Update Javascript Documentation “get-country-list/index”

mohsen-deriv · mohsen-deriv · commit c8af95dbbe5d · 2023-01-10T16:58:48.000+03:30
diff --git a/docs/languages/javascript/get-country-list/index.md b/docs/languages/javascript/get-country-list/index.md
@@ -17,22 +17,42 @@ You can learn more about countries [here](/docs/core-concepts/residence-list)
 
 To get countries list, please update the `open` event listener like so:
 
-```js
+```js title="index.js"
+const ping_interval = 12000; // it's in milliseconds, which equals to 120 seconds
+let interval;
+// subscribe to `open` event
 websocket.addEventListener('open', (event) => {
   console.log('websocket connection established: ', event);
   const payload = JSON.stringify({
     residence_list: 1,
   });
   websocket.send(payload);
+
+  // to Keep the connection alive
+  interval = setInterval(() => {
+    const sendMessage = JSON.stringify({ ping: 1 });
+    websocket.send(sendMessage);
+  }, ping_interval);
 });
 ```
 
 Now update the `message` event listener to render the data:
 
-```js
+```js title="index.js"
+// subscribe to `message` event
 websocket.addEventListener('message', (event) => {
   const receivedMessage = JSON.parse(event.data);
-  console.log('get countries response', receivedMessage);
+  switch (receivedMessage.msg_type) {
+    case 'residence_list':
+      console.log('list of countries', receivedMessage.residence_list);
+      break;
+    case 'ping':
+      console.log('ping/pong response: ', receivedMessage.ping);
+      break;
+    default:
+      console.log('received message: ', receivedMessage);
+      break;
+  }
 });
 ```
 
@@ -120,3 +140,54 @@ It's better if you get the list of countries before populating your form.
 :::danger
 We need detailed content about `IDV` and `ONFIDO` identity services, their differences and possibilities
 :::
+
+your final code should be:
+
+```js title="index.js"
+const app_id = 1089; // Replace with your app_id or leave as 1089 for testing.
+const websocket = new WebSocket(`wss://ws.binaryws.com/websockets/v3?app_id=${app_id}`);
+const ping_interval = 12000; // it's in milliseconds, which equals to 120 seconds
+let interval;
+
+// subscribe to `open` event
+websocket.addEventListener('open', (event) => {
+  console.log('websocket connection established: ', event);
+  const payload = JSON.stringify({
+    residence_list: 1,
+  });
+  websocket.send(payload);
+
+  // to Keep the connection alive
+  interval = setInterval(() => {
+    const sendMessage = JSON.stringify({ ping: 1 });
+    websocket.send(sendMessage);
+  }, ping_interval);
+});
+
+// subscribe to `message` event
+websocket.addEventListener('message', (event) => {
+  const receivedMessage = JSON.parse(event.data);
+  switch (receivedMessage.msg_type) {
+    case 'residence_list':
+      console.log('list of countries', receivedMessage.residence_list);
+      break;
+    case 'ping':
+      console.log('ping/pong response: ', receivedMessage.ping);
+      break;
+    default:
+      console.log('received message: ', receivedMessage);
+      break;
+  }
+});
+
+// subscribe to `close` event
+websocket.addEventListener('close', (event) => {
+  console.log('websocket connectioned closed: ', event);
+  clearInterval(interval);
+});
+
+// subscribe to `error` event
+websocket.addEventListener('error', (event) => {
+  console.log('an error happend in our websocket connection', event);
+});
+```
