CODEWITHSUNDEEP
javascriptangularjspromiseq
rolinger
rolinger

Reputation: 3068

javascript promise failing on then

Please help...what am I doing wrong.

In my controller I have this function that calls out to google's geocoder, I am trying to embed it into a promise to get the results properly returned in the $scope. I have gone through 20 different iterations and I still can't get it to work. The functions work, I am getting results...but I can't get the results into the $scope...when trying to encapsulate the geocoder into a promise it gives me errors Cannot read property 'then' of undefined 

   function getPosition(thisLat,thisLon) {
    // Retrieve address information based on Lat/Lng info

    var q = $q.defer() ;
    var thisLocation = getLL(thisLat,thisLon) ;
    var addressInfo = {};
    var notFound = 0 ;
    geoCoder.geocode({'latLng': thisLocation}, function(results, status) {
      if (status == google.maps.GeocoderStatus.OK) {
        for (var x=0;x<results.length;x++) {  
          var googleInfo = results[x].address_components ;
          for (var y=0;y<googleInfo.length;y++) {
            addressInfo.fullAddress = results[x].formatted_address;
            q.resolve(addressInfo) ;
          }        
        }
      } else {
        return q.reject("none" ) ;
      }
      return q.promise ;
    });
  }

  $scope.getEntrances = function() {
    for (var x=0;x<$scope.park.entrances.length;x++) {
     getPosition($scope.park.entrances[x].coordinates[0],$scope.park.entrances[x].coordinates[1])
     .then(function(result) {
         $scope.park.entrances[x].addressInfo = result ; 
      }) ;
    }
  }
  $scope.getEntrances() ;

Upvotes: 0

Views: 57

Answers (1)

Dacre Denny
Dacre Denny

Reputation: 30400

Try returning your promise q from the getPosition() function itself, rather than from in the geoCoder's callback function.

So in short, shift return q.promise; to the end of the getPosition() function like so: 

function getPosition(thisLat,thisLon) {
    // Retrieve address information based on Lat/Lng info

    var q = $q.defer() ;
    var thisLocation = getLL(thisLat,thisLon) ;
    var addressInfo = {};
    var notFound = 0 ;
    geoCoder.geocode({'latLng': thisLocation}, function(results, status) {
      if (status == google.maps.GeocoderStatus.OK) {
        for (var x=0;x<results.length;x++) {  
          var googleInfo = results[x].address_components ;
          for (var y=0;y<googleInfo.length;y++) {
            addressInfo.fullAddress = results[x].formatted_address;
            q.resolve(addressInfo) ;
            break; // [UPDATE] Avoid calling resolve on a promise multiple times
          }        
        }
      } else {
         q.reject("none" ) ; // [UPDATE] Don't need a return statement here
      }
    });

    // [UPDATE] return q.promise from here
    return q.promise ;
  }

Upvotes: 2

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