Angular 2：遇到從MockBackend靜態解析符號值的錯誤

Question

我是Angular2的新手，試圖運行這個tutorial。它使用fakeBackendProvide來模擬使用MockBackend的後端調用。

邏輯的fackBackend是這樣的： export let fakeBackendProvider = {}

index.ts類有助於出口fackBackendProvider有一行： export * from './fake-backend';

app.module.ts看起來是這樣的：

providers: [ 
    AuthGuard, 
    AuthenticationService, 
    UserService, 

    //fake backend providers 
    fakeBackendProvider, 
    MockBackend, 
    BaseRequestOptions 
    ], 

我得到這個錯誤消息： ERROR in Error encountered resolving symbol values statically. Function calls are not supported. Consider replacing the function or lambda with a reference to an exported function (position 7:15 in the original .ts file), resolving symbol fakeBackendProvider in /Users/hyadav/Documents/hp-app/src/app/helpers/fake-backend.ts, resolving symbol fakeBackendProvider in /Users/hyadav/Documents/hp-app/src/app/helpers/index.ts, resolving symbol AppModule in /Users/hyadav/Documents/hp-app/src/app/app.module.ts, resolving symbol AppModule in /Users/hyadav/Documents/hp-app/src/app/app.module.ts

不知道怎麼回事。

代碼的休息，可以在這裏找到：Github

Answer 1

我有同樣的問題，用相同的教程。我所做的只是從lambda表達式創建一個新函數，然後在fakeBackendProvider中的useFactory中調用它。

export function mockBackEndFactory(backend: MockBackend, options: BaseRequestOptions, realBackend: XHRBackend) { ... } 

export let fakeBackendProvider = { 
    provide: Http, 
    deps: [MockBackend, BaseRequestOptions, XHRBackend], 
    useFactory: mockBackEndFactory 
}; 

這裏的鏈接，假backend.ts文件我修改：https://github.com/cealmees/Angular2-training/blob/master/src/app/entities/login/helpers/fake-backend.ts