Google Maps Js Api V3: Get Markers In Circle With Containslocation() Doesn't Work - Why?

I'm trying to get all markers within a given radius (google.maps.Circle) by using google.maps.geometry.poly.containsLocation as recommended here, but I get an error: TypeError: e i

Solution 1:

containsLocation is a method on google.maps.Polygon objects not google.maps.Circle objects

To determine if a marker is within a circle use google.maps.geometry.spherical.computeDistanceBetween

if (google.maps.geometry.spherical.computeDistanceBetween(randomMarkers[i].marker.getPosition(), searchArea.getCenter()) <= searchArea.getRadius()) {
    console.log('=> is in searchArea');
} else {
    console.log('=> is NOT in searchArea');
}

working fiddle

working code snippet:

var map,
  searchArea,
  searchAreaMarker,
  searchAreaRadius = 1000, // metres
  startLat = 40.782827,
  startLng = -73.966167;

functioninit() {
  var startLatLng = new google.maps.LatLng(startLat, startLng);

  map = new google.maps.Map(document.getElementById('map-canvas'), {
    center: startLatLng,
    zoom: 12
  });

  searchArea = new google.maps.Circle({
    strokeColor: '#FF0000',
    strokeOpacity: 0.5,
    strokeWeight: 2,
    fillColor: '#FF0000',
    fillOpacity: 0.2,
    map: map,
    center: startLatLng,
    radius: searchAreaRadius
  });

  searchAreaMarker = new google.maps.Marker({
    position: startLatLng,
    map: map,
    draggable: true,
    animation: google.maps.Animation.DROP,
    title: 'searchAreaMarker'
  });

  var randomMarkers = [{
    title: 'Marker 1',
    latLng: new google.maps.LatLng(40.770088, -73.971146)
  }, {
    title: 'Marker 2',
    latLng: new google.maps.LatLng(40.782048, -73.972691)
  }, {
    title: 'Marker 3',
    latLng: new google.maps.LatLng(40.769048, -73.987797)
  }, {
    title: 'Marker 4',
    latLng: new google.maps.LatLng(40.773858, -73.956211)
  }, {
    title: 'Marker 5',
    latLng: new google.maps.LatLng(40.800372, -73.952091)
  }, {
    title: 'Marker 6',
    latLng: new google.maps.LatLng(40.804661, -73.939388)
  }];

  for (var i = 0; i < randomMarkers.length; i++) {
    randomMarkers[i].marker = new google.maps.Marker({
      position: randomMarkers[i].latLng,
      map: map,
      title: randomMarkers[i].title
    });
  }

  google.maps.event.addListener(searchAreaMarker, 'dragend', function(e) {
    startLatLng = e.latLng;

    searchArea.setOptions({
      center: startLatLng
    });

    map.panTo(searchAreaMarker.getPosition());
    findMarkersInArea();
  });
  var iwArray = [];
  functionfindMarkersInArea() {
    // close open infowindowsfor (var i=0; i<iwArray.length; i++) {
      iwArray[i].close();
    }
    iwArray = [];
    // find markers in areafor (var i = 0; i < randomMarkers.length; i++) {
      console.log('Marker: ' + randomMarkers[i].marker.title + ', position: ' + randomMarkers[i].marker.getPosition());
      console.log("marker["+i+"] posn="+randomMarkers[i].marker.getPosition().toUrlValue(6));
      if (google.maps.geometry.spherical.computeDistanceBetween(randomMarkers[i].marker.getPosition(), searchArea.getCenter()) <= searchArea.getRadius()) {
        console.log('=> is in searchArea');
        var iw = new google.maps.InfoWindow();
        iw.setContent("is in searchArea");
        iw.open(map, randomMarkers[i].marker);
        iwArray.push(iw);
      } else {
        console.log('=> is NOT in searchArea');
        var iw = new google.maps.InfoWindow();
        iw.setContent("outside searchArea");
        iw.open(map, randomMarkers[i].marker);
        iwArray.push(iw);
      }
    }
  }
  // initial configfindMarkersInArea();
}

google.maps.event.addDomListener(window, 'load', init);

html,
body,
#map-canvas {
  height: 100%;
  width: 100%;
  margin: 0px;
  padding: 0px
}

<scriptsrc="https://maps.googleapis.com/maps/api/js?libraries=geometry&key=AIzaSyCkUOdZ5y7hMm0yrcCQoCvLwzdM6M8s5qk"></script><divid="map-canvas"style="border: 2px solid #3872ac;"></div>

