javascript - AngularJS 访问 $http 之外

Question

请问，为什么我无法访问 $http 方法之外的 $scope.auditorium 但我可以访问其他 $http(例如 $scope.exhibition)在另一个 $http ($scope.auditorium) 中。通过 $scope.combine

在末尾连接 2 个作用域

代码:

      myApp.controller('displayCatController', ['$scope','$http', function($scope, $http){

              //Display auditoriums information
              $http({
                  method: 'GET',
                  url:'https://developers.onemap.sg/publicapi/themeapi/retrieveTheme?queryName=auditoriums&token=eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.eyJzdWIiOjMsInVzZXJfaWQiOjMsImVtYWlsIjoicHVibGljQXBpUm9sZUBzbGEuZ292LnNnIiwiZm9yZXZlciI6ZmFsc2UsImlzcyI6Imh0dHA6XC9cL29tMi5kZmUub25lbWFwLnNnXC9hcGlcL3YyXC91c2VyXC9zZXNzaW9uIiwiaWF0IjoxNTM4Mzc5ODU3LCJleHAiOjE1Mzg4MTE4NTcsIm5iZiI6MTUzODM3OTg1NywianRpIjoiMmUxZDI2NzM0YjkxYzg2N2Y4NDdkZjI1ZTVhMzQyMjgifQ.HUmGwWO7E1MJpFADcuQyVA0h6bR2Vkkp0BQrTfrEj0k'
                  }).then(function successCallback(response) {
                    $scope.auditoriums = response.data.SrchResults;
                  }, function errorCallback(response) {
                    console.log(response);
                  });



              //Display exhibitions information
              $http({
                        method: 'GET',
                  url: 'https://developers.onemap.sg/publicapi/themeapi/retrieveTheme?queryName=exhibitioncentres&token=eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.eyJzdWIiOjMsInVzZXJfaWQiOjMsImVtYWlsIjoicHVibGljQXBpUm9sZUBzbGEuZ292LnNnIiwiZm9yZXZlciI6ZmFsc2UsImlzcyI6Imh0dHA6XC9cL29tMi5kZmUub25lbWFwLnNnXC9hcGlcL3YyXC91c2VyXC9zZXNzaW9uIiwiaWF0IjoxNTM4Mzc5ODU3LCJleHAiOjE1Mzg4MTE4NTcsIm5iZiI6MTUzODM3OTg1NywianRpIjoiMmUxZDI2NzM0YjkxYzg2N2Y4NDdkZjI1ZTVhMzQyMjgifQ.HUmGwWO7E1MJpFADcuQyVA0h6bR2Vkkp0BQrTfrEj0k'
                        }).then(function successCallback(response) {
                            $scope.exhibitions = response.data.SrchResults;
                    $scope.exhibitions.splice(0,1);
                        }, function errorCallback(response) {
                            console.log(response);
                        });

                    $scope.combine = $scope.exhibitions.concat($scope.auditoriums, $scope.hotels);
                    console.log($scope.combine);
      }]);

我无法访问 $scope.combine，它什么也不显示。但另一方面，如果我将 $scope 放在 $http 内，示例如下:

      myApp.controller('displayCatController', ['$scope','$http', function($scope, $http){

              //Display auditoriums information
              $http({
                  method: 'GET',
                  url:'https://developers.onemap.sg/publicapi/themeapi/retrieveTheme?queryName=auditoriums&token=eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.eyJzdWIiOjMsInVzZXJfaWQiOjMsImVtYWlsIjoicHVibGljQXBpUm9sZUBzbGEuZ292LnNnIiwiZm9yZXZlciI6ZmFsc2UsImlzcyI6Imh0dHA6XC9cL29tMi5kZmUub25lbWFwLnNnXC9hcGlcL3YyXC91c2VyXC9zZXNzaW9uIiwiaWF0IjoxNTM4Mzc5ODU3LCJleHAiOjE1Mzg4MTE4NTcsIm5iZiI6MTUzODM3OTg1NywianRpIjoiMmUxZDI2NzM0YjkxYzg2N2Y4NDdkZjI1ZTVhMzQyMjgifQ.HUmGwWO7E1MJpFADcuQyVA0h6bR2Vkkp0BQrTfrEj0k'
                  }).then(function successCallback(response) {
                    $scope.auditoriums = response.data.SrchResults;
                  }, function errorCallback(response) {
                    console.log(response);
                  });


