@Override
  public JsonElement serialize(
      WebSocketMessage src, Type typeOfSrc, JsonSerializationContext context) {

    JsonObject root = new JsonObject();
    JsonObject jsonNodeData = new JsonObject();
    JsonObject jsonRelData = new JsonObject();
    JsonArray removedProperties = new JsonArray();
    JsonArray modifiedProperties = new JsonArray();

    if (src.getCommand() != null) {

      root.add("command", new JsonPrimitive(src.getCommand()));
    }

    if (src.getId() != null) {

      root.add("id", new JsonPrimitive(src.getId()));
    }

    if (src.getPageId() != null) {

      root.add("pageId", new JsonPrimitive(src.getPageId()));
    }

    if (src.getMessage() != null) {

      root.add("message", new JsonPrimitive(src.getMessage()));
    }

    if (src.getCode() != 0) {

      root.add("code", new JsonPrimitive(src.getCode()));
    }

    if (src.getSessionId() != null) {

      root.add("sessionId", new JsonPrimitive(src.getSessionId()));
    }

    if (src.getToken() != null) {

      root.add("token", new JsonPrimitive(src.getToken()));
    }

    if (src.getCallback() != null) {

      root.add("callback", new JsonPrimitive(src.getCallback()));
    }

    if (src.getButton() != null) {

      root.add("button", new JsonPrimitive(src.getButton()));
    }

    if (src.getParent() != null) {

      root.add("parent", new JsonPrimitive(src.getParent()));
    }

    if (src.getView() != null) {

      root.add("view", new JsonPrimitive(src.getView()));
    }

    if (src.getSortKey() != null) {

      root.add("sort", new JsonPrimitive(src.getSortKey()));
    }

    if (src.getSortOrder() != null) {

      root.add("order", new JsonPrimitive(src.getSortOrder()));
    }

    if (src.getPageSize() > 0) {

      root.add("pageSize", new JsonPrimitive(src.getPageSize()));
    }

    if (src.getPage() > 0) {

      root.add("page", new JsonPrimitive(src.getPage()));
    }

    JsonArray nodesWithChildren = new JsonArray();
    Set<String> nwc = src.getNodesWithChildren();

    if ((nwc != null) && !src.getNodesWithChildren().isEmpty()) {

      for (String nodeId : nwc) {

        nodesWithChildren.add(new JsonPrimitive(nodeId));
      }

      root.add("nodesWithChildren", nodesWithChildren);
    }

    // serialize session valid flag (output only)
    root.add("sessionValid", new JsonPrimitive(src.isSessionValid()));

    // UPDATE only, serialize only removed and modified properties and use the correct values
    if ((src.getGraphObject() != null)) {

      GraphObject graphObject = src.getGraphObject();

      if (!src.getModifiedProperties().isEmpty()) {

        for (PropertyKey modifiedKey : src.getModifiedProperties()) {

          modifiedProperties.add(toJsonPrimitive(modifiedKey));

          //					Object newValue = graphObject.getProperty(modifiedKey);
          //
          //					if (newValue != null) {
          //
          //						if (graphObject instanceof AbstractNode) {
          //
          //							src.getNodeData().put(modifiedKey.jsonName(), newValue);
          //						} else {
          //
          //							src.getRelData().put(modifiedKey.jsonName(), newValue);
          //						}
          //
          //					}

        }

        root.add("modifiedProperties", modifiedProperties);
      }

      if (!src.getRemovedProperties().isEmpty()) {

        for (PropertyKey removedKey : src.getRemovedProperties()) {

          removedProperties.add(toJsonPrimitive(removedKey));
        }

        root.add("removedProperties", removedProperties);
      }
    }

    // serialize node data
    if (src.getNodeData() != null) {

      for (Entry<String, Object> entry : src.getNodeData().entrySet()) {

        Object value = entry.getValue();
        String key = entry.getKey();

        if (value != null) {

          jsonNodeData.add(key, toJsonPrimitive(value));
        }
      }

      root.add("data", jsonNodeData);
    }

    // serialize relationship data
    if (src.getRelData() != null) {

      for (Entry<String, Object> entry : src.getRelData().entrySet()) {

        Object value = entry.getValue();
        String key = entry.getKey();

        if (value != null) {

          jsonRelData.add(key, toJsonPrimitive(value));
        }
      }

      root.add("relData", jsonRelData);
    }

    // serialize result list
    if (src.getResult() != null) {

      if (src.getView() != null) {

        try {
          propertyView.set(null, src.getView());

        } catch (FrameworkException fex) {

          logger.log(Level.WARNING, "Unable to set property view", fex);
        }

      } else {

        try {
          propertyView.set(null, PropertyView.Ui);

        } catch (FrameworkException fex) {

          logger.log(Level.WARNING, "Unable to set property view", fex);
        }
      }

      JsonArray result = new JsonArray();

      for (GraphObject obj : src.getResult()) {

        result.add(graphObjectSerializer.serialize(obj, System.currentTimeMillis()));
      }

      root.add("result", result);
      root.add("rawResultCount", toJsonPrimitive(src.getRawResultCount()));
    }

