angular - 成功在服务中调用订阅后获取未定义(Getting Undefined after subscribe successfully called in Service)

Question

actually am new in angular and am trying to create an recipe app so here what i have created an recipes service in which there is two method ie storeRecipe() , fetchRecipe()

(实际上在角度上是一个新手，正在尝试创建一个食谱应用程序，因此在这里我创建了一个食谱服务，其中有两种方法，即storeRecipe() ， fetchRecipe())

Recipe.Service.ts here is constructor in my Recipe Service

(这里的Recipe.Service.ts是我的配方服务中的构造函数)

currentUser;
constructor(@Inject(LOCAL_STORAGE) private localstorage: StorageService, private http: HttpClient, private firstore: AngularFirestore, private authService : AuthService) { 
    this.authService.getCurrentUser().subscribe(user => {
      this.currentUser = user.uid
      console.log(this.currentUser)
    })

  }

Now here am subscribing to observable and getting currently loggedIn User and save that user in currentUser when i console currentUser am getting what i want but in fetchRecipe method am not getting currentUser but in store Recipe method am getting currentUser how to get currentUser in fetchRecipe so then i get recipe when my component Initialize

(现在，这里是订阅观察到的，让目前的loggedIn用户，并保存在用户currentUser当我安慰currentUser我得到我想要什么，但在fetchRecipe方法时没有得到currentUser但在店内配方方法正在逐渐currentUser如何让currentUser在fetchRecipe这样的话我的组件初始化时得到配方)

Store and fetch Recipe Method

(存储并获取配方方法)

  storeRecipe(data) {

    let randomId = this.firstore.createId()
    console.log(randomId)
    return this.firstore.collection('Recipes').doc(this.currentUser).set({ fid: randomId, ...data }).then(i => {
      this.recipes.push({ fid: randomId, ...data })
    })
}
fetchRecipe() {

    console.log(this.currentUser) // <-- here am getting undefined
    return this.firstore.collection('Recipes').get().subscribe(data => {
      data.docs.map(i => {
        this.recipes.push(i.data())

        this.loading.emit(false)
      })
    })
 }

  ask by Himanshu Rahi translate from so

Answer 1

If you want to call the fetchRecipe() on component initialization, you could just pass the value to the fetchRecipe() once you get the data successfully as,

(如果您要在组件初始化时调用fetchRecipe（），则可以在成功获取数据后将值传递给fetchRecipe（），如下所示：)

this.authService.getCurrentUser().subscribe(user => {
      this.currentUser = user.uid
      console.log(this.currentUser);
      fetchRecipe(this.currentUser);
})

and access

(和访问)

fetchRecipe(currentUser : any) {
  use the value here
}