added update timer

r-downing · Nov 7, 2017 · 7183b65 · 7183b65
1 parent c8f9895
commit 7183b65
Showing 1 changed file with 16 additions and 7 deletions.
diff --git a/examples/basic_rest_api/data/index.htm b/examples/basic_rest_api/data/index.htm
@@ -1,6 +1,13 @@
-<h3>Current Data <span id="status"></span></h3>
-x: <span id="x"></span><br/>
-y: <span id="y"></span>
+<h3>Current Data</h3>
+x:
+<span id="x"></span>
+<br/> y:
+<span id="y"></span>
+
+<h6>Last updated
+	<span id="ut"></span> seconds ago.
+	<span id="status"></span>
+</h6>
 
 <h3>Update Data</h3>
 <form id="xform" onsubmit="return transmit(this)">
@@ -18,26 +25,28 @@ <h3>Update Data</h3>
 
 <script>
 	function g(i) { return document.getElementById(i) };
-	var xhttp;
+	var xhttp, updateTime;
 
 	function transmit(f) {
 		if (!xhttp) { //prevent simultaneous requests
 			g("status").innerHTML = "updating...";
 			xhttp = new XMLHttpRequest();
 			xhttp.open("POST", "/api");
-			xhttp.send(f?(new FormData(f)):"");
+			xhttp.send(f ? (new FormData(f)) : "");
 			xhttp.onreadystatechange = function () {
 				if (xhttp.readyState === XMLHttpRequest.DONE && xhttp.status === 200) {
 					var data = JSON.parse(xhttp.responseText);
 					g("x").innerHTML = data.x;
 					g("y").innerHTML = data.y;
 					xhttp = null;
 					g("status").innerHTML = "";
+					updateTime = 0;
 				}
 			}
 		}
 		return false; //prevent form redirect
 	}
-
-	window.onload = transmit();
+	transmit();
+	setInterval(function () { g("ut").innerHTML = ++updateTime; }, 1000);
+	setInterval(transmit, 5000); //autoupdate display every 5s
 </script>