ping timer fro websocket example

Author: doom369

docs/websocket/websocket.js.html

@@ -10,7 +10,7 @@
 <form onsubmit="return false;">
     Command : <input type="text" id="command" value="login 7038b715824d45269a3662c9648ffb9f" style="width:500px;"/><br>
     <input type="button" value="Send"
-           onclick="send()" />
+           onclick="send(command.value)" />
 
     <h3>Output</h3>
     <textarea id="output" style="width:500px;height:300px;"></textarea>
@@ -21,6 +21,7 @@ <h3>Output</h3>
 <script src="Command.js"></script>
 
 <script type="text/javascript">
+    const PING_INTERVAL_MILLIS = 5000;
     var isRunning = false;
 
     var command = document.getElementById('command');
@@ -36,6 +37,7 @@ <h3>Output</h3>
         socket.binaryType = 'arraybuffer';
         socket.onmessage = function(event) {
             if (event.data instanceof ArrayBuffer) {
+                console.log(">>>", event.data);
                 output.value += "Receive : " +  messageToDebugString(event.data) + "\r\n";
             } else {
                 output.value = "unexpected type : " + event.data + "\r\n";
@@ -56,6 +58,10 @@ <h3>Output</h3>
         alert("Your browser does not support Web Socket.");
     }
 
+    window.setInterval(function() {
+        send("ping");
+    }, PING_INTERVAL_MILLIS);
+
     function messageToDebugString(bufArray) {
         var dataview = new DataView(bufArray);
         var cmdString = getStringByCommandCode(dataview.getInt8(0));
@@ -65,15 +71,15 @@ <h3>Output</h3>
         return "Command : " + cmdString + ", msgId : " + msgId + ", responseCode : " + responseCode;
     }
 
-    function send() {
+    function send(data) {
         if (!window.WebSocket || !isRunning) {
             return;
         }
 
         if (socket.readyState == WebSocket.OPEN) {
-            var commandAndBody = command.value.split(" ");
+            var commandAndBody = data.split(" ");
             var message = createMessage(commandAndBody);
-            output.value += 'sending : ' + command.value + '\r\n';
+            output.value += 'sending : ' + data + '\r\n';
             socket.send(message);
         } else {
             alert("The socket is not open.");