Solution 2:

The solution suggested by @Sumuray will create points also outside of the circle, but still in the bounds (square/rectangle) of the circle.

using the method he suggested:

// if HTML DOM Element that contains the map is found...if (document.getElementById('map-canvas')) {

  // Coordinates to center the mapvar myLatlng = new google.maps.LatLng(52.525595, 13.393085);

  // Other options for the map, pretty much selfexplanatoryvar mapOptions = {
    zoom: 14,
    center: myLatlng,
    mapTypeId: google.maps.MapTypeId.ROADMAP
  };

  // Attach a map to the DOM Element, with the defined settingsvar map = new google.maps.Map(document.getElementById("map-canvas"), mapOptions);
  var marker = new google.maps.Marker({
    map: map,
    position: myLatlng
  });
  var circle = new google.maps.Circle({
    map: map,
    radius: 1000,
    fillColor: '#AA0000',
    fillOpacity: 0.15,
    strokeWeight: 0.9,
    position: myLatlng
  });
  circle.bindTo('center', marker, 'position');

  var circleBounds = circle.getBounds();
  for (var i = 0; i < 50; i++) {
    var marker = generateMarkerInBoundries(circleBounds);
    marker.setMap(map);
  }

  functiongenerateMarkerInBoundries(boundries) {
    var marker = new google.maps.Marker();
    marker.setPosition(new google.maps.LatLng(0, 0));
    while (!boundries.contains(marker.position)) {
      var
        ne = boundries.getNorthEast(),
        sw = boundries.getSouthWest(),
        lat = randomFloat(ne.lat(), sw.lat()),
        lng = randomFloat(ne.lng(), sw.lng());
      marker.setPosition(new google.maps.LatLng(lat, lng))
    }
    return marker;
  }

  functionrandomFloat(min, max) {
    returnMath.random() * (max - min) + min;
  }

}

#map-canvas {
  height: 500px;
  width: 500px;
  border: 3px solid black;
}

<divid="map-canvas"></div><scriptsrc="https://maps.googleapis.com/maps/api/js?v=3.exp&sensor=false"type="text/javascript"></script>

You can clearly see that some of the markers are outside of the circle, but within the bounding box of the circle.

To fix the issue, you could use the geometry library and add a method to check if the point is within the circle's radius

// if HTML DOM Element that contains the map is found...if (document.getElementById('map-canvas')) {

  // Coordinates to center the mapvar myLatlng = new google.maps.LatLng(52.525595, 13.393085);

  // Other options for the map, pretty much selfexplanatoryvar mapOptions = {
    zoom: 14,
    center: myLatlng,
    mapTypeId: google.maps.MapTypeId.ROADMAP
  };

  // Attach a map to the DOM Element, with the defined settingsvar map = new google.maps.Map(document.getElementById("map-canvas"), mapOptions);
  var marker = new google.maps.Marker({
    map: map,
    position: myLatlng
  });
  var circle = new google.maps.Circle({
    map: map,
    radius: 1000,
    fillColor: '#AA0000',
    fillOpacity: 0.15,
    strokeWeight: 0.9,
    position: myLatlng
  });
  circle.bindTo('center', marker, 'position');

  var circleBounds = circle.getBounds();
  for (var i = 0; i < 50; i++) {
    var marker = generateMarkerInCircleRadius(circleBounds);
    marker.setMap(map);
  }

  functiongenerateMarkerInCircleRadius(boundries) {
    var marker = new google.maps.Marker();
    marker.setPosition(new google.maps.LatLng(0, 0));
    while (!isMarkerInRadius(marker, circle)) {
      var
        ne = boundries.getNorthEast(),
        sw = boundries.getSouthWest(),
        lat = randomFloat(ne.lat(), sw.lat()),
        lng = randomFloat(ne.lng(), sw.lng());
      marker.setPosition(new google.maps.LatLng(lat, lng))
    }
    return marker;
  }

  functionrandomFloat(min, max) {
    returnMath.random() * (max - min) + min;
  }

  functionisMarkerInRadius(marker, circle) {
    return google.maps.geometry.spherical.computeDistanceBetween(marker.getPosition(), circle.getCenter()) <= circle.getRadius();
  }
}

#map-canvas {
  height: 500px;
  width: 500px;
  border: 3px solid black;
}

<divid="map-canvas"></div><scriptsrc="https://maps.googleapis.com/maps/api/js?v=3.exp&libraries=geometry&sensor=false"type="text/javascript"></script>