/// <summary>
/// Register a MEF part definition.
/// </summary>
/// <param name="builder">The container builder.</param>
/// <param name="partDefinition">The part definition to register.</param>
/// <param name="exposedServicesMapper">A mapping function to transform ExportDefinitions into Services.</param>
public static void RegisterComposablePartDefinition(this ContainerBuilder builder, ComposablePartDefinition partDefinition, Func <ExportDefinition, IEnumerable <Service> > exposedServicesMapper)
{
if (builder == null)
{
throw new ArgumentNullException("builder");
}
if (partDefinition == null)
{
throw new ArgumentNullException("partDefinition");
}
if (exposedServicesMapper == null)
{
throw new ArgumentNullException("exposedServicesMapper");
}
var partId = new UniqueService();
var partRegistration = builder.Register(c => partDefinition.CreatePart())
.OnActivating(e => SetPrerequisiteImports(e.Context, e.Instance))
.OnActivated(e => SetNonPrerequisiteImports(e.Context, e.Instance))
.As(partId);
if (IsSharedInstance(partDefinition))
{
partRegistration.SingleInstance();
}
foreach (var iterExportDef in partDefinition.ExportDefinitions)
{
var exportDef = iterExportDef;
var contractService = new ContractBasedService(exportDef.ContractName, GetTypeIdentity(exportDef));
var exportId = new UniqueService();
builder.Register(c =>
{
var p = ((ComposablePart)c.ResolveService(partId));
return(new Export(exportDef, () => p.GetExportedValue(exportDef)));
})
.As(exportId, contractService)
.ExternallyOwned()
.WithMetadata(exportDef.Metadata);
var additionalServices = exposedServicesMapper(exportDef).ToArray();
if (additionalServices.Length > 0)
{
builder.Register(c => ((Export)c.ResolveService(exportId)).Value)
.As(additionalServices)
.ExternallyOwned()
.WithMetadata(exportDef.Metadata);
}
}
}
private static IEnumerable <Export> ResolveExports(this IComponentContext context, ContractBasedImportDefinition cbid)
{
var contractService = new ContractBasedService(cbid.ContractName, cbid.RequiredTypeIdentity);
var componentsForContract = context.ComponentsForContract(cbid, contractService);
var exportsForContract = componentsForContract
.Select(cpt => context.ResolveComponent(new ResolveRequest(contractService, cpt, Enumerable.Empty <Parameter>())))
.Cast <Export>()
.ToList();
return(exportsForContract);
}
/// <summary>
/// Locate all of the MEF exports registered as supplying contract type T.
/// </summary>
/// <param name="contractName">The contract name.</param>
/// <param name="context">The context to resolve exports from.</param>
/// <returns>A list of exports.</returns>
public static IEnumerable <Export> ResolveExports <T>(this IComponentContext context, string contractName)
{
if (context == null)
{
throw new ArgumentNullException(nameof(context));
}
var service = new ContractBasedService(contractName, AttributedModelServices.GetTypeIdentity(typeof(T)));
return(context.ComponentRegistry
.RegistrationsFor(service)
.Select(cpt => context.ResolveComponent(new ResolveRequest(service, cpt, Enumerable.Empty <Parameter>())))
.Cast <Export>());
}
private static void ProcessExportDefinition(ContainerBuilder builder, Func <ExportDefinition, IEnumerable <Service> > exposedServicesMapper, UniqueService partId, ExportDefinition iterExportDef)
{
var exportDef = iterExportDef;
var contractService = new ContractBasedService(exportDef.ContractName, GetTypeIdentity(exportDef));
var exportIsShared = IsSharedInstance(exportDef);
var exportId = new UniqueService();
var exportReg = builder.Register(c =>
{
var p = (ComposablePart)c.ResolveService(partId);
return(new Export(exportDef, () => p.GetExportedValue(exportDef)));
})
.As(exportId, contractService)
.ExternallyOwned()
.WithMetadata(exportDef.Metadata);
// Issue #348: When a constructor takes in a duplicate dependency like:
// public ImportsDuplicateMefClass(ImportsMefDependency first, ImportsMefDependency second)
// and each of those dependencies also take in the same thing:
// public ImportsMefDependency(IDependency dependency)
// Then when the export/import process gets run, if the export doesn't have
// the same lifetime scope sharing (per-instance vs. singleton) you
// have trouble because the OnActivating from above in the original part
// registration doesn't run, the chained-in prerequisite imports never get
// populated, and everything fails. Setting the export registrations to be
// the same lifetime scope as the part they correspond to fixes the issue.
if (exportIsShared)
{
exportReg.SingleInstance();
}
var additionalServices = exposedServicesMapper(exportDef).ToArray();
if (additionalServices.Length > 0)
{
var addlReg = builder.Register(c => ((Export)c.ResolveService(exportId)).Value)
.As(additionalServices)
.ExternallyOwned()
.WithMetadata(exportDef.Metadata);
if (exportIsShared)
{
addlReg.SingleInstance();
}
}
}
private static void AttachExport(IComponentRegistryBuilder registry, IComponentRegistration registration, ExportConfigurationBuilder exportConfiguration)
{
var contractService = new ContractBasedService(exportConfiguration.ContractName, exportConfiguration.ExportTypeIdentity);
var rb = RegistrationBuilder.ForDelegate((c, p) =>
{
var ctx = c.Resolve <IComponentContext>();
return(new Export(
new ExportDefinition(exportConfiguration.ContractName, exportConfiguration.Metadata),
() => ctx.ResolveComponent(new ResolveRequest(contractService, registration, Array.Empty <Parameter>()))));
})
.As(contractService)
.ExternallyOwned()
.WithMetadata((IEnumerable <KeyValuePair <string, object> >)exportConfiguration.Metadata);
registry.Register(rb.CreateRegistration());
}
static void AttachExport(IComponentRegistry registry, IComponentRegistration registration, ExportConfigurationBuilder exportConfiguration)
{
var contractService = new ContractBasedService(exportConfiguration.ContractName, exportConfiguration.ExportTypeIdentity);
var rb = RegistrationBuilder.ForDelegate((c, p) =>
{
var ctx = c.Resolve <IComponentContext>();
return(new Export(
new ExportDefinition(exportConfiguration.ContractName, exportConfiguration.Metadata),
() => ctx.ResolveComponent(registration, new Parameter[0])));
})
.As(contractService)
.ExternallyOwned()
.WithMetadata(exportConfiguration.Metadata);
registry.Register(rb.CreateRegistration());
}
static IEnumerable <IComponentRegistration> ComponentsForContract(this IComponentContext context, ContractBasedImportDefinition cbid)
{
var contractService = new ContractBasedService(cbid.ContractName, cbid.RequiredTypeIdentity);
var componentsForContract = context
.ComponentRegistry
.RegistrationsFor(contractService)
.Where(cpt =>
!cbid.RequiredMetadata
.Except(cpt.Metadata.Select(m => new KeyValuePair <string, Type>(m.Key, m.Value.GetType())))
.Any())
.ToList();
if (cbid.Cardinality == ImportCardinality.ExactlyOne && componentsForContract.Count == 0)
{
throw new ComponentNotRegisteredException(contractService);
}
return(componentsForContract);
}
