title: Google Map : InvalidValueError: setLabel: not a string; and no text property
body: <p>I am trying to create a google map with directions and for the purpose using Polyline. But I am getting the above console errors and I just can't get what is the problem here.
  Code : </p>
  
  <pre><code>&lt;script src="https://maps.googleapis.com/maps/api/js?sensor=false" type="text/javascript"&gt;&lt;/script&gt;
  var marker;
  var infowindow;
  var labels = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ';
  var labelIndex = 0;
  var markers = {};
  var currentId = 0;
  var uniqueId = function() {
      return ++currentId;
  }
  var edit = 0;
  var direction = '';
  var linecordinates = [];
  var map;
  var sortorder = 0;
  var latest_marker;
  var latest_latlng;
  var lineSymbol;
  var flightPath;
  var line = [];
  
  var saved_locations = $("#hidden_lat_long").val();
  // saved_locations = [{"label":1,"lat":"27.7233","long":"85.2783"},{"label":2,"lat":"27.7625","long":"85.3411"},{"label":3,"lat":"27.7056","long":"85.4166"},{"label":4,"lat":"27.6704","long":"85.3209"}]
  
  function initialize() {
      lineSymbol = {
          path: google.maps.SymbolPath.FORWARD_CLOSED_ARROW
      };
      /* edit portion */
      if(saved_locations != '') {
          edit = 1;
          saved_locations = JSON.parse(saved_locations);
          currentId = labelIndex = sortorder = saved_locations.length;
      }
      /* edit portion */
      var latlng = new google.maps.LatLng(27.7238,85.3214);
      var options = {
          zoom: 12,
          center: latlng,
          mapTypeId: google.maps.MapTypeId.ROADMAP
      }
      map = new google.maps.Map(document.getElementById("map-canvas"), options);
  
      /* edit portion */
      if(edit) {
          for( i = 0; i &lt; saved_locations.length; i++ ) {
              var position = new google.maps.LatLng(saved_locations[i].lat, saved_locations[i].long);
              var id = saved_locations[i].label;
  
              var saved_label = saved_locations[i].label;
              marker = new google.maps.Marker({
                  id: id,
                  position: position,
                  map: map,
                  label: saved_label,
              });
              console.log(marker);
              markers[id] = marker;
  
              linecordinates.push({
                  id: id,
                  lat: parseFloat(saved_locations[i].lat),
                  lng: parseFloat(saved_locations[i].long)
              });
          }
  
          flightPath = new google.maps.Polyline({
              path: linecordinates,
              strokeColor: '#FF0000',
              strokeOpacity: 1.0,
              strokeWeight: 2,
              icons: [{
                icon: lineSymbol,
                offset: '100%'
              }],
          });
          addline();
      }
      /* edit portion */
  }
  google.maps.event.addDomListener(window, 'load', initialize);
  function addline() {
      line.push(flightPath);
      flightPath.setMap(map);
  }
  &lt;div id="map-canvas"&gt;&lt;/div&gt;
  </code></pre>
  
  <p>Any help/suggestions are welcome.</p>