Angularjs数据是从在范围异步服务空 [英] Angularjs data is null from async service in scope

问题描述

在预先感谢阅读我的文章。

thanks in advance for read my post.

我有一个服务，是这样的：

I have a service, like this:

angular.module('myApp.services')
.factory('myService', function($http, $q) {
    var myService = {
        getId: function() {
            var defer = $q.defer();

            $http.get('http://xxxxxxxxxxxxxxxxxx/id/')
            .success( function(data) {
                defer.resolve(data);
            })
            .error( function(data) {
                defer.reject(data);
            });

            return defer.promise;
        },
        begin : function(jsonBegin) {
            var defer = $q.defer();

            $http.post('http://xxxxxxxxxxxxxxxxxxxxxxx/begin/?format=json', jsonBegin)
            .success( function(data) {
                defer.resolve(data);
            })
            .error( function(data) {
                defer.reject(data);
            });

            return defer.promise;
        }
    };

    return myService;
});

一个父控制器（正常工作）：

A parent controller (works fine):

angular.module('myApp.controllers')
.controller('controllerA', function($scope, myService) {
    myService.getId()
        .then(function(data) {
            $scope.bID = data.bID;
        });
});

和子控制器：

angular.module('myApp.controllers')
.controller('controllerB', function($scope) {
    console.log($scope.$parent.bID);
});

有关申办的console.log值是不确定的，做ü知道为什么吗？我设置了家长控制槽为myService服务，变量。我想我的问题是由于异步调用，但我不知道。

The console.log value for bID is undefined, do u know why? I am setting that variable in the parent controller trough myService service. I guess my problem is due to the asynchronous call but I'm not sure.

感谢。

推荐答案

您可以做这样的事情：

     angular.module('myApp.controllers')
        .controller('controllerA', function($scope, myService) {
            $scope.bID = myService.getId()
                .then(function(data) {
                    return data.bID;
                });
        });

    angular.module('myApp.controllers')
        .controller('controllerB', function($scope) {
            $scope.$parent.bID.then(function(bID) { console.log(bID); });
        });

子范围将等待家长来解决竞标。而当家长出价已解决，将立即在子作用域承诺返回值。这是一个有点杂乱，虽然期待。

The child scope will wait for the parent to resolve bID. And when parent bID is already resolved, it will immediately return the value in the child scope promise. It's a little messy looking though.

另一种方法是让控制器加载前为myService要求的决心。检查了这一点：

The alternative is to have the myService request resolve before the controller loads. Check this out:

的http://www.$c$clord.net/2015/06/02/angularjs-pitfalls-using-ui-routers-resolve/

然后就可以设置父范围解析值并访问其作为子作用域正常的财产。

Then you can set the parent scope to the resolved value and access it as a normal property in the child scope.

这篇关于Angularjs数据是从在范围异步服务空的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！