class/System.ComponentModel.Composition/src/ComponentModel/System/ComponentModel/Composition/Hosting/CompositionBatch.SingleExportComposablePart.cs

   1 // -----------------------------------------------------------------------
   2 // Copyright (c) Microsoft Corporation.  All rights reserved.
   3 // -----------------------------------------------------------------------
   4 using System;
   5 using System.Collections.Generic;
   6 using System.ComponentModel.Composition.Primitives;
   7 using System.Linq;
   8 using Microsoft.Internal;
   9
  10 namespace System.ComponentModel.Composition.Hosting
  11 {
  12     partial class CompositionBatch
  13     {
  14         // Represents a part that exports a single export
  15         private class SingleExportComposablePart : ComposablePart
  16         {
  17             private readonly Export _export;
  18
  19             public SingleExportComposablePart(Export export)
  20             {
  21                 Assumes.NotNull(export);
  22
  23                 this._export = export;
  24             }
  25
  26             public override IDictionary<string, object> Metadata
  27             {
  28                 get { return MetadataServices.EmptyMetadata; }
  29             }
  30
  31             public override IEnumerable<ExportDefinition> ExportDefinitions
  32             {
  33                 get { return new ExportDefinition[] { _export.Definition }; }
  34             }
  35
  36             public override IEnumerable<ImportDefinition> ImportDefinitions
  37             {
  38                 get { return Enumerable.Empty<ImportDefinition>(); }
  39             }
  40
  41             public override object GetExportedValue(ExportDefinition definition)
  42             {
  43                 Requires.NotNull(definition, "definition");
  44
  45                 if (definition != _export.Definition)
  46                 {
  47                     throw ExceptionBuilder.CreateExportDefinitionNotOnThisComposablePart("definition");
  48                 }
  49
  50                 return _export.Value;
  51             }
  52
  53             public override void SetImport(ImportDefinition definition, IEnumerable<Export> exports)
  54             {
  55                 Requires.NotNull(definition, "definition");
  56                 Requires.NotNullOrNullElements(exports, "exports");
  57
  58                 throw ExceptionBuilder.CreateImportDefinitionNotOnThisComposablePart("definition");
  59             }
  60         }
  61     }
  62 }