API for locations within a certain radius from database

Question

I want to build a tool which allows me to search and locate my database (longitude and latitude users ), within a certain radius. i already have a googlemaps API key.

Is there a ready made tool or API ?. Any tips or suggestions?

here is my laravel code, so far i have fetched my db users as markers in map.

  #map {
    height: 50%;
  }

  html, body {
    height: 100%;
    margin: 0;
    padding: 0;
  }
</style>

<div id="map"></div>




<script>
    key=YOUR_API_KEY&libraries=places">

let users = ; console.log(users);

function initMap() { var myLatLng = {lat: 53.2193133, lng: 6.5669632};

      var map = new google.maps.Map(document.getElementById('map'), {
        zoom: 11,
        center: myLatLng
      });

      var markers = [];
      for (let i of users) {
        markers.push(
          new google.maps.Marker({
            position: {lat: parseFloat(i.latitude), lng: parseFloat(i.longitude)},
            map: map,
            title: i

            //hier wil ik eigelijk nog de naam van de gebruiker die vertoont wordt als je op de marker klikt. 
        }));


      }

      // var marker = new google.maps.Marker({
      //   position: myLatLng,
      //   map: map,
      //   title: 'Hello World!'
      // });
      // var marker2 = new google.maps.Marker({
      //   position: {lat: 53.2183133, lng: 6.5669632},
      //   map: map,
      //   title: 'Hello World!'
      // });


      // var myLatlng = new google.maps.LatLng(53.2193133,6.5669632);

      // var mapOptions = {
      //   zoom: 4,
      //   center: myLatlng
      // }
      // // var map = new google.maps.Map(document.getElementById("map"), mapOptions);

      // // var marker = new google.maps.Marker({
      // //   position: myLatlng,
      // //   title:"Hello World!"
      // });

}

// i was thinking to try something like this function to put in my controller

public function zoek(Request $request){

        $lat=$request ->lat;
        $lng=$request ->lng;

        $users=User::whereBetween('lat', [lat-0.05, lat+0.05])   ??

Not hard to find spatial radius formulas for whatever database you are using — charlietfl
What is the desired technology that you want to use to calculate the radius? This is not asked. What where your efforts, where did you fail? — michaeak

McMurphy McMurphy · Accepted Answer · 2019-01-02T03:56:00

I use a worker thread so as not to block the main-thread and make it interruptble to terminate a current search if a new set of search criteria is available.

In the mainline something like: -

function createFacilityMarkers(xmlhttp){
    facFinder = new Worker("facfinder.js");
    facFinder.addEventListener('message', workerInit, false);

    facFinder.postMessage({'cmd' : 'init', 'load' : xmlhttp.responseText});

facfinder.js looks like: -

importScripts("Tier3Toolbox.js");

var currVintage = 0;
var inBounds = false;
var facFilter = [];
var imageProlog = "<div style='height:5em; width:5em; display:inline-block;vertical-align:middle;'>" +
                  "<img style='height:100%; width: 100%; max-height:100%; max-width:100%' src='";
var imageEpilog = "' ></div>";
var facilityTable, lineBreak;

self.addEventListener('message', function(e) 
{
  var data = e.data;
  switch (data.cmd) {
    case 'init':
      initThread(data.load);
      break;
    case 'initFilter':
      for (var i=0; i<data.filterTable.length; i++) {
        facFilter[data.filterTable[i].locTypeId] = {'icon':data.filterTable[i].icon};
      }
      break;
    case 'filter':
      facFilter = [];
      for (var i=0; i<data.filterTable.length; i++) {
        if (data.filterTable[i].facSelected)
          facFilter[data.filterTable[i].locTypeId] = {'icon':data.filterTable[i].icon};
      }
      break;
    case 'search':
      var searchVintage = ++currVintage;
      var tableSearch = new searcher(searchVintage, data);
      break;
    case 'reset':
      reset();
      self.postMessage({'reset': true});
      break;
    case 'stop':
      self.postMessage({'success' : true});
      self.close(); 
      break;
    default:
      self.postMessage({'success' : false, 'msg' : data.msg});
  };
}, false);

function initThread(msg) 
{
    facilityTable = JSON.parse(msg);
    reset();

    self.postMessage({'success' : true, 
                      'cnt'     : facilityTable.length
                    });     
}   

function reset() 
{
    for (var i=0; i<facilityTable.length; i++) {
        facilityTable[i].visible=false
    }
    currVintage = 0;
}   

function searcher(searchVintage, msg)
{
    var myVintage = searchVintage;
    var facIndex  = -1;
    var msg       = msg;

    var checkLoop = function()
    {
        if (myVintage != currVintage)
            return;

        if (++facIndex == facilityTable.length)
            return;

        inBounds = geoFencer.call(this, msg);

        if (inBounds) {
            var facMatch = 0;
            var bubbleHTML = "";
            for (var i=0; i<facilityTable[facIndex].facilities.length; i++){
                var currFac = facilityTable[facIndex].facilities[i];
                if (facFilter[currFac.locTypeId] != undefined) {
                    if (facMatch != 0) {
                        lineBreak = (facMatch / 3);
                        if (lineBreak == lineBreak.toFixed(0)) {
                            bubbleHTML += "<br />";
                        }
                    }
                    facMatch++;
                    bubbleHTML += imageProlog + facFilter[currFac.locTypeId].icon + imageEpilog;

                }
            }
            if (facMatch == 0) {
                inBounds = false;
            }
        }

        if (inBounds != facilityTable[facIndex].visible) {
            self.postMessage({'match'       : inBounds,
                              'facIndex'    : facIndex,
                              'scopeVintage': msg.scopeVintage,
                              'bubbleHTML'  : bubbleHTML,
                              'success'     : true
                            }); 
            facilityTable[facIndex].visible = inBounds;
        }

        setTimeout(checkLoop,0);
    }

    var circleCheck = function(msg) 
    {
        var diff = Tier3Toolbox.calculateDistance(
                        msg.centerLat,
                        msg.centerLng,
                        facilityTable[facIndex].searchLat,
                        facilityTable[facIndex].searchLng);

        if (msg.radius > diff)
            return true;        

        return false;
    }

    var rectangleCheck = function(msg) 
    {
        if (facilityTable[facIndex].searchLat > msg.SWLat &&
            facilityTable[facIndex].searchLat < msg.NELat &&
            facilityTable[facIndex].searchLng > msg.SWLng &&
            facilityTable[facIndex].searchLng < msg.NELng)
            return true;        

        return false;
    }

    var GEOFENCER = [circleCheck,rectangleCheck];
    var geoFencer = GEOFENCER[msg.checker];

    setTimeout(checkLoop,0);
    return this;
}

And the calculateDistance function is: -

    Tier3Toolbox.calculateDistance =
    function(lat1, lon1, lat2, lon2){
        var dLat = this.toRad(lat2 - lat1);
        var dLon = this.toRad(lon2 - lon1);
        var a = Math.sin(dLat / 2) * Math.sin(dLat / 2) + Math.cos(this.toRad(lat1)) * 
                Math.cos(this.toRad(lat2)) * Math.sin(dLon / 2) * Math.sin(dLon / 2);
        var distance = this.EARTH_RADIUS * 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1 - a));
        return distance;
    }

API for locations within a certain radius from database

1 Answers