              //Display exhibitions information
              $http({
                        method: 'GET',
                  url: 'https://developers.onemap.sg/publicapi/themeapi/retrieveTheme?queryName=exhibitioncentres&token=eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.eyJzdWIiOjMsInVzZXJfaWQiOjMsImVtYWlsIjoicHVibGljQXBpUm9sZUBzbGEuZ292LnNnIiwiZm9yZXZlciI6ZmFsc2UsImlzcyI6Imh0dHA6XC9cL29tMi5kZmUub25lbWFwLnNnXC9hcGlcL3YyXC91c2VyXC9zZXNzaW9uIiwiaWF0IjoxNTM4Mzc5ODU3LCJleHAiOjE1Mzg4MTE4NTcsIm5iZiI6MTUzODM3OTg1NywianRpIjoiMmUxZDI2NzM0YjkxYzg2N2Y4NDdkZjI1ZTVhMzQyMjgifQ.HUmGwWO7E1MJpFADcuQyVA0h6bR2Vkkp0BQrTfrEj0k'
                        }).then(function successCallback(response) {
                            $scope.exhibitions = response.data.SrchResults;
                    $scope.exhibitions.splice(0,1);
                $scope.combine = $scope.exhibitions.concat($scope.auditoriums, $scope.hotels);
                console.log($scope.combine);
                        }, function errorCallback(response) {
                            console.log(response);
                        });



      }]);

如果问题很愚蠢，请原谅我，我对 AngularJS 还很陌生。感谢您的帮助!

Answer 1

$http 服务将异步运行，而您的 $scope.combine 声明将同步运行并在异步操作完成之前进行设置。这就是为什么这些值是空的。

解决此问题的一个选择是等待所有异步操作完成。

这是一个例子

myApp.controller('displayCatController', ['$scope','$http','$q', function($scope, $http, $q){

              //Display auditoriums information
              var promise1 = $http({
                  method: 'GET',
                  url:'https://developers.onemap.sg/publicapi/themeapi/retrieveTheme?queryName=auditoriums&token=eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.eyJzdWIiOjMsInVzZXJfaWQiOjMsImVtYWlsIjoicHVibGljQXBpUm9sZUBzbGEuZ292LnNnIiwiZm9yZXZlciI6ZmFsc2UsImlzcyI6Imh0dHA6XC9cL29tMi5kZmUub25lbWFwLnNnXC9hcGlcL3YyXC91c2VyXC9zZXNzaW9uIiwiaWF0IjoxNTM4Mzc5ODU3LCJleHAiOjE1Mzg4MTE4NTcsIm5iZiI6MTUzODM3OTg1NywianRpIjoiMmUxZDI2NzM0YjkxYzg2N2Y4NDdkZjI1ZTVhMzQyMjgifQ.HUmGwWO7E1MJpFADcuQyVA0h6bR2Vkkp0BQrTfrEj0k'
                  }).then(function successCallback(response) {
                    $scope.auditoriums = response.data.SrchResults;
                  }, function errorCallback(response) {
                    console.log(response);
                  });


              //Display exhibitions information
              var promise2 =$http({
                        method: 'GET',
                  url: 'https://developers.onemap.sg/publicapi/themeapi/retrieveTheme?queryName=exhibitioncentres&token=eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.eyJzdWIiOjMsInVzZXJfaWQiOjMsImVtYWlsIjoicHVibGljQXBpUm9sZUBzbGEuZ292LnNnIiwiZm9yZXZlciI6ZmFsc2UsImlzcyI6Imh0dHA6XC9cL29tMi5kZmUub25lbWFwLnNnXC9hcGlcL3YyXC91c2VyXC9zZXNzaW9uIiwiaWF0IjoxNTM4Mzc5ODU3LCJleHAiOjE1Mzg4MTE4NTcsIm5iZiI6MTUzODM3OTg1NywianRpIjoiMmUxZDI2NzM0YjkxYzg2N2Y4NDdkZjI1ZTVhMzQyMjgifQ.HUmGwWO7E1MJpFADcuQyVA0h6bR2Vkkp0BQrTfrEj0k'
                        }).then(function successCallback(response) {
                            $scope.exhibitions = response.data.SrchResults;
                            $scope.exhibitions.splice(0,1);
                        }, function errorCallback(response) {
                            console.log(response);
                        });


            $q.all([promise1, promise2]).then(function(){
                $scope.combine = $scope.exhibitions.concat($scope.auditoriums, $scope.hotels);
                console.log($scope.combine);
            });

}]);