Angular 2 how to read Custom error message from backend - rest

Question

My problem with Angular 2 that was not exist in AngularJS, that I was sending the error message as a string with backend API call in case I have error, with error status 401 as example, the problem now that I can't read this message from Angular2 http response message, while I can do that from AngularJS:
I tried the following codes and nothing was helpful:
Promise:
this._http.post('/login',{email: 'email#example.com', password: '123'})
.toPromise()
.then((resp) => console.log(resp), (error) => console.log(error));
Observable:
this._http.post('/login',{email: 'email#example.com', password: '123'})
.subscribe(response =>console.log(response), (error) => console.log(error));
And from back-end I send response as a text, for OK or Unauthorized, for OK i send back String token == UUID.randomUUID().toString();, for error I send back message like String error = " Invalid credentials ";, the problem is that the console.log works and print the text for success (token in this case), but in case error, its just prints: Response with status: 200 for URL: null.
If I change code to JSON.stringify(error) I get something like this:
{"_body":{},"status":401,"ok":false,"statusText":"Unauthorized","headers":{"null":["HTTP/1.1 401 Unauthorized"],"Access-Control-Allow-Headers":["Origin"," X-Requested-With"," Content-Type"," Accept"," Referer"," User-Agent"],"Access-Control-Allow-Met
hods":["POST"," GET"," PUT"," DELETE"," OPTIONS"],"Access-Control-Allow-Origin":["*"],"Allow":["*"],"Content-Length":["36"],"Content-Type":["text/plain; charset=utf-8"],"Date":["Tue"," 23 Aug 2016 14:53:25 GMT"]},"type":2,"url":null}
As you can see the error test not even mentioned inside the Object !!
I tried to change the response for error from backend to return json like this:
{
"message": "invalid email or password"
}
I can get the result inside _body, and I can only read it like this: console.log(error._body.message) ! but i feel its something wrong this way, and I don't want to response as a json in this case.
For angularjs (angular 1), its so simple just to print the response and everything is cool, while in angular 2 its a really problem.
What the problem, and how I can solve this issue without any refactor to backend?
Edit:
I'm using Angular 2.0.0-rc.4 and same for http : `"#angular/http": "2.0.0-rc.4"

Answer 1

Mothanfar
In my case I'm working with the Asp Web Api as back end,this thing is making me crazy as well, the only solution I found is transform in a json and read the message, I know is really ugly but works for me.
Regards.
CheckError(error: any) {
let servermsg: any = JSON.parse(error._body)["ModelState"]["Login"][0];
if (servermsg) {
this.showMsg = true;
this.msg = servermsg;
}
}

Answer 2

If you are returning JSON object from the server, you may use the below code at client side:
let errMsg: ErrorMessage = err.json();
console.log(errMsg.message)
export class ErrorMessage {
message:string;
}