Return JSON errors for signup and handle in GUI

src/backend/src/routers/signup.js

@@ -120,7 +120,7 @@ module.exports = eggspress(['/signup'], {
     await svc_event.emit('puter.signup', event);
 
     if ( ! event.allow ) {
-        return res.status(400).send(event.error ?? 'You are not allowed to sign up.');
+        return res.status(400).send({ message: event.error ?? 'You are not allowed to sign up.', code: 'not_allowed_to_signup' });
     }
 
     // check if user is already logged in
@@ -153,19 +153,19 @@ module.exports = eggspress(['/signup'], {
     const is_user_signup_disabled = await lazy_user_signup();
 
     if ( is_temp_users_disabled && is_user_signup_disabled ) {
-        return res.status(403).send('User signup and Temporary users are disabled.');
+        return res.status(403).send({ message: 'User signup and Temporary users are disabled.', code: 'user_signup_and_temp_users_disabled' });
     }
 
     if ( !req.body.is_temp && is_user_signup_disabled ) {
-        return res.status(403).send('User signup is disabled.');
+        return res.status(403).send({ message: 'User signup is disabled.', code: 'user_signup_disabled' });
     }
 
     if ( req.body.is_temp && is_temp_users_disabled ) {
-        return res.status(403).send('Temporary users are disabled.');
+        return res.status(403).send({ message: 'Temporary users are disabled.', code: 'temp_users_disabled' });
     }
 
     if ( req.body.is_temp && event.no_temp_user ) {
-        return res.status(403).send('You must login or signup.');
+        return res.status(403).send({ message: 'You must login or signup.', code: 'must_login_or_signup' });
     }
 
     // Create temp user data

src/gui/src/initgui.js

@@ -1111,9 +1111,26 @@ window.initgui = async function (options) {
                     document.dispatchEvent(new Event('login', { bubbles: true }));
                 },
                 error: async (err) => {
-                    UIAlert({
-                        message: html_encode(err.responseText),
-                    });
+                    let err_obj = null;
+                    try {
+                        err_obj = JSON.parse(err.responseText);
+                    } catch (e) {
+                        err_obj = e;
+                    }
+                    if ( err_obj.code === 'must_login_or_signup' ) {
+                        await UIWindowSignup({
+                            reload_on_success: false,
+                            send_confirmation_code: false,
+                            window_options: {
+                                has_head: false,
+                                cover_page: window.is_embedded || window.is_fullpage_mode,
+                            },
+                        });
+                    } else {
+                        UIAlert({
+                            message: err_obj.message ?? 'There was an error creating your account. Please try again.',
+                        });
+                    }
                 },
                 complete: function () {