private bool CanUseDirectAssignment(TypePair pair, PropertyOrFieldInfo destinationMember, PropertyOrFieldInfo sourceMember, Type nullableType, ProposedHierarchicalMapping hierarchicalMapping)
{
Type sourceMemberType = null;
if (sourceMember == null)
{
if (hierarchicalMapping == null)
{
return(false);
}
}
else
{
sourceMemberType = sourceMember.PropertyOrFieldType;
}
if (hierarchicalMapping != null)
{
sourceMemberType = hierarchicalMapping.ReturnType;
}
if (!destinationMember.PropertyOrFieldType.IsAssignableFrom(sourceMemberType))
{
if (sourceMemberType.IsNullableValueType() && destinationMember.PropertyOrFieldType.IsAssignableFrom(nullableType))
{
return(true);
}
else if (ConversionTypeHelper.AreConvertible(sourceMemberType, destinationMember.PropertyOrFieldType))
{
return(true);
}
else
{
return(false);
}
}
if (pair.SourceType == pair.DestinationType && this.options.Conventions.MakeCloneIfDestinationIsTheSameAsSource)
{
if (sourceMemberType.IsValueType || sourceMemberType == typeof(string))
{
return(true);
}
else
{
return(false);
}
}
// Can't assign enumerable memebers to eachother, we leave that decision to the code
// generator which can determine if we need to preserve the contents of the enumerable.
if (CollectionTypeHelper.IsEnumerable(destinationMember.PropertyOrFieldType) &&
CollectionTypeHelper.IsEnumerable(sourceMemberType) &&
this.options.Conventions.PreserveDestinationListContents) // but only if the option is turned on at all
{
return(false);
}
return(true);
}
/// <summary>
/// Returns a type mapping of the TypePair you pass in.
/// </summary>
/// <returns></returns>
private ProposedTypeMapping GetTypeMapping(int currentDepth, TypePair pair, MemberOptions options = null, CustomMapping customMapping = null)
{
if (!typeStack.Contains(pair))
{
typeStack.Push(pair);
}
else if (this.options.Safety.IfRecursiveRelationshipIsDetected == RecursivePropertyOptions.ThrowIfRecursionIsDetected)
{
// Oh noes, recursion!
throw new RecursiveRelationshipException(pair);
}
// if it's a recursive relationship, by default we return null which is handled after the method returns
else
{
return(null);
}
var typeMapping = new ProposedTypeMapping();
typeMapping.SourceMember = null;
typeMapping.DestinationMember = null;
Type destinationType, sourceType;
// If it's an enumerable type (List<>, IEnumerable<>, etc) then we're currently interested
// in the type 'inside' the enumerable.
if (CollectionTypeHelper.IsEnumerable(pair.DestinationType))
{
destinationType = CollectionTypeHelper.GetTypeInsideEnumerable(pair.DestinationType);
}
else
{
destinationType = pair.DestinationType;
}
// Same here.
if (CollectionTypeHelper.IsEnumerable(pair.SourceType))
{
sourceType = CollectionTypeHelper.GetTypeInsideEnumerable(pair.SourceType);
}
else
{
sourceType = pair.SourceType;
}
// The memberprovider is responsible for linking a destination member with a source member
var memberProvider = this.strategy.MemberProviderFactory.GetMemberProvider(sourceType, destinationType, mapper);
// Loop through all members it could find
foreach (var mapping in GetTypeMembers(memberProvider, options, currentDepth))
{
var destinationMember = mapping.Destination;
var sourceMember = mapping.Source;
// Does the memberprovider see any reason to ignore this member?
if (memberProvider.IsMemberIgnored(sourceType, destinationMember))
{
continue;
}
Expression customExpression = null;
// Try to extract an expression that was supplied for this destination member
if (customMapping != null)
{
customExpression = customMapping.GetExpressionForMember(destinationMember);
if (mapping.ConversionFunction == null)
{
var conversionFunction = customMapping.GetConversionFunction(sourceMember, destinationMember);
mapping.ConversionFunction = conversionFunction;
}
}
// Did the user supply a function to transform the source member's value?
if (mapping.ConversionFunction != null)
{
// If no custom mapping yet, then we need to create one
// as it's where we'll be storing the conversion function
if (customMapping == null)
{
customMapping = new CustomMapping
{
DestinationType = destinationType
};
customMappingCache.AddOrUpdate(pair, customMapping, (k, v) => customMapping);
typeMapping.CustomMapping = customMapping;
}
// Let the custom mapping be the owner of the conversion function
customMapping.AddConversionFunction(sourceMember, destinationMember, mapping.ConversionFunction);
}
else if (customMapping != null)
{
}
ProposedHierarchicalMapping hierarchicalMapping = null;
// No source member or can't write to the destination?
if (HasNoSourceMember(customExpression, sourceMember) || !destinationMember.CanWrite)
{
if (this.options.Conventions.AutomaticallyFlattenHierarchies)
{
// Propose a mapping that flattens a hierarchy if possible.
// For example, map type.CompanyName to otherType.Company.Name
hierarchicalMapping = memberProvider.ProposeHierarchicalMapping(destinationMember);
}
// No way to map this thing? Add it to incompatible members if the option has been turned on.
// Will cause an (intended) exception later on, allowing you to verify your mappings
// for correctness and completeness.
if (hierarchicalMapping == null && this.options.Strictness.ThrowWithoutCorrespondingSourceMember)
{
typeMapping.IncompatibleMappings.Add(destinationMember);
}
}
// Nullable value types screw up everything!
var nullableType = NullableTypeHelper.TryGetNullableType(sourceMember);
// Can we do a simple right to left assignment between the members?
// So, are they basically the same type or do we need to do further mapping?
var canUseSimpleTypeMapping = CanUseDirectAssignment(pair, destinationMember, sourceMember, nullableType, hierarchicalMapping);
if (canUseSimpleTypeMapping)
{
// If simple mapping is possible create a mapping between the members
typeMapping.ProposedMappings.Add
(
new ProposedMemberMapping
{
SourceMember = sourceMember,
DestinationMember = destinationMember,
HierarchicalMapping = hierarchicalMapping
}
);
}
// No simple assignment, but a custom expression is supplied
// and that's just as good as having a direct assignment mapping
else if (customExpression != null || mapping.ConversionFunction != null)
{
typeMapping.ProposedMappings.Add
(
new ProposedMemberMapping
{
SourceMember = sourceMember,
DestinationMember = destinationMember,
HierarchicalMapping = hierarchicalMapping
}
);
}
// We have a source member but can't directly assign the source to the destination.
// Further mapping is needed.
else if (sourceMember != null)
{
// Is the member of an IEnumerable type?
if (AreMembersIEnumerable(destinationMember, sourceMember))
{
// Create a deeper mapping for IEnumerable members
GenerateEnumerableMapping(currentDepth, options, customMapping, typeMapping, destinationMember, sourceMember);
}
else
{
// Create a deeper mapping for a 'regular' type.
GenerateComplexTypeMapping(currentDepth, options, customMapping, typeMapping, destinationMember, sourceMember);
}
}
// All we have is a destination member and a custom expression
// that gives the destination member a value. Good enough!
else if (customExpression != null)
{
typeMapping.ProposedMappings.Add
(
new ProposedMemberMapping
{
SourceMember = null,
DestinationMember = destinationMember
}
);
}
}
// Don't cache the typemapping when this flag has been set.
// That happens when the maximum depth was reached during the mapping
// for this particular type and we didn't explore the full depth
// of the type. We don't wanna reuse this typemapping at a later time
// because the mapping might be for something completely different
// at a depth at which the full depth CAN be explored.
if (!typeMapping.DoNotCache)
{
mappingCache[pair] = typeMapping;
}
typeStack.Pop();
return(typeMapping);
}