$ q承诺麻烦

时间:2016-03-08 21:27:40

标签: javascript angularjs angular-promise

我正在开发一个实用程序服务,用于处理角度的SharePoint项目。我正在更新我的代码以使用异步的角度承诺。通信而不是回调函数所以请原谅我的代码在转换过程中有点乱。我已经编写了一些代码来更新单个列表项,然后我反复使用该函数来批量更新多个项目。代码正在运行,http请求正在更改我的列表中的项目,但我似乎无法在更新多个项目时回到顶部。这是我的代码:

this.UpdateListItem = function (webUrl, listName, itemId, itemProperties, success, failure) {
    if (typeof lists[listName] === 'undefined') {
        lists[listName] = [];
    }
    var deferred = $q.defer();

    var post = angular.copy(itemProperties);
    DataUtilitySvc.ConvertDatesJson(post);
    this.GetListItemById(webUrl, listName, itemId)
        .then(function (item) {
            $http({
                url: item.__metadata.uri,
                method: 'POST',
                contentType: 'application/json',
                processData: false,
                headers: {
                    "Accept": "application/json;odata=verbose",
                    "X-HTTP-Method": "MERGE",
                    "If-Match": item.__metadata.etag
                },
                data: JSON.stringify(post),
                dataType: "json",
            }).then(function SuccessCB(response) {
                var temp = [];
                temp.push(itemProperties);
                DataUtilitySvc.MergeByProperty(lists[listName], temp, 'Id');
                deferred.resolve(response);
            }, function FailureCB(response) {
                this.GetListItems(webUrl, listName);
                deferred.reject(response);
            });
        }, function (error) {
            deferred.reject(error);
        });
    return deferred.promise;
};


this.UpdateListItems = function (webUrl, listName, itemsJson, success, failure) {
    if (numItems == -1) {
        numItems = itemsJson.length;
        c = 0;
        f = 0;
    }
    var promises = [];

    itemsJson.forEach(function (itemProps) {
        var deferred = $q.defer();
        this.UpdateListItem(webUrl, listName, itemProps.Id, itemProps)
            .then(function () {
                c++;
                if (c == numItems && f == 0) {
                    numItems = -1;
                    deferred.resolve(itemsJson[listName]);
                }
            }, function (error) {
                c++; f++;
                if (c == numItems) {
                    numItems = -1;
                    deferred.reject(error);
                }
            });
        promises.push(deferred.promise);
    }, this);
    return $q.all(promises);
};

然后我的角色控制器调用服务功能。 animateAlert调用会显示引导警报,然后使用指定的文本消失。

$scope.UpdateListItem = function (webUrl, listName, itemId, itemProperties, success, failure) {
    SPListUtility.UpdateListItem(webUrl, listName, itemId, itemProperties, success, failure)

        // The following then clause works and the animations show as intended

        .then(function success(data) {
            console.log(JSON.stringify(data));
            $scope.animateAlert("myAlert", "alertText", "Operation Successful!", "success");
        }, function failure(error) {
            console.log("Error " + error.status + ": " + error.statusText);
            $scope.animateAlert("myAlert", "alertText", "Error " + error.status + ": " + error.statusText, "danger");
        });
};

$scope.UpdateListItems = function (webUrl, listName, itemsJson, success, failure) {
    SPListUtility.UpdateListItems(webUrl, listName, itemsJson, success, failure)

        // The following section is what never seems to get called. These animations never show up

        .then(function success() {
            $scope.animateAlert("myAlert", "alertText", "Items Saved", "success");
        }, function failure(error) {
            console.log("Error " + error.status + ": " + error.statusText);
            $scope.animateAlert("myAlert", "alertText", "Error " + error.status + ": " + error.statusText, "danger");
        });
};

2 个答案:

答案 0 :(得分:0)

我认为@Bergi建议我做以下事情:

this.GetListItemById = function (webUrl, listName, itemId, loading) {
    var url = webUrl + "/_vti_bin/listdata.svc/" + listName + "(" + itemId + ")";
    return $http({
        url: url,
        method: 'GET',
        processData: false,
        headers: { "Accept": "application/json;odata=verbose" },
    }).success(function (data) {
        console.log("This Executes");
        return data.d;
    }).error( function (response) {
        return response;
    });
};

这似乎有点像我想要的那样。它执行异步调用,但它始终返回包含data,status,headers,config和statusText的整个success / then对象。即使我特意说返回数据。它仍然返回整个对象。谁知道我错过了什么?

答案 1 :(得分:0)

感谢@Bergi的回复。如果请求失败,我想将响应返回给用户。这是我的控制器中的代码:

$scope.GetListItemById = function (webUrl, listName, itemId) {
    SPListUtility.GetListItemById(webUrl, listName, itemId)
        .then(function success(data) {
            console.log(JSON.stringify(data));
            $scope.animateAlert("myAlert", "alertText", "Item: " + data.Title + " loaded", "success");
        }).catch( function failure(error) {
            console.log("Error " + error.status + ": " + error.statusText);
            $scope.animateAlert("myAlert", "alertText", "Error " + error.status + ": " + error.statusText, "danger");
        });
};

现在这些主要用于实验和测试,但我希望这项服务能够在未来发挥作用。然后似乎适用于存在的项目,但问题是,如果我尝试检索一个不存在的项目并且它抛出404,那么上面列出的那个函数在它返回时仍会被调用而不是像我一样的catch打算。我可以通过手动返回和Promise.reject更改服务功能来强制它工作,但是遵循最佳实践吗?

this.GetListItemById = function (webUrl, listName, itemId, loading) {
    var url = webUrl + "/_vti_bin/listdata.svc/" + listName + "(" + itemId + ")";
    //var deferred = $q.defer();
    return $http({
        url: url,
        method: 'GET',
        processData: false,
        headers: { "Accept": "application/json;odata=verbose" },
    }).then(function SuccessCB(response) {
        //console.log(JSON.stringify(response));
        return response.data.d;
    }, function FailureCB(response) {
        return Promise.reject(response);
    });
    //return deferred.promise;
};