Improvement in Subs and FireMap Union

imports/ui/components/Maps/SubsUnion/SubsUnion.js

@@ -0,0 +1,78 @@
+/* eslint-disable react/jsx-indent-props */
+/* eslint-disable import/no-absolute-path */
+/* eslint-disable import/no-absolute-path */
+/* global L */
+
+import { Map } from 'react-leaflet';
+import LGeo from 'leaflet-geodesy';
+import tunion from '@turf/union';
+import { check, Match } from 'meteor/check';
+
+// https://stackoverflow.com/questions/35394577/leaflet-js-union-merge-circles
+
+function unify(polyList) {
+  let unionTemp;
+  for (let i = 0; i < polyList.length; i += 1) {
+    if (i === 0) {
+      unionTemp = polyList[i].toGeoJSON();
+    } else {
+      unionTemp = tunion(unionTemp, polyList[i].toGeoJSON());
+    }
+  }
+  return unionTemp;
+}
+
+const subsUnion = (union, options) => {
+  // check(union, Match.Optional(Object));
+  check(options, {
+    map: Map,
+    show: Boolean,
+    subs: [Object],
+    color: Match.Optional(String),
+    fillcolor: Match.Optional(String),
+    opacity: Match.Optional(Number),
+    fit: Boolean
+  });
+
+  const color = options.color || '#145A32';
+  const fillColor = options.fillColor || 'green';
+  const opacity = options.options || 0.1;
+
+  if (options.subs.length > 0) {
+    const lmap = options.map.leafletElement;
+    // http://leafletjs.com/reference-1.2.0.html#layergroup
+    // FeatureGroup has getBounds
+    const unionGroup = new L.FeatureGroup();
+
+    if (union) {
+      lmap.removeLayer(union);
+    }
+    union = null;
+
+    if (options.show) {
+      // http://leafletjs.com/reference-1.2.0.html#path
+      const copts = {
+        parts: 144
+      };
+      options.subs.forEach((sub) => {
+        const circle = LGeo.circle([sub.location.lat, sub.location.lon], sub.distance * 1000, copts);
+        circle.addTo(unionGroup);
+      });
+      const unionJson = unify(unionGroup.getLayers());
+      union = L.geoJson(unionJson);
+      union.setStyle({
+        color,
+        fillColor,
+        fillOpacity: opacity
+      });
+      union.addTo(lmap);
+      if (options.fit) {
+        options.map.leafletElement.fitBounds(unionGroup.getBounds());
+      }
+      return union;
+    }
+  }
+  return union;
+};
+
+export default subsUnion;