在状态改变之前解决承诺 UI-Router

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，但不知道该怎么做。

有什么方法可以实现吗？

编辑

所以我有这样的代码

.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 函数在 $stateChangeStart 和 $transitionStart 发生后仍在解析，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

请帮忙。

Answer 1

是的，有更优雅的方法：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) : [];
    }
  }
});

有关详细信息，请阅读 Advanced routing and resolves 上的以下文章。

Answer 2

i need to wait for the $http response and catch it on the .success function

.success 方法无法拒绝承诺，但 .then 方法能够转换成功拒绝：

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，根据 httpPromise 的 .then 或 .catch 方法解析的响应创建一个新的派生承诺.

当 ui-router 状态的解析器函数收到拒绝的承诺时，状态更改将中止。

更新

So I have my code like this ...

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

I can't understand why the throw doesn't trigger the $stateChangeError.

解析器功能需要return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 return 的值为 undefined。在这种情况下，路由器认为它是成功的，值为 undefined.

还有.catch方法是错误的

    //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，函数 return 的值为 undefined。这将 将拒绝转换为 成功的承诺，该承诺的解析值为 undefined。

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

函数式编程的经验法则是——总是return某事。

在承诺成功和拒绝的情况下：总是 return 或 throw 某事。

在状态改变之前解决承诺 UI-Router

Resolve a promise before state changes UI-Router

angularjs

angular-ui-router

angular-ui-router-extras

更新