router now working, implemented login and logout

Signed-off-by: Stephan Richter <s.richter@srsoftware.de>

frontend/src/App.svelte

@@ -21,6 +21,7 @@
 
 {#if translations_ready }
     {#if user.name }
+        <!-- https://github.com/notnotsamuel/svelte-tiny-router -->
         <Router>
             <Menu />
             <Route path="/" component={Home} />

frontend/src/Components/Login.svelte

@@ -1,6 +1,8 @@
 <script>
+    import { onMount } from 'svelte';
     import { t } from '../translations.svelte.js';
-    import { tryLogin } from '../user.svelte.js';
+    import { checkUser, tryLogin } from '../user.svelte.js';
+
     let credentials = { username : null, password : null }
 
     function doLogin(ev){
@@ -10,6 +12,10 @@
     function init(element){
         element.focus();
     }
+
+    onMount(async () => {
+        await checkUser();
+    });
 </script>
 <style>
     label { display: block; margin: 5px; }

frontend/src/Components/Menu.svelte

@@ -1,17 +1,13 @@
 <script>
+    import { logout, user } from '../user.svelte.js';
     import { useTinyRouter } from 'svelte-tiny-router';
     import { t } from '../translations.svelte.js';
-    import { user } from '../user.svelte.js';
 
     const router = useTinyRouter();
 
     function gotoAbout(){
         router.navigate('/about');
     }
-
-    function logout(){
-        user.name = null;
-    }
 </script>
 <nav>
     <a on:click={() => router.navigate('/')}>{t('nav.Home')}</a>

frontend/src/user.svelte.js

@@ -2,9 +2,29 @@ export const user = $state({
     name : null
 })
 
+export async function checkUser(){
+    var url = `${location.protocol}//${location.host.replace('5173','8080')}/api/user/whoami`;
+    let response = await fetch(url,{
+        credentials: 'include'
+    });
+    if (response.ok){
+        const json = await response.json();
+        for (var key of Object.keys(json)) user[key] = json[key];
+    }
+}
+
+export async function logout(){
+    var url = `${location.protocol}//${location.host.replace('5173','8080')}/api/user/logout`;
+    await fetch(url,{
+        credentials: 'include'
+    });
+    user.name = null;
+}
+
 export async function tryLogin(credentials){
     var url = `${location.protocol}//${location.host.replace('5173','8080')}/api/user/login`;
     let response = await fetch(url,{
+        credentials: 'include',
         headers: {
             'Content-Type':'application/json'
         },