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我无法将工厂中 Angular 承诺的数据返回到控制器。在这个例子中，

http://jsfiddle.net/c3xjE/

update: function (staffList) {
    // get local last updated timestamp
    var lastUpdatedLocal = "";
    var lastUpdatedRemote = "";
    for (i=0; i < staffList.length; i++) {
        // get largest (most recent) timestamp
        if(staffList[i].entry_date > lastUpdatedLocal) {
            lastUpdatedLocal = staffList[i].entry_date;
        }
    }

// get remote last updated timestamp
var promise = $http.get('REMOTE_API_CALL')
    .success(function(data, status, header, config) {
        return lastUpdatedRemote = data[0].entry_date;
    }).then(function(response) {
        return response.data[0].entry_date;
        });
    console.log(promise);
}

我想过滤本地数据以获取本地时间戳，将其与远程时间戳进行比较，如果本地时间戳小于远程时间戳，则指示控制器重新下载所有数据。

我正在过滤本地数据并获得预期的结果。我似乎陷入困境的地方是承诺。我可以在 .success 或 .then 方法中注销过滤后的远程数据，但从 Promise 中返回值的运气并不好。我知道这里的变量范围可能存在问题。

另外，我最好是从我的工厂返回一个布尔值到我的控制器（我应该更新吗？真/假）或者可能是一个带有本地和远程时间戳数据的小 obj，然后让控制器决定从那里做什么？

提前致谢。

4

1 回答 1

2

这是我如何实现这一点的最佳示例。我假设了一些关于你的控制器和工厂的东西。请注意，您需要将 $q 注入您的工厂以使用延迟。这就是我在我的应用程序中的做法。

http://jsfiddle.net/JimTheDev/2zLEp/

/*
  NOTE: make sure to inject $q into your factory before
  this. For the purposes of my example, let's assume your
  factory looks like this:
*/
app.factory('mySweetFactory', ['$q', function($q) {
    return {

        // You probably have a bunch of other methods like
        // this one in your factory.
        myothermethod: function(argument1, argument2) { 
            /* some code here */
        },

        update: function (staffList) {

            // Create a new deferred object
            var deferred = $q.defer();

            // get local last updated timestamp
            var lastUpdatedLocal = "";
            for (i=0; i < staffList.length; i++) {
                // get largest (most recent) timestamp
                if(staffList[i].entry_date > lastUpdatedLocal) {
                    lastUpdatedLocal = staffList[i].entry_date;
                }
            }

            // Make a call to the remote api
            $http.get('REMOTE_API_CALL').then(function(response) {

                // Get the remote last updated
                // time from the response
                var lastUpdatedRemote = response.data[0].entry_date;

                // Check if local or remote is larger
                // You probably need to modify this 
                // depending on your datetime formatting. 
                // I am assuming an epoch string.
                if(lastUpdatedRemote > lastUpdatedLocal)
                {
                    // Resolve the deferred and return
                    // the data so that the controller can
                    // use it to update the view
                    deferred.resolve(response.data);
                } else {
                    // Since we don't need to do anything,
                    // reject the deferred
                    deferred.reject();
            });

            // Return the promise from the deferred object
            // immediately. We will eventually either 
            // resolve or reject it, but at the start, it
            // will be in a pending state.
            return deferred.promise;
        }
    };
}]);

app.controller('mySweetController', ['mySweetFactory', function(mySweetFactory){
    $scope.doUpdate = function() {
        mySweetFactory.update($scope.staffList).then(function(newStaffList) {
            // Promise was resolved. List needs updating!
            $scope.staffList = newStaffList;
        }, function(){
            // Promise was rejected. No update needed!
        });
    };
}]);
于 2014-07-11T17:11:12.503 回答