    // serialize result tree
    //		if (src.getResultTree() != null) {
    //
    //			TreeNode node = src.getResultTree();
    //
    //			root.add("root", buildTree(node, context));
    //
    //		}

    return root;
  }
  @Override
  public void processMessage(WebSocketMessage webSocketData) {

    final Map<String, Object> nodeData = webSocketData.getNodeData();
    final String parentId = (String) nodeData.get("parentId");
    final String pageId = webSocketData.getPageId();

    nodeData.remove("parentId");

    if (pageId != null) {

      // check for parent ID before creating any nodes
      if (parentId == null) {

        getWebSocket()
            .send(
                MessageBuilder.status()
                    .code(422)
                    .message("Cannot add node without parentId")
                    .build(),
                true);
        return;
      }

      // check if content node with given ID exists
      final DOMNode contentNode = getDOMNode(parentId);
      if (contentNode == null) {

        getWebSocket()
            .send(MessageBuilder.status().code(404).message("Parent node not found").build(), true);
        return;
      }

      final Document document = getPage(pageId);
      if (document != null) {

        final String tagName = (String) nodeData.get("tagName");
        nodeData.remove("tagName");

        final DOMNode parentNode = (DOMNode) contentNode.getParentNode();

        try {

          DOMNode elementNode = null;
          if (tagName != null && !tagName.isEmpty()) {

            elementNode = (DOMNode) document.createElement(tagName);
          }

          // append new node to parent parent node
          if (elementNode != null) {

            parentNode.appendChild(elementNode);
          }

          // append new node to parent parent node
          if (elementNode != null) {

            // append content node to new node
            elementNode.appendChild(contentNode);
          }

        } catch (DOMException dex) {

          // send DOM exception
          getWebSocket()
              .send(MessageBuilder.status().code(422).message(dex.getMessage()).build(), true);
        }

      } else {

        getWebSocket()
            .send(MessageBuilder.status().code(404).message("Page not found").build(), true);
      }

    } else {

      getWebSocket()
          .send(
              MessageBuilder.status()
                  .code(422)
                  .message("Cannot create node without pageId")
                  .build(),
              true);
    }
  }
  @Override
  public void processMessage(WebSocketMessage webSocketData) {

    final Map<String, Object> nodeData = webSocketData.getNodeData();
    final String parentId = (String) nodeData.get("parentId");
    final String childContent = (String) nodeData.get("childContent");
    final String pageId = webSocketData.getPageId();

    nodeData.remove("parentId");

    if (pageId != null) {

      // check for parent ID before creating any nodes
      if (parentId == null) {

        getWebSocket()
            .send(
                MessageBuilder.status()
                    .code(422)
                    .message("Cannot add node without parentId")
                    .build(),
                true);
        return;
      }

      // check if parent node with given ID exists
      final DOMNode parentNode = getDOMNode(parentId);
      if (parentNode == null) {

        getWebSocket()
            .send(MessageBuilder.status().code(404).message("Parent node not found").build(), true);
        return;
      }

      final Document document = getPage(pageId);
      if (document != null) {

        final String tagName = (String) nodeData.get("tagName");
        final App app = StructrApp.getInstance();

        nodeData.remove("tagName");

        try {
          app.beginTx();

          DOMNode newNode;

          if (tagName != null && !tagName.isEmpty()) {

            newNode = (DOMNode) document.createElement(tagName);

          } else {

            newNode = (DOMNode) document.createTextNode("#text");
          }

          // append new node to parent
          if (newNode != null) {

            parentNode.appendChild(newNode);

            for (Entry entry : nodeData.entrySet()) {

              String key = (String) entry.getKey();
              Object val = entry.getValue();

              PropertyKey propertyKey =
                  StructrApp.getConfiguration()
                      .getPropertyKeyForDatabaseName(newNode.getClass(), key);
              if (propertyKey != null) {

                try {
                  Object convertedValue = val;

                  PropertyConverter inputConverter =
                      propertyKey.inputConverter(SecurityContext.getSuperUserInstance());
                  if (inputConverter != null) {

                    convertedValue = inputConverter.convert(val);
                  }

                  // newNode.unlockReadOnlyPropertiesOnce();
                  newNode.setProperty(propertyKey, convertedValue);

                } catch (FrameworkException fex) {

                  logger.log(
                      Level.WARNING,
                      "Unable to set node property {0} of node {1} to {2}: {3}",
                      new Object[] {propertyKey, newNode.getUuid(), val, fex.getMessage()});
                }
              }
            }

            // create a child text node if content is given
            if (StringUtils.isNotBlank(childContent)) {

              DOMNode childNode = (DOMNode) document.createTextNode(childContent);

              if (newNode != null) {

                newNode.appendChild(childNode);
              }
            }
          }
          app.commitTx();

        } catch (DOMException dex) {

          // send DOM exception
          getWebSocket()
              .send(MessageBuilder.status().code(422).message(dex.getMessage()).build(), true);

        } catch (FrameworkException ex) {

          Logger.getLogger(CreateAndAppendDOMNodeCommand.class.getName())
              .log(Level.SEVERE, null, ex);

        } finally {

          app.finishTx();
        }

      } else {

        getWebSocket()
            .send(MessageBuilder.status().code(404).message("Page not found").build(), true);
      }

    } else {

      getWebSocket()
          .send(
              MessageBuilder.status()
                  .code(422)
                  .message("Cannot create node without pageId")
                  .build(),
              true);
    }
  }