@salo/interactive-map/helpers/index.js

An SVG interactive map

import _forEachInstanceProperty from "@babel/runtime-corejs3/core-js-stable/instance/for-each";
import _mapInstanceProperty from "@babel/runtime-corejs3/core-js-stable/instance/map";
import _filterInstanceProperty from "@babel/runtime-corejs3/core-js-stable/instance/filter";
import _concatInstanceProperty from "@babel/runtime-corejs3/core-js-stable/instance/concat";
import _toConsumableArray from "@babel/runtime-corejs3/helpers/toConsumableArray";
import _sortInstanceProperty from "@babel/runtime-corejs3/core-js-stable/instance/sort";
import _reduceInstanceProperty from "@babel/runtime-corejs3/core-js-stable/instance/reduce";
import _isEmpty from "lodash/isEmpty";
import _indexOf from "lodash/indexOf";

/**
 * EVALUATE COORDINATES FROM LATITUDE & LONGITUDE
 *
 * @param {*} { lat, lon }
 * @returns
 */
export var evalCoordinates = function evalCoordinates(_ref) {
  var lat = _ref.lat,
      lon = _ref.lon;
  // lat = N - S
  // lon = W - E
  var x = 0;
  var y = 0;
  var mapWidth = 1717;
  var mapHeight = 1291; // get x value

  x = (lon + 180) * (mapWidth / 360) / mapWidth * 100 - 2.75; // convert from degrees to radians

  var latRad = lat * Math.PI / 180; // get y value

  var mercN = Math.log(Math.tan(Math.PI / 4 + latRad / 2));
  y = (mapHeight / 2 - mapWidth * mercN / (2 * Math.PI)) / mapHeight * 100 - 0.85;
  return {
    x: x,
    y: y
  };
};
/**
 * EVALUATE CENTER OF AN ARRAY OF COORDINATES
 *
 * @param {*} { locations: [{ lat: Float, lon: Float }] }
 * @returns
 */

export var evalCenter = function evalCenter(_ref2) {
  var locations = _ref2.locations;
  if (_isEmpty(locations)) return null; // Reduce lats and longs to get array of all location coords

  var aggData = _reduceInstanceProperty(locations).call(locations, function (acc, item) {
    var _context, _context2, _context3, _context4;

    return {
      lats: _sortInstanceProperty(_context = _concatInstanceProperty(_context2 = []).call(_context2, _toConsumableArray(acc.lats), [item.lat])).call(_context),
      // sort so they are in order
      lons: _sortInstanceProperty(_context3 = _concatInstanceProperty(_context4 = []).call(_context4, _toConsumableArray(acc.lons), [item.lon])).call(_context3)
    };
  }, {
    lats: [],
    lons: []
  });

  var centerLat = (aggData.lats[0] + aggData.lats[aggData.lats.length - 1]) / 2; // take limits and calculate the range

  var centerLon = (aggData.lons[0] + aggData.lons[aggData.lons.length - 1]) / 2;
  return {
    lat: centerLat,
    lon: centerLon
  };
};
/**
 * GROUP LOCATIONS BY LATITUDE
 *
 * @param {*} { locations, radius = 5, zoom = 1 }
 * @returns
 */

export var groupPoints = function groupPoints(_ref3) {
  var _context5;

  var locations = _ref3.locations,
      _ref3$radius = _ref3.radius,
      radius = _ref3$radius === void 0 ? 5 : _ref3$radius,
      _ref3$zoom = _ref3.zoom,
      zoom = _ref3$zoom === void 0 ? 1 : _ref3$zoom;
  var mappedLocations = [];
  var latResolution = zoom ? radius / 2 / zoom : 2.5;
  var lonResolution = zoom ? radius / zoom : 5;
  return _filterInstanceProperty(_context5 = _mapInstanceProperty(locations).call(locations, function (location) {
    // Check if location already grabbed as part of an
    // earlier grouping and only proceed if not grouped
    var alreadyMapped = _indexOf(mappedLocations, location);

    if (alreadyMapped === -1) {
      mappedLocations.push(location);
      var groupedLocations = [location];

      var remainingLocations = _filterInstanceProperty(locations).call(locations, function (item) {
        return _indexOf(mappedLocations, item) === -1;
      });

      _forEachInstanceProperty(remainingLocations).call(remainingLocations, function (item) {
        // CHECK IF LOCATION COLLIDES WITH ANOTHER
        var latCollision = location.lat - item.lat < latResolution && location.lat - item.lat > -latResolution;
        var lonCollision = location.lon - item.lon < lonResolution && location.lon - item.lon > -lonResolution;

        if (latCollision && lonCollision) {
          // EXCLUDE FROM A LATER MAP AND STORE
          mappedLocations.push(item);
          groupedLocations.push(item);
        }
      });

      var _evalCenter = evalCenter({
        locations: groupedLocations
      }),
          lat = _evalCenter.lat,
          lon = _evalCenter.lon;

      var _evalCoordinates = evalCoordinates({
        lat: lat,
        lon: lon
      }),
          x = _evalCoordinates.x,
          y = _evalCoordinates.y;

      return {
        lat: lat,
        lon: lon,
        x: x,
        y: y,
        points: groupedLocations
      };
    }

    return null;
  })).call(_context5, function (i) {
    return i;
  });
};