Question

道歉，如果这是显而易见的我有点像Angular \ Javascript noob。我有以下服务：

if let objects = objects {
    var indexPaths = [NSIndexPath]
    for object in objects {
        println("The value of object.objectId is ( object.objectId)")
        self.funlists.append("\(object.objectId)")
        indexPaths.append(NSIndexPath(row: self.funlists.count - 1, section: 0))
    }
    self.tableView.insertRowsAtIndexPaths(indexPaths, rowAnimation: .Default)
}

在this.setCurrentClient函数中，我通过$ http调用后端，并在异步成功返回时通过变量getCurrentClient调用get函数。我最初试图直接调用get（）或this.get（）并且都没有工作。 .success回调函数中的上下文似乎是全局窗口上下文而不是服务上下文。上面的解决方案对我来说似乎有些混乱。有没有更好的方法来获取服务上下文并调用get（）而不是使用方法设置变量（var getCurrentClient = this.get（））然后调用它（getCurrentClient.then（））？ javascript \ angular scope和contexts有点迷失......

Answer 1

我相信你不需要使用＆＃34;这个＆＃34;在您的服务中，您可以将您的函数声明为function get() { ...，然后在setCurrentClient的回调中调用：

var getCurrentClient = get();

但是，如果你真的需要＆＃34;这个＆＃34;，常见的模式是使用var self = this;或类似的东西 - 请参阅this discussion。

（另外，我还建议您将函数和变量重命名为var clientPromise = getCurrentClient();以提高可读性。）

Answer 2

我想说在这种情况下使用angular factory。

MyApp.factory('ClientService', function ClientFactory($http, $q, SharedData) {

    function get() {
        var deferred = $q.defer();
        $http.get("/api/Client/")
            .success(function(data, status) {

                deferred.resolve(data);
            })
            .error(function(data, status) {
                deferred.reject(data);
            });

        return deferred.promise;
    };

    function setCurrentClient(clientToSelect) {
        var deferred = $q.defer();
        var getCurrentClient = get();

        $http({ method: "POST", url: "/api/Client", data: clientToSelect })
            .success(function (data, status) {

                //Get the full selected client and all its properties rather than the list version
                getCurrentClient.then(
                     function (client) {
                         setCurrentClient(client);
                         setCurrentPeriod(client);
                     },
                     function (data) {
                         //uho something broke.
                     });

                deferred.resolve(data);
            })
            .error(function (data, status) {
                deferred.reject(data);
            });

        return deferred.promise;
    }

    .....
    // Expose the service methods
    return {
        get: get,
        setCurrentClient: setCurrentClient
        ...... (Expose what all methods you wanted to expose)
    };
});

Answer 3

以下是我将如何使用服务的方式..当你试图在http请求中调用this.get然后这个将在Window范围内查找get方法，如果你打印这个在控制台中你可以看到没有get方法的关键字。此始终引用您正在使用的对象此

    MyApp.service('ClientService', function ($http, $q, SharedData) {

                    var get = function () {
                        var deferred = $q.defer();
                        $http.get("/api/Client/")
                            .success(function (data, status) {

                                deferred.resolve(data);
                            })
                            .error(function (data, status) {
                                deferred.reject(data);
                            });

                        return deferred.promise;
                    };

                    var setCurrentClient = function (clientToSelect) {
                        var deferred = $q.defer();

                        $http({
                                method: "POST",
                                url: "/api/Client",
                                data: clientToSelect
                            })
                            .success(function (data, status) {

                                //Get the full selected client and all its properties rather than the list version
                                get().then(
                                    function (client) {
                                        setCurrentClient(client);
                                        setCurrentPeriod(client);
                                    },
                                    function (data) {
                                        //uho something broke.
                                    });

                                deferred.resolve(data);
                            })
                            .error(function (data, status) {
                                deferred.reject(data);
                            });

                        return deferred.promise;
                    }
                    this.get = get;
                    this.setCurrentClient = setCurrentClient;
                });)
            .error(function (data, status) {
                deferred.reject(data);
            });

        return deferred.promise;
    }
    this.get = get;
    this.setCurrentClient = setCurrentClient;
})

Javascript \ Angular函数范围混乱

3 个答案: