private static ImportDefinition WrapImportDefinition(MefV1.Primitives.ImportDefinition definition)
{
Requires.NotNull(definition, nameof(definition));
var contractImportDefinition = definition as MefV1.Primitives.ContractBasedImportDefinition;
var constraints = ImmutableHashSet <IImportSatisfiabilityConstraint> .Empty
.Add(new ImportConstraint(definition));
if (contractImportDefinition != null)
{
constraints = constraints.Union(PartCreationPolicyConstraint.GetRequiredCreationPolicyConstraints(WrapCreationPolicy(contractImportDefinition.RequiredCreationPolicy)));
}
// Do NOT propagate the cardinality otherwise the export provider will throw
// if the cardinality is not met. But it's not our job to throw, since the caller
// is going to aggregate our response with other export providers and finally
// be responsible for throwing if the ultimate receiver of the result doesn't
// get what they expect.
// We use ZeroOrMore to indicate we'll accept any response.
var cardinality = ImportCardinality.ZeroOrMore;
var metadata = (IReadOnlyDictionary <string, object>)definition.Metadata;
MefV1.Primitives.ImportDefinition productImportDefinitionV1 = GetExportFactoryProductImportDefinitionIfApplicable(definition);
if (productImportDefinitionV1 != null)
{
var productImportDefinitionV3 = WrapImportDefinition(productImportDefinitionV1);
metadata = metadata.ToImmutableDictionary()
.Add(CompositionConstants.ExportFactoryProductImportDefinition, productImportDefinitionV3)
.Add(CompositionConstants.ExportFactoryTypeMetadataName, ExportFactoryV1Type);
}
return(new ImportDefinition(definition.ContractName, cardinality, metadata, constraints));
}
private bool TryCreateImportDefinition(Type importingType, ICustomAttributeProvider member, [NotNullWhen(true)] out ImportDefinition?importDefinition)
{
Requires.NotNull(importingType, nameof(importingType));
Requires.NotNull(member, nameof(member));
ImportAttribute importAttribute = member.GetFirstAttribute <ImportAttribute>();
ImportManyAttribute importManyAttribute = member.GetFirstAttribute <ImportManyAttribute>();
// Importing constructors get implied attributes on their parameters.
if (importAttribute == null && importManyAttribute == null && member is ParameterInfo)
{
importAttribute = new ImportAttribute();
}
if (importAttribute != null)
{
this.ThrowOnInvalidImportingMemberOrParameter(member, isImportMany: false);
if (importAttribute.Source != ImportSource.Any)
{
throw new NotSupportedException(Strings.CustomImportSourceNotSupported);
}
var requiredCreationPolicy = importingType.IsExportFactoryTypeV1()
? CreationPolicy.NonShared
: (CreationPolicy)importAttribute.RequiredCreationPolicy;
Type contractType = importAttribute.ContractType ?? GetTypeIdentityFromImportingType(importingType, importMany: false);
var constraints = PartCreationPolicyConstraint.GetRequiredCreationPolicyConstraints(requiredCreationPolicy)
.Union(this.GetMetadataViewConstraints(importingType, importMany: false))
.Union(GetExportTypeIdentityConstraints(contractType));
importDefinition = new ImportDefinition(
string.IsNullOrEmpty(importAttribute.ContractName) ? GetContractName(contractType) : importAttribute.ContractName,
importAttribute.AllowDefault ? ImportCardinality.OneOrZero : ImportCardinality.ExactlyOne,
GetImportMetadataForGenericTypeImport(contractType),
constraints);
return(true);
}
else if (importManyAttribute != null)
{
this.ThrowOnInvalidImportingMemberOrParameter(member, isImportMany: true);
if (importManyAttribute.Source != ImportSource.Any)
{
throw new NotSupportedException(Strings.CustomImportSourceNotSupported);
}
var requiredCreationPolicy = GetElementTypeFromMany(importingType).IsExportFactoryTypeV1()
? CreationPolicy.NonShared
: (CreationPolicy)importManyAttribute.RequiredCreationPolicy;
Type contractType = importManyAttribute.ContractType ?? GetTypeIdentityFromImportingType(importingType, importMany: true);
var constraints = PartCreationPolicyConstraint.GetRequiredCreationPolicyConstraints(requiredCreationPolicy)
.Union(this.GetMetadataViewConstraints(importingType, importMany: true))
.Union(GetExportTypeIdentityConstraints(contractType));
importDefinition = new ImportDefinition(
string.IsNullOrEmpty(importManyAttribute.ContractName) ? GetContractName(contractType) : importManyAttribute.ContractName,
ImportCardinality.ZeroOrMore,
GetImportMetadataForGenericTypeImport(contractType),
constraints);
return(true);
}
else
{
importDefinition = null;
return(false);
}
}