AngularJS在路由更改时中止所有未决的$ http请求

Z时代
2024-01-10
分类：问答

请先检查代码

app.js

var app = angular.module('Nimbus', ['ngRoute']);

route.js

app.config(function($routeProvider) {
    $routeProvider
    .when('/login', {
        controller: 'LoginController',
        templateUrl: 'templates/pages/login.html',
        title: 'Login'
    })
    .when('/home', {
        controller: 'HomeController',
        templateUrl: 'templates/pages/home.html',
        title: 'Dashboard'
    })
    .when('/stats', {
        controller: 'StatsController',
        templateUrl: 'templates/pages/stats.html',
        title: 'Stats'
    })
}).run( function($q, $rootScope, $location, $route, Auth) {
    $rootScope.$on( "$routeChangeStart", function(event, next, current) {
        console.log("Started");
        /* this line not working */
        var canceler = $q.defer();
        canceler.resolve();
    });
    $rootScope.$on("$routeChangeSuccess", function(currentRoute, previousRoute){
        $rootScope.title = ($route.current.title) ? $route.current.title : 'Welcome';
    });
 })

home-controller.js

app.controller('HomeController',
    function HomeController($scope, API) {
        API.all(function(response){
            console.log(response);
        })
    }
)

stats-controller.js

app.controller('StatsController',
    function StatsController($scope, API) {
        API.all(function(response){
            console.log(response);
        })
    }
)

api.js

app.factory('API', ['$q','$http', function($q, $http) {    
    return {
        all: function(callback) {
            var canceler = $q.defer();
            var apiurl = 'some_url'
            $http.get(apiurl,{timeout: canceler.promise}).success(callback);
        }
    }
}]);

当我从家搬到stats时，API再次发送http请求，我有很多这样的http调用，我只粘贴了几行代码。

我需要做的是取消在routechangestart或成功时中止所有未决的http请求的操作

或任何其他方式来实现相同？

回答：

为此，我整理了一些概念代码。可能需要进行调整以满足您的需求。有一种pendingRequests服务具有用于添加，获取和取消请求的API，该服务httpService可以包装$http并确保跟踪所有请求。

通过利用$httpconfig对象（docs），我们可以获得一种取消待处理请求的方法。

我做了一个plnkr，但是您将需要快速手指才能看到请求被取消，因为我发现的测试站点通常会在半秒钟内做出响应，但是您会在devtools网络标签中看到请求确实被取消了。就您而言，您显然会触发cancelAll()来自中的适当事件的调用$routeProvider。

控制器就在那里演示该概念。

演示

angular.module('app', [])
// This service keeps track of pending requests
.service('pendingRequests', function() {
  var pending = [];
  this.get = function() {
    return pending;
  };
  this.add = function(request) {
    pending.push(request);
  };
  this.remove = function(request) {
    pending = _.filter(pending, function(p) {
      return p.url !== request;
    });
  };
  this.cancelAll = function() {
    angular.forEach(pending, function(p) {
      p.canceller.resolve();
    });
    pending.length = 0;
  };
})
// This service wraps $http to make sure pending requests are tracked 
.service('httpService', ['$http', '$q', 'pendingRequests', function($http, $q, pendingRequests) {
  this.get = function(url) {
    var canceller = $q.defer();
    pendingRequests.add({
      url: url,
      canceller: canceller
    });
    //Request gets cancelled if the timeout-promise is resolved
    var requestPromise = $http.get(url, { timeout: canceller.promise });
    //Once a request has failed or succeeded, remove it from the pending list
    requestPromise.finally(function() {
      pendingRequests.remove(url);
    });
    return requestPromise;
  }
}])
// The controller just helps generate requests and keep a visual track of pending ones
.controller('AppCtrl', ['$scope', 'httpService', 'pendingRequests', function($scope, httpService, pendingRequests) {
  $scope.requests = [];
  $scope.$watch(function() {
    return pendingRequests.get();
  }, function(pending) {
    $scope.requests = pending;
  })
  var counter = 1;
  $scope.addRequests = function() {
    for (var i = 0, l = 9; i < l; i++) {
      httpService.get('https://public.opencpu.org/ocpu/library/?foo=' + counter++);  
    }
  };
  $scope.cancelAll = function() {
    pendingRequests.cancelAll();
  }
}]);