Setting a data type for information retrieved from an Angular HTTP request - A Step-by-Step Guide

Here is the code I use to fetch data:

login() {
    const url = api + 'login';
    this.http.post(url, this.userModel)
      .subscribe(
        data => {
          localStorage.token = data.token;
          this.router.navigate(['/home']);
        },
        error => {
          alert(error.error.error);
        }
      )
  }

This will result in a JSON object like this:

{
   message: "logged In Successful!",
   token: "e4affa4633fb046333731ae6fadcb980b98636b513a0fb80721759267b4efa5c9b7845663f2b1288"
}

Although it works and saves to local storage, I keep encountering this error in my console. Why does it happen?

https://i.stack.imgur.com/58Sbe.png

Answer №1

The reason for the error is that typescript is unable to determine the type of the response object, so you must specify the type of the response object for your post request:

  loginUser() {
    const url = api + 'login';
    this.http.post<{ message: string, token: string }>(url, this.userModel)
      .subscribe(
        data => {
          localStorage.token = data.token;
          this.router.navigate(['/home']);
        },
        error => {
          alert(error.error.error);
        }
      )
  }

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