use middleware

Author: zhiyuanliang-ms

examples/server.mjs

@@ -8,7 +8,8 @@ import { load } from "@azure/app-configuration-provider";
 const connectionString = process.env.APPCONFIG_CONNECTION_STRING;
 const appConfig = await load(connectionString, {
     refreshOptions: {
-        enabled: true
+        enabled: true,
+        refreshIntervalInMs: 5_000
     }
 });
 
@@ -18,26 +19,30 @@ appConfig.onRefresh(() => {
 
 import express from "express";
 
-const app = express();
+const server = express();
 const PORT = 3000;
 
-app.use(express.json());
+server.use(express.json());
 
-app.get("/", (req, res) => {
+// Use a middleware to achieve request-driven configuration refresh
+server.use((req, res, next) => {
+    // this call s not blocking, the configuration will be updated asynchronously
     appConfig.refresh();
+    next();
+});
+
+server.get("/", (req, res) => {
     res.send("Please go to /config to get the configuration.");
 });
 
-app.get("/config", (req, res) => {
-    appConfig.refresh();
+server.get("/config", (req, res) => {
     res.json(appConfig.constructConfigurationObject());
 });
 
-app.get("/config/:key", (req, res) => {
-    appConfig.refresh();
+server.get("/config/:key", (req, res) => {
     res.json(appConfig.get(req.params.key) ?? "");
 });
 
-app.listen(PORT, () => {
+server.listen(PORT, () => {
   console.log(`Server is running on http://localhost:${PORT}`);
 });