// Display a clock, synchronized with server
// John Kellermann Friday, March 24, 2006
// Usage:
//
//
//
var req; //Global variable for XMLHttpRequest usage.
// var ustatus; //Global for status of update request. (optional)
var timerID = null;
var timerRunning = false;
var showClock;
var sync;
//Process the update request. User pressed Update button.
function getSync() {
// DO PREPARATION CODE HERE:
//showClock=document.getElementById('clock');
// ustatus=document.getElementById('upstatus'); // e.g. ***
// ustatus.innerHTML = "Updating";
//showClock.innerHTML = "Updating";
showClock=document.getElementById('clock');
if (!showClock) {
// no place to display clock on page, forget it.
return;
}
var pcDate = new Date();
var pcTime = escape(pcDate.getTime());
var pcOffset = escape(pcDate.getTimezoneOffset());
//Synchronize.
var zeRequest = "/cgi-bin/synctime2.cgi";
if (window.XMLHttpRequest) { //Non-Microsoft Browsers
req = new XMLHttpRequest();
} else if (window.ActiveXObject) { //Microsoft Browsers
req = new ActiveXObject("MSXML2.XMLHTTP.3.0");
}
req.open("POST", zeRequest, true);
req.onreadystatechange = processNewTime; //This is setting the callback function.
req.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded; charset=UTF-8');
//req.send('pcTime='+pcTime+'&pcOffset='+pcOffset);
req.send('pcTime='+pcTime);
//An asynchronous request has been sent.
// The processNewTime() function will update status when done.
}
//Process the XMLHttpRequest results (requires global variables "req" & "ustatus")
//This function is the "doneFunc" parameter of HttpRequest(reqString, doneFunc).
function processNewTime() {
// only if req shows "loaded"
if (req.readyState == 4) {
// only if "OK"
if (req.status == 200) {
// ...processing statements go here...
// ustatus.innerHTML = "Update Finished";
// alert(req.responseText); //this is a stub.
stopclock();
// ustatus.innerHTML = req.responseText;
showClock=document.getElementById('clock');
if (!showClock) {
return;
}
sync = req.responseText;
showTime(sync);
} else {
alert("Server Failure Message:\n" + req.statusText);
ustatus.innerHTML = "Update Failed";
}
}
}
function stopclock () {
if(timerRunning)
clearTimeout(timerID);
timerRunning = false;
}
function showTime (sync) {
//return;
var now = new Date();
now.setTime (now.getTime() - sync);
var hours = now.getHours();
var minutes = now.getMinutes();
var seconds = now.getSeconds();
var ampm = (hours >= 12) ? "pm" : "am";
hours = ((hours >12) ? hours -12 :hours);
hours = ((hours == 0) ? 12 :hours); // after midnight
hours = ((hours <10)? " " :"") + hours; // don't jump to left
var timeValue = "Current time: " + hours;
timeValue += ((minutes < 10) ? ":0" : ":") + minutes;
timeValue += ((seconds < 10) ? ":0" : ":") + seconds;
timeValue += ampm;
showClock.innerHTML = timeValue;
timerID = setTimeout("showTime(sync)",1000);
timerRunning = true;
}
// End -->