Streaming feature layers created from an ArcGIS Server stream service stream data updates as they occur. They are useful for visualizing real-time data feeds that have high volumes of data or that have data that changes at unknown intervals. For example, a fleet of vehicles might be transmitting their location, and the current location of the vehicles needs to be continuously monitored.
When you add a streaming feature layer to Map Viewer, you can use streaming controls to filter the data that the service sends to the layer. Apply a spatial filter so that only data within a certain map extent is sent to the layer. An attribute filter can also be set to limit what data is sent to the layer. For example, you might want to connect to a service that is sending out air quality information from sensors, but you only want to see information from sensors that are in your region of the country and where the concentration of a particulate is above a certain threshold.
Follow these steps to control streaming features in Map Viewer:
- In the Contents pane of Map Viewer, click the arrow next to the streaming feature layer.
- To apply a spatial filter to the layer, click Streaming controls and choose which spatial control you want to apply:
- Stop streaming or Start streaming—When you stop streaming, the layer stops drawing in Map Viewer and the data in the layer does not update until you start streaming again.
- Limit observations to current map area or Show all observations—Apply a spatial filter so that only data within a certain map extent is sent to the layer. Zoom to the extent you want and apply Limit observations to current map area. Even if you zoom out, features will only update within this extent. This filtering allows data to be more easily visualized and also prevents unneeded data from having to be sent through the network.
If you own the map and want to save this spatial filter, click Save.
When you want to see the whole layer again, click Show all observations.
- Clear previous observations—Use this option to clear the features from the map and begin streaming again. If you are limiting observations to the current map area, features will continue to stream in that area only.
- To apply an attribute filter to the layer, point to Filter and define a filter expression.