finished location tree

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

frontend/src/routes/stock/Locations.svelte

@@ -1,9 +1,25 @@
 <script>
-    import { t } from '../../translations.svelte';
+    import { api } from '../../urls.svelte';
+    import { error, yikes } from '../../warn.svelte';
+    import { t }   from '../../translations.svelte';
 
     let { locations } = $props();
 
-    console.log(locations);
+    async function toggleChildren(ev, location){
+        ev.preventDefault();
+        ev.stopPropagation();
+        if (location.locations) {
+            delete location.locations;
+        } else {
+            const url = api(`stock/locations/below/${location.id}`);
+            const res = await fetch(url,{credentials:'include'});
+            if (res.ok){
+                yikes();
+                location.locations = await res.json();
+            } else error(res);
+        }
+        return false;
+    }
 </script>
 
 <ul>
@@ -13,7 +29,7 @@
         </a>
     </li>
     {#each locations as location}
-    <li>
+    <li onclick={e => toggleChildren(e, location)} class={location.locations?'expanded':'collapsed'}>
         {location.name}
         {#if location.locations}
         <svelte:self locations={location.locations} />