How do I build an workshop map-based app that allows users to
a) see the intersection of locations with circular areas (each called a “blast zone”) with predefined centroids
b) select a blast zone to see aggregated metrics about the locations it intersects
I have a map with layer for the locations using Geopoint types in my OT.
Now I want to overlay 10 blast zones with predefined centroids and 10km radius.
AIP Assist recommends using “vector layers and add your circle data as a GeoJSON File or Dataset GeoJSON File”, also noting that PB has a geometry buffer function handy for calculating the geojson properties.
That’s a lot for me to discover and experiment with, so I want to make sure I am on the right track.
You’re on the right track. I’d do the heavy lifting in Pipeline Builder rather than in Workshop:
Make a blast zone dataset (zone id + centroid). Use “Geometry buffer” to turn each centroid into the 10km circle - that’s your shape for the map layer.
Use a “Geometry distance join” between locations and zone centroids (10km) to get a location ↔ zone table. Careful with units - with epsg:4326 the distance is in degrees, so use a meter-based CRS. Also the join won’t take GeoPoint directly, so convert the points to geometry first.
In the Ontology, make Blast Zone an object type with the buffered shape as a geoshape property, and use the join table as a many-to-many link to Location.
In Workshop, show zones as a map layer. When a user selects a zone, search around to its linked locations and feed that into your metric cards.
Precomputing the intersections means the app doesn’t do geo math at runtime.