Add api.js module

public/js/api.js

@@ -0,0 +1,30 @@
+let _apiPending = 0;
+
+function _apiBar() {
+  document.getElementById('api-bar').classList.toggle('loading', _apiPending > 0);
+}
+
+export function api(method, path, body) {
+  const opts = { method, credentials: 'include', headers: { 'Content-Type': 'application/json' } };
+  if (body) opts.body = JSON.stringify(body);
+  _apiPending++; _apiBar();
+  return fetch('api/' + path, opts)
+    .then(res => res.json().then(data => {
+      if (!res.ok) { const e = new Error(data.error || 'Fehler'); e.status = res.status; throw e; }
+      return data;
+    }).catch(e => {
+      if (e.status) throw e;
+      const ne = new Error('Fehler'); ne.status = res.status; throw ne;
+    }))
+    .catch(e => {
+      if (e.status === 401 && path !== 'login') {
+        document.dispatchEvent(new CustomEvent('session-expired'));
+      }
+      throw e;
+    })
+    .finally(() => { _apiPending--; _apiBar(); });
+}
+
+export function loadGoals() {
+  return api('GET', 'goals');
+}