When utilizing Angular TypeScript, I have implemented the following approach to send a POST request. This request requires a string parameter and returns a string as the response.
sendPostRequest(postData: string): Observable<string> {
let header: HttpHeaders = new HttpHeaders();
header = header.set("Content-Type", "application/x-www-form-urlencoded");
return this.http.post<string>("http://myurl.com", "data=" + postData, {headers: header});
}
To trigger the request and handle the response, I use the following method:
this.sendPostRequest("myData").subscribe(response => {
console.log(response);
});
Upon checking the browser console, an error of HTTPErrorResponse arises with the message:
SyntaxError: Unexpected token in JSON at position 0 at JSON.parse (<anonymous>)The issue lies in the fact that the client attempts to parse the response string, even though it is not intended for JSON parsing. The server processes the request flawlessly when checked through the network tab or Postman.
Further debugging by modifying http.post() with
.pipe(response => { response.subscribe(data => console.log(data)); return response; });HTTPErrorMessage, which can be avoided by removing data => console.log(data)); from the line.
It appears that the problem does not stem from the request itself, but rather the HttpClient automatically trying to interpret the non-JSON response. Hence, instead of a typical error, a HTTPErrorMessage is triggered despite the issue originating on the client side.
This leads me to ponder: What oversight am I making? Although my usage of Observables aligns with past practices, online inquiries mostly relate to unsubscribed Observables.
To elucidate: No JSON handling should occur during this communication. Nevertheless, the client erroneously attempts to parse the plain text response.