在 AngularJS 中取消请求

Question

我浏览了一些链接：

How to cancel an $http request in AngularJS?

Cancelling ongoing Angular $http requests when there's a new request

How to cancel a $http call from controller in Angular JS?

http://embed.plnkr.co/gkvxRj/

但在我的代码中不起作用

如何取消之前的请求？下面在我的请求服务代码中。

function PostData (url, data,cancelPrevious, auth, token, headers) {
            var deferred = $q.defer();
            token = token || window.apiToken;
            headers = headers || {};
            if (cancelPrevious && $http.pendingRequests.length > 0) {
                deferred.resolve('cancel');
                var deferred = $q.defer();
                var newPostData = data ? JSON.stringify(JSON.parse(data)) : null;
                $http({
                    method: "POST",
                    url: url,
                    headers: headers,
                    data: newPostData
                }).then(function (response) {
                    deferred.resolve(response.data);
                }),
                    function (data) {
                        deferred.resolve(data);
                    };

                return deferred.promise;
            } else {
                var newPostData = data ? JSON.stringify(JSON.parse(data)) : null;
                $http({
                    method: "POST",
                    url: url,
                    headers: headers,
                    data: newPostData
                }).then(function (response) {
                    deferred.resolve(response.data);
                }),
                    function (data) {
                        deferred.resolve(data);
                    };

                return deferred.promise;
            }
            
        };

Using - 
Service.PostData(config.apiBaseUrl + "Monitoring/GetAllSpotLines", JSON.stringify(postData), true)

如果 $http.pendingRequests 数组中有任何请求未决，我将使用“cancelPrevious”标志取消请求。

我已经清楚地检查过它正在进入该条件，但 deferred.resolve('cancel') 不起作用

Answer 1

您可以将较早的 Promise 对象存储在另一个变量中，当您发现待处理的请求大于 0 时，您可以解决待处理的 Promise。查看更新的代码：

var pendingDeferred;
function PostData (url, data,cancelPrevious, auth, token, headers) {
            var deferred = $q.defer();
            token = token || window.apiToken;
            headers = headers || {};
            if (cancelPrevious && $http.pendingRequests.length > 0 && pendingDeferred) {
                
                pendingDeferred.resolve('cancel');                
                pendingDeferred = deferred;
                var newPostData = data ? JSON.stringify(JSON.parse(data)) : null;
                $http({
                    method: "POST",
                    url: url,
                    headers: headers,
                    data: newPostData
                }).then(function (response) {
                    deferred.resolve(response.data);
                }),
                    function (data) {
                        deferred.resolve(data);
                    };

                return deferred.promise;
            } else {
                pendingDeferred = deferred;
                var newPostData = data ? JSON.stringify(JSON.parse(data)) : null;
                $http({
                    method: "POST",
                    url: url,
                    headers: headers,
                    data: newPostData
                }).then(function (response) {
                    deferred.resolve(response.data);
                }),
                    function (data) {
                        deferred.resolve(data);
                    };

                return deferred.promise;
            }
            
        };

我已将较早的承诺存储在“pendingDeferred”变量中，下次如果找到待处理的请求，则解决待处理的承诺。