无需发出多个请求即可在控制器之间共享异步数据

问题描述

我正在尝试发出一个 $http 请求来获取我的一个 JSON 文件并在我的所有控制器中使用这些数据.

I'm trying to make a single $http request to get one of my JSON files and use the data across all my controllers.

我在 egghead.io 上看到了如何在多个控制器之间共享数据，我还阅读了这个 StackOverflow 问题:在 angular.js 中的控制器之间共享变量".

I saw on egghead.io how to share data across multiple controllers, and I've also read this StackOverflow question: "Sharing a variable between controllers in angular.js".

然而，那里的答案不使用 $http 模块.使用 $http 时，控制器没有数据可以处理，当收到响应时已经太晚了.

However, the answers there don't use the $http module. When using $http, the controllers don't have the data to work on, and by the time the response is received it's already too late.

然后我在 StackOverflow 上找到了方法 $q.defer 和这个问题:AngularJS 在控制器之间共享异步服务数据"

I then found the method $q.defer and this question on StackOverflow: "AngularJS share asynchronous service data between controllers"

发布在那里的解决方案工作正常，但它有两个问题:

The solution posted there works fine, BUT it has two issues:

1. 每个控制器都会触发$http请求来获取另一个控制器已经使用过的相同数据；并且，
2. 如果我尝试处理收到的数据，我有一个 then 函数.

1. Each controller will trigger the $http request to obtain the same data already used in another controller; and,
2. If I try to manipulate the data received I have a then function.

下面你可以看到我的代码:

Below you can see my code:

controllers.js

'use strict';

/* Controllers */

function appInstallerListCtrl($scope, Data) {
  $scope.apps = Data;
}

function appInstallerDetailCtrl($scope, $routeParams, Data) {
  $scope.appId = $routeParams.appId;
  $scope.apps = Data;
  console.log($scope.apps); // <-- then function
  console.log(Data); // <-- then function with $vv data returned but I can't access it

  for (var i in $scope.apps) // <--- no way, baby!
    console.log(i);
}

app.js

var app = angular.module('appInstaller', []);

app.factory('Data', function($http, $q) {
  var defer = $q.defer();
  $http.get('apps.json').then(function(result) {
    defer.resolve(result.data.versions.version);
  });
  return defer.promise;
});

app.config(['$routeProvider', function($routeProvider) {
  $routeProvider.
    when('/app', {templateUrl: 'partials/app-list.html',   controller: appInstallerListCtrl}).
    when('/app/:appId', {templateUrl: 'partials/app-detail.html', controller: appInstallerDetailCtrl}).
    otherwise({redirectTo: '/app'});
}]);

我想要的是，在启动应用程序时，将执行 $http 请求，并且响应将在整个应用程序的所有控制器中使用.

What I'd like to have is that when launching the app, the $http request will be performed and the response will be used throughout the app across all controllers.

谢谢

推荐答案

既然你使用的是promise，那么访问promise返回的数据就使用回调语法

Since you are using a promise, to access the data returned by promise use the callback syntax

function appInstallerDetailCtrl($scope, $routeParams, Data) {
  $scope.appId = $routeParams.appId;
   Data.then(function(returnedData) {
        $scope.apps=returnedData;
        console.log($scope.apps);
        for (var i in $scope.apps)
           console.log(i)
   });
}

确保这一点

defer.resolve(result.data.versions.version);

resolve 返回数组，以便上述代码工作.或者查看数据中的内容并调整控制器代码.

resolve returns array, for the above code to work. Or else see what is there in data and ajust the controller code.

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