Question

我正在尝试分配一个变量 - ＆gt;从$ http请求中检索到的值。但是，用于变量的代码首先执行，而不是在使用promise之后等待http请求。

我是棱角分明但我认为并且承诺＆＃39;应该照顾好这个。请建议！

from django.db.models.signals import post_save

@receiver(post_save, sender=Voucher)
def decrease_quota(sender, instance, created, *args, **kwargs):
    if created:
        instance.vc -= 1
        instance.save()

Answer 1

这就是我的工作，而且效果很好。

Service.getData("param1", $scope.otherParam).then(
    function(data){
        console.log(data.data); //hey there it is... :)
        $scope.someOtherfunctionCallback(data.data);
    }
).finally(function(){ console.log("finally done with that crap..."); });

我的服务：

angular.module('app')
  .factory('Service',['$http','$q',function($http, $q){
var service={};
var getReportMenu = function(){
        //console.log("getting menu...");
        var defer = $q.defer();
            $http({
                method:'GET',               
                url:'http://localhost:8080/API/PATH',               
                cache:true,
                dataType:'json'})
            .then(
                function successCallback(response){
                    defer.resolve(response);
                },

                function errorCallback(response){
                    //TODO: handle this elegantly later.
                    alert("Error!");
                });
            return defer.promise;
        }

return { getReportMenu : getReportMenu }; //Just easy encapsulation.

}
});

Answer 2

$q.all([one]).then(function(arr) {
            $scope.providerinfo = arr;
            console.log(arr[0].data[0].AREA);
            $scope.image = arr[0].data[0].ProvImage;
            $scope.items = [{
             src: $scope.image,
             sub: 'This is a <b>subtitle</b>'
            }]
            console.log($scope.image); * * // This gives output as my required answer but SECOND --> Executed Second**
        },
        function(err) {

        }
    ).
    finally(
        function() {
            //Nothing
        })
    console.log($scope.image); * * // This gives output as undefined FIRST --> Executed first**
    $scope.items = [{
        src: $scope.image,
        sub: 'This is a <b>subtitle</b>'
    }]

Answer 3

你的第二个console.log（）首先运行，因为它不在你的诺言中。

你在做什么

$scope.items = [{
   src: $scope.image,
   sub: 'This is a <b>subtitle</b>'
}];

$ scope.image尚未提供，因为尚未履行承诺。将此代码移到promise中，它应该可以正常工作。

var one = providerdetailservice.getdetails($scope.whichProv);    
$q.all([one]).then(function(arr){
    $scope.providerinfo = arr;
    console.log(arr[0].data[0].AREA);
    $scope.image = arr[0].data[0].ProvImage;
    console.log($scope.image);

    //now try and access $scope.image
    $scope.items = [{
        src: $scope.image,
       sub: 'This is a <b>subtitle</b>'
    }];
}, function(err){}
).finally(function(){ //Nothing });

$ scope.variable在从$ http检索数据之前执行

3 个答案: