The most recent project page needed to display server time in real time, and if the server time was loaded through ajax every second, there would be a lot of requests.

Therefore, a combination of “javscript self-running clock” and “ajax load server time “was designed to display the server time. The “javscript self-running clock” runs automatically from an initial time, and the “ajax load server time “updates the server time to the” javscript self-running clock “every 60s.

Javscript self-running clock:

String.prototype.format = function() {
var args = arguments;
return this.replace(/{(d+)}/g, function(m, i){return args[i];});
};


String.prototype.toInt = function(defaultV) {
if (this === "" || !(/^d+$/.test(this))) return defaultV;
return parseInt(this);
};

window.scClock =
{
year : 2014,
month : 1,
day : 1,
hour : 0,
minute : 0,
second : 0,

isRunning : false,

showFunc : function(){},


init : function(y, mon, d, h, min, s){
this.year = y;
this.month = mon;
this.day = d;
this.hour = h;
this.minute = min;
this.second = s;
},


updateTime : function(time) {
var arr = time.split(/[- :]/);
if (arr.length != 6) return;

this.year = arr[0].toInt(2014);
this.month = arr[1].toInt(1);
this.day = arr[2].toInt(1);
this.hour = arr[3].toInt(0);
this.minute = arr[4].toInt(0);
this.second = arr[5].toInt(0);
},


updateTime : function(time) {
var arr = time.split(/[- :]/);
if (arr.length != 6) return;

this.year = arr[0].toInt(2014);
this.month = arr[1].toInt(1);
this.day = arr[2].toInt(1);
this.hour = arr[3].toInt(0);
this.minute = arr[4].toInt(0);
this.second = arr[5].toInt(0);
},


startup : function(func) {
if (this.isRunning) return;
this.isRunning = true;
this.showFunc = func;
window.setTimeout("scClock.addOneSec()", 1000);
},


shutdown : function() {
if (!this.isRunning) return;
this.isRunning = false;
},


getDateTime : function() {
var fmtString = "{0}-{1}-{2} {3}:{4}:{5}";
var sMonth = (this.month < 10) ? ("0" + this.month) : this.month;
var sDay = (this.day < 10) ? ("0" + this.day) : this.day;
var sHour = (this.hour < 10) ? ("0" + this.hour) : this.hour;
var sMinute = (this.minute < 10) ? ("0" + this.minute) : this.minute;
var sSecond = (this.second < 10) ? ("0" + this.second) : this.second;
return fmtString.format(this.year, sMonth, sDay, sHour, sMinute, sSecond);
},


addOneSec : function() {
this.second++;
if (this.second >= 60) {
this.second = 0;
this.minute++;
}
if (this.minute >= 60) {
this.minute = 0;
this.hour++;
}
if (this.hour >= 24) {
this.hour = 0;
this.day++;
}
switch(this.month) {
case 1:
case 3:
case 5:
case 7:
case 8:
case 10:
case 12: {
if (this.day > 31) {
this.day = 1;
this.month++;
}
break;
}
case 4:
case 6:
case 9:
case 11: {
if (this.day > 30) {
this.day = 1;
this.month++;
}
break;
}
case 2: {
if (this.isLeapYear()) {
if (this.day > 29) {
this.day = 1;
this.month++;
}
} else if (this.day > 28) {
this.day = 1;
this.month++;
}
break;
}
}
if (this.month > 12) {
this.month = 1;
this.year++;
}

this.showFunc(this.getDateTime());

if (this.isRunning)
window.setTimeout("scClock.addOneSec()", 1000);
},


isLeapYear : function() {
if (this.year % 4 == 0) {
if (this.year % 100 != 0) return true;
if (this.year % 400 == 400) return true;
}
return false;
}

};

Calling code:

function startupClock() {
if (window.scClock) {
window.scClock.startup(function(time){
$("#currTime").text(time);
});
}
}

function loadSystemTime() {
var jsonData = {
"ajaxflag": 1,
"mod": "time_mod"
};
$.getJSON(ajax_sc_url, jsonData, function(data){
if (data.code==0) {
if (window.scClock)
window.scClock.updateTime(data.time);
}
});
setTimeout("loadSystemTime()", 60000);
}

HTML display code:

<span id="currTime"></span>