Initial geofence implementation

2 files changed, 76 insertions, 0 deletions

diff --git a/modern/src/map/GeofenceMap.js b/modern/src/map/GeofenceMap.js
new file mode 100644
index 0000000..965efaa
--- /dev/null
+++ b/modern/src/map/GeofenceMap.js
@@ -0,0 +1,59 @@
+import wellknown from 'wellknown';
+import { useEffect, useState } from 'react';
+
+import { map } from './Map';
+import { useEffectAsync } from '../reactHelper';
+import { reverseCoordinates } from './mapUtil';
+
+const GeofenceMap = () => {
+  const id = 'geofences';
+
+  const [geofences, setGeofences] = useState([]);
+
+  useEffectAsync(async () => {
+    const response = await fetch('/api/geofences');
+    if (response.ok) {
+      setGeofences(await response.json());
+    }
+  }, []);
+
+  useEffect(() => {
+    map.addSource(id, {
+      'type': 'geojson',
+      'data': {
+        type: 'FeatureCollection',
+        features: []
+      }
+    });
+    map.addLayer({
+      'id': id,
+      'type': 'fill',
+      'source': id,
+      'layout': {},
+      'paint': {
+      'fill-color': '#088',
+      'fill-opacity': 0.8
+      }
+    });
+
+    return () => {
+      map.removeLayer(id);
+      map.removeSource(id);
+    };
+  }, []);
+
+  useEffect(() => {
+    map.getSource(id).setData({
+      type: 'FeatureCollection',
+      features: geofences.map(item => [item.name, reverseCoordinates(wellknown(item.area))]).filter(([, geometry]) => !!geometry).map(([name, geometry]) => ({
+        type: 'Feature',
+        geometry: geometry,
+        properties: { name },
+      })),
+    });
+  }, [geofences]);
+
+  return null;
+}
+
+export default GeofenceMap;
diff --git a/modern/src/map/mapUtil.js b/modern/src/map/mapUtil.js
index 614234b..71d7b3c 100644
--- a/modern/src/map/mapUtil.js
+++ b/modern/src/map/mapUtil.js
@@ -50,3 +50,20 @@ export const calculateBounds = features => {
     return null;
   }
 }
+
+export const reverseCoordinates = it => {
+  if (!it) {
+    return it;
+  } else if (Array.isArray(it)) {
+    if (it.length === 2 && !Number.isNaN(it[0]) && !Number.isNaN(it[1])) {
+      return [it[1], it[0]];
+    } else {
+      return it.map(it => reverseCoordinates(it));
+    }
+  } else {
+    return {
+      ...it,
+      coordinates: reverseCoordinates(it.coordinates),
+    }
+  }
+}