Create common.js

static/common.js

@@ -0,0 +1,18 @@
+const apiBase = '';
+
+function apiPost(path, body) {
+    return fetch(`${apiBase}${path}`, {
+        method: 'POST',
+        headers: { 'Content-Type': 'application/json' },
+        body: JSON.stringify(body)
+    }).then(res => res.json());
+}
+
+function apiGet(path) {
+    return fetch(`${apiBase}${path}`)
+        .then(res => res.json());
+}
+
+function showResult(id, data) {
+    document.getElementById(id).innerText = data.message || JSON.stringify(data, null, 2);
+}