Update Features Linked to Survey Points, Using a Topology


This developer sample combines the topology graph and the survey point links to allow selected edges and nodes, and selected features, to be shifted to their corresponding survey point positions. The sample comprises two commands: the first works the same way as the existing Update command, but enhances it by making it aware of the topology graph and shifting the features adjoining the selected features correctly. The second command works with selected topology edges and nodes. By combining the technologies of Survey Analyst and Topology, these commands allow "linked" nodes or edges to update all the parent features. This means that you can manage fewer links for survey-aware feature classes in the topology, while still maintaining the topological relationships between the features in these feature classes. Additionally, this command will work with a map topology, so you do not need to create a geodatabase topology to take advantage of this sample.

How to use:
  1. In ArcMap, browse and select the UpdateByTopology.dll using the 'Add From File' button on the Customize dialog.
  2. From the 'Developer Samples Survey Analyst' commands category, add the 'Update Features in Topology...' command to the Survey Editor menu.
  3. From the 'Developer Samples Survey Analyst' commands category, add the 'Move To Survey Points' command to the Topology Edit Tool context menu.
  4. For the first command, select features using the Editor's Edit tool, click the Survey Editor menu, and click Update Features in Topology.
  5. In the dialog that appears check the first box if you want to ensure that the linked nodes are snapped to the survey points.
  6. Check the second box and select one of the available transformations to transform the nodes' vertices.
  7. Check the third box to get a report of the Root Mean Square (RMS) error for the transformation.
  8. For the second command, select nodes and edges using the Topology Edit Tool, right-click in the map to get the Topology Edit Tool context menu, and click Move To Survey Points.
  9. Note that the 'Move to Survey Points' command honors the settings for shared features, as well as the editor's 'Stretch Geometry Proportionately when Moving a Vertex' option.


Requires: A Topology Layer, or a Map Topology. An Edit Session, and Survey Analyst installed.

Minimum ArcGIS Version Required: 8.3

Difficulty: Advanced

Visual Basic
File Description
UpdateByTopology.vbp The project file for the sample Update Commands.
frmUpdateMethod.frm Dialog that allows you to choose the strategy for the feature update.
clsUpdateElements.cls Class that contains the source code for updating the selected topology elements.
clsUpdateFeatures.cls Class that contains the source code for updating the selected features in a topology.
clsTopologyFunctions.cls Class that contains the source code for commonly used topology functions.
clsSurveyAnalystFunctions.cls Class that contains the source code for survey analyst based functions.
UpdateByTopology.dll The compiled project.

Key CoClasses: SurveyDatasetExtension,
Key Interfaces: IEnumLayer, ILayer, ISurveyLayer, ISurveyDataset, IInvalidArea, IFeatureSurveyLinkCache, ISegmentCollection, IEnvelope, IEnumLinkInfo, ILinkInfo, IEnumTopologyEdge, IEnumTopologyParent, IFeature, IFeatureClass, ITopology, IMapTopology, ITopologyGraph, IAffineTransformation2D, IEditProperties