如何实施承诺来处理多个Google Places API调用？

Question

我有一个Angular.js服务，可以从Google Places API中检索大量的地方搜索结果。然后，该服务继续为每个结果调用详细的位置请求。我试图将生成的JSON传递回控制器。

我认为由于API调用的异步性质，详细结果并非都返回。当我从ResultsActivity记录返回的位置时，我可以看到并非所有结果都存在。但是，我可以在控制台上看到在解析完承诺后返回结果。我试图实现多个promises和$ q.all（），但无济于事。

如果有人能指出我如何使用$q.all或建议更好的解决方法，我将不胜感激。

谢谢。

PlaceService：

// public/js/services/PlaceService.js

angular.module('Services').factory('PlaceService', ['$http', '$rootScope', '$location', '$q', function($http, $rootScope, $location, $q){

var map;
var service;
var infowindow;
var basicPlaces = [];
var places = [];

function getPlaces(lat, lng, radius){

    var deferred = $q.defer();
    var promises = [];

    function initialize(lat, lng, radius) {

        console.log('initialize');
        var pyrmont = new google.maps.LatLng(lat,lng);

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

        infowindow = new google.maps.InfoWindow();

        var request = {
            location: pyrmont,
            radius: radius,
            types: ['store']
        };

        service = new google.maps.places.PlacesService($("#results")[0]);
        service.nearbySearch(request, callback);
    }

    function callback(results, status) {
        if (status == google.maps.places.PlacesServiceStatus.OK) {
            for (var i = 0; i < results.length; i++) {
                var place = results[i];
                console.log(results[i]);
                $("#results").append('<p>'+results[i].name + '\n\n</p>');
                createMarker(results[i]);
                basicPlaces.push(place);
                var defer = $q.defer();
                promises.push(defer);
                service.getDetails({
                    placeId: results[i].place_id
            }, function(place, status) {
                    if (status === google.maps.places.PlacesServiceStatus.OK) {
                        console.log(place);
                        places.push(place);
                        console.log(places);
                        console.log(i);
                        if (i == results.length) {
                            console.log("deferring");
                            defer.resolve(place);
                        }
                    }
                });
           }
       }
   }

   function createMarker(place) {
        var placeLoc = place.geometry.location;
        var marker = new google.maps.Marker({
            map: map,
            position: place.geometry.location
        });

        google.maps.event.addListener(marker, 'click', function() {
            infowindow.setContent(place.name);
            infowindow.open(map, this);
        });
    }

    initialize(lat, lng, radius); 
    return $q.all(promises);
}

return {
    getPlaces
}
}]);

从ResultsActivity调用服务：

PlaceService.getPlaces($scope.latitude, $scope.longitude, $scope.radius).then(function(places){
    $scope.places = places; //Some detailed places are missing here
});