In my geocoder geocode callback, how do I determine which request the result corresponds to?

问题

I'm looping through about 60 addresses to get them geocoded for use on a Google Map. My callback (below) seems to work well for collecting the locations, but I need to know how to relate them to the address objects I'm looping through. I can't find anything in the geocode response that tells me which of my requests it 'came from.'

Is there a way to do that?

This is my function:

  geocode() {
    var lv_location;
    var geocoder = new google.maps.Geocoder();

    if (geocoder) {
        geocoder.geocode({'address' : this.address}, 
          function(results, status) {
                if (status == google.maps.GeocoderStatus.OK) {
                    // what data in results can be used to relate the location to the address?
                    lv_location = results[0].geometry.location;
                } 
                markerCounter++;
                if (markerCounter >= 60) finishSurnames();
        });
    }

回答1:

In JavaScript you can use Immediately-invoked function expression that will create a function scope also known as closure. You should change your function to something similar to

geocode() {
    var lv_location;
    var geocoder = new google.maps.Geocoder();

    if (geocoder) {
        geocoder.geocode({'address' : this.address}, (function(originalAddress){
            return function(results, status) {
                if (status == google.maps.GeocoderStatus.OK) {
                    // what data in results can be used to relate the location to the address?
                    //You can use the originalAddress variable here to relate result to request
                    lv_location = results[0].geometry.location;

                } 
                markerCounter++;
                if (markerCounter >= 60) finishSurnames();
            };
        })(this.address));
    }
}

Have a look at my example, it geocodes 3 addresses and print in console result and corresponding request string

var addresses = [
    'av Diagonal 197, Barcelona',
    'av Lucas Vega 53, San Cristobal de La Laguna',
    'Metrologichna 14, Kiev'
];

function initMap() {
  var map = new google.maps.Map(document.getElementById('map'), {
    zoom: 8,
    center: {lat: -34.397, lng: 150.644}
  });
  var geocoder = new google.maps.Geocoder();

  addresses.forEach( function(address) {
     geocode(geocoder, address);
  });
}

function geocode(geocoder, address) {
  geocoder.geocode({'address': address}, (function(originalAddress) {
    return function(results, status) {
      if (status === 'OK') {
        console.log("Search: " + originalAddress + "->" + results[0].geometry.location.toString());
      } else {
        console.log("Search: " + originalAddress + "->" + status);
      }
    };
  })(address));
}

#map {
  height: 100%;
}
html, body {
  height: 100%;
  margin: 0;
  padding: 0;
}

<div id="map"></div>
<script async defer
    src="https://maps.googleapis.com/maps/api/js?v=3&key=AIzaSyDztlrk_3CnzGHo7CFvLFqE_2bUKEq1JEU&callback=initMap">
    </script>

I hope this helps!

来源：https://stackoverflow.com/questions/47600136/in-my-geocoder-geocode-callback-how-do-i-determine-which-request-the-result-cor

标签

javascript

google-maps

google-maps-api-3

google-geocoder