AngularJS 从服务加载数据 [英] AngularJS Load Data from Service

问题描述

我在从填充到我的视图中的服务获取数据时遇到问题.我有一个这样定义的服务

I am having a problem getting data from a service populated into my view. I have a service defined as such

app.factory('nukeService', function($rootScope, $http) {
    var nukeService = {};

    nukeService.nuke = {};

    //Gets the list of nuclear weapons
    nukeService.getNukes = function() {
        $http.get('nukes/nukes.json')
            .success(function(data) {
                nukeService.nukes = data;
            });

        return nukeService.nukes;
    };

    return nukeService;
});

和我的控制器

function NavigationCtrl($scope, $http, nukeService){



    /*$http.get('nukes/nukes.json').success(function(data) {
        $scope.nukes = data;
    });*/

    $scope.nukes = nukeService.getNukes();

}

如果我使用控制器中的 $http.get 数据填充得很好，但是，如果我尝试从服务调用数据，我什么也得不到.我知道查询是异步的，但我很难理解如何在返回数据后填充 $scope 变量.我可以使用 $rootscope 广播一个事件并在控制器中侦听它，但这似乎不是实现此目的的正确方法.我真的很感激关于如何以正确的方式做到这一点的任何建议.

If I use the $http.get from the controller the data populates fine, however, if I try to call the data from the service, I get nothing. I understand that the query is asynchronous but I am having a hard time understanding how to populate the $scope variable once the data is returned. I could use $rootscope to broadcast an event and listen for it in the controller but this does not seem like the correct way to accomplish this. I would really appreciate any advice on how to do this the correct way.

推荐答案

我认为这应该可以解决您的问题

I think this should solve your problem

app.factory('nukeService', function($rootScope, $http) {
    var nukeService = {};

    nukeService.data = {};

    //Gets the list of nuclear weapons
    nukeService.getNukes = function() {
        $http.get('nukes/nukes.json')
            .success(function(data) {
                nukeService.data.nukes = data;
            });

        return nukeService.data;
    };

    return nukeService;
});

function NavigationCtrl($scope, $http, nukeService){

    $scope.data = nukeService.getNukes();

    //then refer to nukes list as `data.nukes`

}

这是对象引用的问题.

当您调用 nukeService.getNukes() 时，您将获得对对象 a 的引用，然后您的变量 $scope.nukes 引用该对象内存位置.

when you calls nukeService.getNukes() you are getting a reference to a object a then your variable $scope.nukes refers that memory location.

在远程服务器调用后，当您设置 nukeService.nukes = data; 时，您不会更改对象 a 而是更改 nukeService.nukes 从引用对象 a 到对象 b.但是你的 $scope.nukes 不知道这个重新分配，它仍然指向对象 a.

After the remote server call when you set nukeService.nukes = data; you are not changing the object a instead you are changing nukeService.nukes from referencing object a to object b. But your $scope.nukes does not know about this reassignment and it still points to object a.

在这种情况下，我的解决方案是传递一个带有属性 data 的对象 a，然后只更改 data 属性而不是更改对 a 的引用>

My solution in this case is to pass a object a with property data and then only change the data property instead of changing reference to a

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