Question

我正在使用ui-router和ui-router extras

$scope.$on('$transitionStart', function (e, $transition$) {
    var params = {id:1};
    factory.webService(params)
        .success(function (data) {
            if (data.d == "Expired") {//Inspects the application session
                //Stops the state request and sents you to the login screen
                e.preventDefault();
                location.href = "login.html";
            }
            else if (data.d == "NotAllowed") {
                //Stops the state request and keeps you on the state you already are
                e.preventDefault();
            } else {
                //Proceed to load the requested state
            }
        })
        .error(function (data, status) {
            alert(data.Message);
        });
});

我需要在加载$ stateChangeStart之前解决成功部分，并且无法弄清楚如何做到这一点。

有没有办法实现这个目标？

修改

所以我的代码就像这样

.state('myState', {
        url: "/myState",
        templateUrl: 'views/template.html',
        controller: 'ctrlTemplate',
        viewId: 99,
        resolve: {
            fn: function ($stateParams, myFactory) {
                myFactory.checkSession({viewId:99})
                .then(function onSuccess(response) {
                    var data = response.data;
                    if (data.d == "Expired") {
                        throw "Expired";
                    }
                    else if (data.d == "NotAllowed") {
                        throw "NotAllowed";
                    } else {
                        //RETURN to chain data
                        return data;
                        //Proceed to load the requested state
                    }
                })
                .catch(function (response) {
                    //e.preventDefault();
                });
            }
        }
    })

$ http .then函数仍然在$stateChangeStart $transitionStart发生后解析，并且新状态已经加载。我可以在浏览器控制台调试器中看到它发生了

Plz帮助。

Answer 1

是的，有更优雅的方式：resolve by ui-router

示例：

$stateProvider.state('users.profile', {
  url: '/:id',
  templateUrl: 'views/users.profile.html',
  controller: 'UsersController',
  resolve: {
    user: function($stateParams, UserService) {
      return UserService.find($stateParams.id);
    },
    tasks: function(TaskService, user) {
      return user.canHaveTasks() ?
        TaskService.find(user.id) : [];
    }
  }
});

请阅读Advanced routing and resolves上的以下文章了解更多详情。

Answer 2

我需要等待$ http响应并在.success函数
上捕获它

.success方法(deprecated and now removed from AngularJS 1.6)无法拒绝承诺，但.then方法能够将成功转化为拒绝：

var promise = factory.webService(params)
    //.success(function (data) {
    .then( function onSuccess(response) {
        var data = response.data;
        if (data.d == "Expired") {
            //THROW to create a rejected promise
            throw "Expired";
            /*
            //Inspects the application session
            //Stops the state request and sents you to the login screen
            e.preventDefault();
            location.href = "login.html";
            */
        }
        else if (data.d == "NotAllowed") {
            //THROW to create a rejected promise
            throw "NotAllowed";
            /*
            //Stops the state request and keeps you on the state you already are
            e.preventDefault();
            */
        } else {
            //RETURN to chain data
            return data;
            //Proceed to load the requested state
        }
    })
    //.error(function onError(data, status) {
    .catch( function(response) {
        var data = response.data;
        var status = response.status;
        alert(data.Message);
        //THROW to chain rejection
        throw data.Message;
    });
});

通过使用return或throw语句，可以从httpPromise的.then或.catch方法解析的响应中创建新的派生承诺。 / p>

当ui-router状态的解析器功能被拒绝时，状态更改将中止。

更新

所以我的代码就是这样......

    //ERRONEOUS
    resolve: {
        fn: function ($stateParams, myFactory) {
            myFactory.checkSession({viewId:99})
            .then(function onSuccess(response) {
                var data = response.data;
                if (data.d == "Expired") {
                    throw "Expired";
                }

我无法理解为什么投掷不会触发$ stateChangeError。

解析器功能需要返回对路由器的承诺：

    resolve: {
        fn: function ($stateParams, myFactory) {
          //vvvvvv RETURN the promise
            return myFactory.checkSession({viewId:99})
            .then(function onSuccess(response) {
                var data = response.data;
                if (data.d == "Expired") {
                    throw "Expired";
                }

当函数省略return语句时，函数返回值undefined。在这种情况下，路由器认为它成功，值为undefined。

.catch方法也是错误的

    //ERRONEOUS   
          })
            .catch(function (response) {
                //e.preventDefault();
            });

当.catch方法的拒绝处理程序省略return（或throw）语句时，该函数返回值undefined。这会将转换拒绝转换为以undefined值解析的成功承诺。

      //CORRECT   
            })
            .catch(function (response) {
                //THROW to chain rejection
                throw response;
                //e.preventDefault();
            });

功能编程的经验法则是 - 总是返回。

在承诺成功和拒绝的情况下：始终return或throw。

在状态更改UI-Router之前解析promise

2 个答案:

更新