如何从Angular 2中的组件迭代Observable响应对象

Question

I calling the service from Component class and getting Observable (Customers) Object as response. If i use <div *ngFor="let cust of customerDetailsItem"> {{cust.id}} </div> then i am getting the values. but if i want use that observable response in component then it showing " Undefined ".

    constructor(public service:ViewListCustomerServiceService) {
    this.service.getCustomerItemList().subscribe(lst =>this.customerDetailsItem=(lst));
console.log(this.customerDetailsItem);    //Showing Undefined.
  }

because i want " customerDetailsItem " for assign data to Json object in Component class.

Answer 1

Your object this.customerDetailsItem will be undefined until you get a response from the subscription. So what you can do is execute the code that is necessary after you receive the lst .

constructor(...) {
    this.service.getCustomerItemList()
        .subscribe(lst=>this.initialize(lst));
}

initialize(lst: any) {
   this.customerDetailsItem = lst;
   // from now on your object will be set
}