Angular2异步/在位置0的共享服务JSON中出现错误

Question

I'm getting an error Unexpected token < in JSON at position 0 in my shared-service to call an API. I think its because of async request as sometimes the data is available and sometimes this error shows.

The error log is point to this request.

public getStores(): void {
 this.retrieveResults().subscribe((results) => {
  this.storesChanged.next(results.Results)
 });
}

public retrieveResults(): Observable<any> {
 return this.http.get(__env.nodeRedApiUrl + __env.storeSummaryPath)
  .map(res => res.json())
}

can someone point out why this error is actually showing? I just thought i'd be async call. Can someone direct me how to deal with async/promise in Angular2.

Answer 1

This happens mostly when you return HTML instead of json as expected. So check backend to make sure json is returned.