[AGD-1882] Support storing user defined graph documentation

src/DynamoCore/Graph/Workspaces/SerializationConverters.cs

@@ -649,6 +649,19 @@ public override object ReadJson(JsonReader reader, Type objectType, object exist
 
             ws.NodeLibraryDependencies = nodeLibraryDependencies.ToList();
             ws.ExtensionData = GetExtensionData(serializer, obj);
+            if (obj.TryGetValue(nameof(WorkspaceModel.Thumbnail), StringComparison.OrdinalIgnoreCase, out JToken thumbnail))
+                ws.Thumbnail = thumbnail.ToString();
+
+            if (obj.TryGetValue(nameof(WorkspaceModel.GraphDocumentationURL), StringComparison.OrdinalIgnoreCase, out JToken helpLink))
+            {
+                if (Uri.TryCreate(helpLink.ToString(), UriKind.Absolute, out Uri uri))
+                    ws.GraphDocumentationURL = uri;
+            }
+
+
+            if (obj.TryGetValue(nameof(WorkspaceModel.Author), StringComparison.OrdinalIgnoreCase, out JToken author))
+                ws.Author = author.ToString();
+
 
             return ws;
         }
@@ -771,6 +784,18 @@ public override void WriteJson(JsonWriter writer, object value, JsonSerializer s
             writer.WritePropertyName(WorkspaceReadConverter.EXTENSION_WORKSPACE_DATA);
             serializer.Serialize(writer, ws.ExtensionData);
 
+            // Thumbnail
+            writer.WritePropertyName(nameof(WorkspaceModel.Thumbnail));
+            writer.WriteValue(ws.Thumbnail);
+
+            // GraphDocumentaionLink
+            writer.WritePropertyName(nameof(WorkspaceModel.GraphDocumentationURL));
+            writer.WriteValue(ws.GraphDocumentationURL);
+
+            // Graph Author
+            writer.WritePropertyName(nameof(WorkspaceModel.Author));
+            writer.WriteValue(ws.Author);
+
             if (engine != null)
             {
                 // Bindings

src/DynamoCore/Graph/Workspaces/WorkspaceModel.cs

@@ -203,6 +203,8 @@ internal int CurrentPasteOffset
         private DateTime lastSaved;
         private string author = "None provided";
         private string description;
+        private string thumbnail;
+        private Uri graphDocumentationURL;
         private bool hasUnsavedChanges;
         private bool isReadOnly;
         private readonly List<NodeModel> nodes;
@@ -724,6 +726,46 @@ public string Description
             }
         }
 
+        /// <summary>
+        /// Link to documentation page for this workspace
+        /// </summary>
+        public Uri GraphDocumentationURL
+        {
+            get { return graphDocumentationURL; }
+            set 
+            {
+                if (graphDocumentationURL == value)
+                    return;
+
+                graphDocumentationURL = value;
+                RaisePropertyChanged(nameof(GraphDocumentationURL));
+            }
+        }
+
+
+        /// <summary>
+        /// Workspace thumbnail as Base64 string.
+        /// Returns null if provide value is not Base64 encoded.
+        /// </summary>
+        public string Thumbnail
+        {
+            get { return thumbnail; }
+            set
+            {
+                try
+                {
+                    // if value is not a valid Base64 string this will throw, and we return null.
+                    byte[] data = Convert.FromBase64String(value);
+                    thumbnail = value;
+                    RaisePropertyChanged(nameof(Thumbnail));
+                }
+                catch
+                {
+                    return;
+                }
+            }
+        }
+
         /// <summary>
         /// List of user defined data from extensions and view extensions stored in the graph
         /// </summary>

test/DynamoCoreTests/Graph/Workspaces/WorkspaceModelTests.cs

@@ -284,5 +284,35 @@ public void UpdateModelValueInvalidParameters()
             Assert.AreEqual(Resources.ModelNotFoundError, ex3.Message);
 
         }
+
+        [Test]
+        public void CanStoreBase64EncodedImageInThumbnailProperty()
+        {
+            // Arrange
+            var imagePath = Path.Combine(TestDirectory, @"DynamoCoreTests\Graph\Workspaces\thumbnailTestImage.png");
+            Assert.That(File.Exists(imagePath));
+
+            // Act
+            byte[] imageArray = System.IO.File.ReadAllBytes(imagePath);
+            string base64ImageRepresentation = Convert.ToBase64String(imageArray);
+            this.CurrentDynamoModel.CurrentWorkspace.Thumbnail = base64ImageRepresentation;
+
+            // Assert
+            Assert.NotNull(base64ImageRepresentation);
+            Assert.AreEqual(this.CurrentDynamoModel.CurrentWorkspace.Thumbnail, base64ImageRepresentation);
+        }
+
+        [Test]
+        public void WillNotStoreInvalidBase64StringInThumbnailProperty()
+        {
+            // Arrange
+            var invalidImagePath = "GenericString";
+
+            // Act
+            this.CurrentDynamoModel.CurrentWorkspace.Thumbnail = invalidImagePath;
+
+            // Assert
+            Assert.IsNull(this.CurrentDynamoModel.CurrentWorkspace.Thumbnail);
+        }
     }
 }