How Do I Redirect Users After Login Using JavaScript Fetch API?

How to redirect the user to another page after login using JavaScript Fetch API?

Problem

Using the JavaScript code below, the authentication token is first obtained using the firebase.auth() method. A POST request is then made to the FastAPI backend. If the token is valid, a redirect response is returned. However, the user is not actually redirected, and the original page remains loaded.

<code class="javascript">function loginGoogle() {
  var provider = new firebase.auth.GoogleAuthProvider();
  firebase.auth()
    .signInWithPopup(provider)
    .then((result) => {
      // ...
    })
    .catch((error) => {
      // Handle Errors here.
      // ...
    });

  firebase.auth().currentUser.getIdToken(true).then((idToken) => {
    // ...
    const headers = new Headers({
      'x-auth-token': idToken
    });
    const request = new Request('http://localhost:8000/login', {
      method: 'POST',
      headers: headers
    });
    fetch(request)
      .then(response => response.json())
      .then(data => console.log(data))
      .catch(error => console.error(error));
  });
}</code>

Solution: Option 1 - Returning RedirectResponse

By default, the fetch() method in JavaScript sets the redirect mode to follow, meaning that the user will not be redirected to a new page but instead the redirect response will be handled automatically behind the scenes. If you want to manually handle the redirect, you can set the redirect mode to manual and then use the Response.redirected and Response.url properties to obtain the redirect URL and redirect the user yourself to that URL using window.location.href or window.location.replace().

Solution: Option 2 - Returning JSON response containing the redirect URL

Instead of returning a RedirectResponse from the server, you can return a normal JSON response with the URL included in the JSON object. On the client side, check if the JSON object returned from the server includes the url key, and if so, retrieve its value and redirect the user to that URL using window.location.href or window.location.replace().

Solution: Option 3 - Using HTML

in the frontend

If using a fetch() request is not a requirement for your project, consider using a normal HTML and have the user click on a submit button to send the POST request to the server. Using a RedirectResponse on the server side would result in the user being automatically redirected to the target URL when the form is submitted.

The above is the detailed content of How Do I Redirect Users After Login Using JavaScript Fetch API?. For more information, please follow other related articles on the PHP Chinese website!