources);
dataSources = dataSourcesWithoutFallback;
return(false);
}