/// <summary>
/// Returns all exports that match the conditions of the specified import.
/// </summary>
/// <param name="definition">The <see cref="ImportDefinition"/> that defines the conditions of the
/// <see cref="Export"/> to get.</param>
/// <returns></returns>
/// <result>
/// An <see cref="IEnumerable{T}"/> of <see cref="Export"/> objects that match
/// the conditions defined by <see cref="ImportDefinition"/>, if found; otherwise, an
/// empty <see cref="IEnumerable{T}"/>.
/// </result>
/// <remarks>
/// <note type="inheritinfo">
/// The implementers should not treat the cardinality-related mismatches as errors, and are not
/// expected to throw exceptions in those cases.
/// For instance, if the import requests exactly one export and the provider has no matching exports or more than one,
/// it should return an empty <see cref="IEnumerable{T}"/> of <see cref="Export"/>.
/// </note>
/// </remarks>
protected override IEnumerable <Export> GetExportsCore(ImportDefinition definition, AtomicComposition atomicComposition)
{
ThrowIfDisposed();
IEnumerable <Export> exports = null;
object source;
if (!definition.Metadata.TryGetValue(CompositionConstants.ImportSourceMetadataName, out source))
{
source = ImportSource.Any;
}
switch ((ImportSource)source)
{
case ImportSource.Any:
Assumes.NotNull(_rootProvider);
_rootProvider.TryGetExports(definition, atomicComposition, out exports);
break;
case ImportSource.Local:
Assumes.NotNull(_localExportProvider);
_localExportProvider.TryGetExports(definition.RemoveImportSource(), atomicComposition, out exports);
break;
case ImportSource.NonLocal:
if (_ancestorExportProvider != null)
{
_ancestorExportProvider.TryGetExports(definition.RemoveImportSource(), atomicComposition, out exports);
}
break;
}
return(exports);
}
/// <summary>
/// Returns all exports that match the conditions of the specified import.
/// </summary>
/// <param name="definition">The <see cref="ImportDefinition"/> that defines the conditions of the
/// <see cref="Export"/> to get.</param>
/// <param name="atomicComposition">The transactional container for the composition.</param>
/// <returns></returns>
/// <result>
/// An <see cref="IEnumerable{T}"/> of <see cref="Export"/> objects that match
/// the conditions defined by <see cref="ImportDefinition"/>, if found; otherwise, an
/// empty <see cref="IEnumerable{T}"/>.
/// </result>
/// <remarks>
/// <note type="inheritinfo">
/// The implementers should not treat the cardinality-related mismatches as errors, and are not
/// expected to throw exceptions in those cases.
/// For instance, if the import requests exactly one export and the provider has no matching exports or more than one,
/// it should return an empty <see cref="IEnumerable{T}"/> of <see cref="Export"/>.
/// </note>
/// </remarks>
protected override IEnumerable <Export>?GetExportsCore(ImportDefinition definition, AtomicComposition?atomicComposition)
{
ThrowIfDisposed();
IEnumerable <Export>?exports = null;
if (!definition.Metadata.TryGetValue(CompositionConstants.ImportSourceMetadataName, out object?source))
{
source = ImportSource.Any;
}
switch ((ImportSource)source !)
{
case ImportSource.Any:
if (_rootProvider == null)
{
throw new Exception(SR.Diagnostic_InternalExceptionMessage);
}
_rootProvider.TryGetExports(definition, atomicComposition, out exports);
break;
case ImportSource.Local:
if (_localExportProvider == null)
{
throw new Exception(SR.Diagnostic_InternalExceptionMessage);
}
_localExportProvider.TryGetExports(definition.RemoveImportSource(), atomicComposition, out exports);
break;
case ImportSource.NonLocal:
if (_ancestorExportProvider != null)
{
_ancestorExportProvider.TryGetExports(definition.RemoveImportSource(), atomicComposition, out exports);
}
break;
}
return(exports);
}
