Add express example

examples/package.json

@@ -2,6 +2,7 @@
   "dependencies": {
     "@azure/app-configuration-provider": "latest",
     "@azure/identity": "^4.1.0",
-    "dotenv": "^16.3.1"
+    "dotenv": "^16.3.1",
+    "express": "^4.21.2"
   }
 }

examples/refresh.mjs

@@ -26,20 +26,18 @@ const settings = await load(connectionString, {
     refreshOptions: {
         enabled: true,
         watchedSettings: [{ key: "app.settings.sentinel" }],
-        refreshIntervalInMs: 10 * 1000 // Default value is 30 seconds, shorted for this sample
+        refreshIntervalInMs: 10_000 // Default value is 30 seconds, shorted for this sample
     }
 });
 
 console.log("Using Azure portal or CLI, update the `app.settings.message` value, and then update the `app.settings.sentinel` value in your App Configuration store.")
 
 // eslint-disable-next-line no-constant-condition
 while (true) {
-    // Refreshing the configuration setting
-    await settings.refresh();
-
     // Current value of message
     console.log(settings.get("message"));
-
-    // Waiting before the next refresh
-    await sleepInMs(5000);
+    // Refreshing the configuration setting asynchronously
+    settings.refresh();
+    // wait for 5 seconds
+    await sleepInMs(5_000);
 }

examples/server.mjs

@@ -0,0 +1,51 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT license.
+
+import * as dotenv from "dotenv";
+dotenv.config()
+
+import { load } from "@azure/app-configuration-provider";
+import { DefaultAzureCredential } from "@azure/identity";
+const endpoint = process.env.APPCONFIG_ENDPOINT;
+const credential = new DefaultAzureCredential();
+const appConfig = await load(endpoint, credential, {
+    refreshOptions: {
+        enabled: true,
+        refreshIntervalInMs: 5_000
+    }
+});
+
+appConfig.onRefresh(() => {
+    console.log("Configuration has been refreshed.");
+});
+
+import express from "express";
+
+const server = express();
+const PORT = 3000;
+
+server.use(express.json());
+
+// Use a middleware to achieve request-driven configuration refresh
+// For more information, please go to dynamic refresh tutorial: https://learn.microsoft.com/azure/azure-app-configuration/enable-dynamic-configuration-javascript
+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.");
+});
+
+server.get("/config", (req, res) => {
+    res.json(appConfig.constructConfigurationObject());
+});
+
+server.get("/config/:key", (req, res) => {
+    res.json(appConfig.get(req.params.key) ?? "");
+});
+
+server.listen(PORT, () => {
+  console.log(`Server is running on http://localhost:${PORT}`);
+});

src/common/disposable.ts

@@ -15,4 +15,4 @@ export class Disposable {
         }
         this.#disposed = true;
     }
-}
+}