angularjs – 如何取消$resource请求

我试图找出如何使用$资源的timeout属性动态取消挂起的请求。理想情况下，我想只能取消请求与某些属性(基于发送的params)，但似乎这可能是不可能的。在此期间，我只是试图取消所有待处理的请求，然后重置超时承诺允许新的请求。

问题似乎是$ resource配置只允许一个单一的静态promise的超时值。如果我正在进行单独的$ http调用，我可以做到这一点是有意义的，因为我可以只传递新的承诺超时，但是如何工作的一个$资源？我在这里设置了一个示例：http://plnkr.co/edit/PP2tqDYXh1NAOU3yqCwP?p=preview

这里是我的控制器代码：

app.controller('MainCtrl',function($scope,$timeout,$q,$resource) {
  $scope.canceller = $q.defer();
  $scope.pending = 0;
  $scope.actions = [];
  var API = $resource(
    'index.html',{},{
      get: {
        method: 'GET',timeout: $scope.canceller.promise
      }
    }
  )

  $scope.fetchData = function() {
    if ($scope.pending) {
      $scope.abortPending();
    }
    $scope.pending = 1;
    $scope.actions.push('request');
    API.get({},function() {
      $scope.actions.push('completed');
      $scope.pending = 0;
    },function() {
      $scope.actions.push('aborted');
    });
  }

  $scope.abortPending = function() {
    $scope.canceller.resolve();
    $scope.canceller = $q.defer();
  }
});

现在，当有一个挂起的请求时，取消器工作，但我似乎不能重置它 – 一旦一个请求被中止，所有未来的请求也将被中止。

我相信我错过了一些东西，因为能够取消挂起的请求似乎是大多数Web应用程序(至少我已经构建)的一个非常关键的功能。

谢谢

回答 stefchri为我工作，但我不得不进行一些修改，以便：

>启用资源ajax调用将被取消多次，而无需重新创建资源
>使资源向后兼容 – 这意味着不需要更改除资源工厂之外的任何应用程序(控制器)代码
>使代码与JSLint兼容

这是完整的服务工厂实现(你只需要放正确的模块名称)：

'use strict';

/**
 * ResourceFactory creates cancelable resources.
 * Work based on: http://stackoverflow.com/a/25448672/1677187
 * which is based on: https://developer.rackspace.com/blog/cancelling-ajax-requests-in-angularjs-applications/
 */
/* global array */
angular.module('module_name').factory('ResourceFactory',['$q','$resource',function($q,$resource) {

        function abortablePromiseWrap(promise,deferred,outstanding) {
            promise.then(function() {
                deferred.resolve.apply(deferred,arguments);
            });

            promise.catch(function() {
                deferred.reject.apply(deferred,arguments);
            });

            /**
             * Remove from the outstanding array
             * on abort when deferred is rejected
             * and/or promise is resolved/rejected.
             */
            deferred.promise.finally(function() {
                array.remove(outstanding,deferred);
            });
            outstanding.push(deferred);
        }

        function createResource(url,options,actions) {
            var resource;
            var outstanding = [];
            actions = actions || {};

            Object.keys(actions).forEach(function(action) {
                var canceller = $q.defer();
                actions[action].timeout = canceller.promise;
                actions[action].Canceller = canceller;
            });

            resource = $resource(url,actions);

            Object.keys(actions).forEach(function(action) {
                var method = resource[action];

                resource[action] = function() {
                    var deferred = $q.defer(),promise = method.apply(null,arguments).$promise;

                    abortablePromiseWrap(promise,outstanding);

                    return {
                        $promise: deferred.promise,abort: function() {
                            deferred.reject('Aborted');
                        },cancel: function() {
                            actions[action].Canceller.resolve('Call cancelled');

                            // Recreate canceler so that request can be executed again
                            var canceller = $q.defer();
                            actions[action].timeout = canceller.promise;
                            actions[action].Canceller = canceller;
                        }
                    };
                };
            });

            /**
             * Abort all the outstanding requests on
             * this $resource. Calls promise.reject() on outstanding [].
             */
            resource.abortAll = function() {
                for (var i = 0; i < outstanding.length; i++) {
                    outstanding[i].reject('Aborted all');
                }
                outstanding = [];
            };

            return resource;
        }

        return {
            createResource: function (url,actions) {
                return createResource(url,actions);
            }
        };
    }
]);

用法与stefchri示例中的相同。服务工厂：

'use strict';

angular.module('module_name').factory('YourResourceServiceName',['ResourceFactory',function(ResourceFactory) {
    return ResourceFactory.createResource('some/api/path/:id',{ id: '@id' },{
        create: {
            method: 'POST'
        },update: {
            method: 'PUT'
        }
    });
}]);

控制器中的用法(向后兼容)：

var result = YourResourceServiceName.create(data);
result.$promise.then(function success(data,responseHeaders) {
    // Successfully obtained data
},function error(httpResponse) {
    if (httpResponse.status === 0 && httpResponse.data === null) { 
        // Request has been canceled
    } else { 
        // Server error 
    }
});
result.cancel(); // Cancels XHR request

替代方法：

var result = YourResourceServiceName.create(data);
result.$promise.then(function success(data,responseHeaders) {       
    // Successfully obtained data
}).catch(function (httpResponse) {
    if (httpResponse.status === 0 && httpResponse.data === null) { 
        // Request has been canceled
    } else { 
        // Server error 
    }
});
result.cancel(); // Cancels XHR request

进一步改进：

>我不喜欢检查请求是否已取消。更好的方法是在请求被取消时附加属性httpResponse.isCanceled，并且中止类似。

angularjs – 如何取消$resource请求

猜你在找的Angularjs相关文章