Develop Reference

Javascript pausing timer woes... Can't calculate it

I've built a series of timers that are designed to be started, paused and resumed on cue. Numbers update dynamically on my page when the timer ticks up. The issue I'm having is figuring out how to get the timer to start from where it left off before I paused it. I can get it to restart from scratch, but I unsure how to take the paused Date.now() value, and work it into the formula to display the correct value. It will be something stupid that I just cant figure out.
function ticking2(num) {
//IF TIMER IS PAUSED CANCEL THE ANIMATION FRAME
if (timerObjArray[num].paused == true) {
timerObjArray[num].restartTime = Date.now();
cancelAnimationFrame(id);
} else if (timerObjArray[num].paused == false) {
timerObjArray[num].initialTime = Date.now()
if (timerObjArray[num].restartTime != 0) {
//THIS IS THE LINE WHERE I AM HAVING TROUBLE
timerObjArray[num].milli = ((timerObjArray[num].initialTime - timerObjArray[num].initialDate) - (timerObjArray[num].initialTime - timerObjArray[num].restartTime)) / 1000;
} else {
timerObjArray[num].milli = ((timerObjArray[num].initialTime - timerObjArray[num].initialDate ) / 1000);
}
//THIS FUNCTION TAKES THE MS VALUE AND CONVERTS IT TO HH:MM:SS
convert(num, timerObjArray[num].milli * 1000);
id = requestAnimationFrame(function() {
ticking2(num);
});
}
}
Thanks for the help.

I don't have enough information so, I made a simple implementation. You can look at this to help determine what you're missing. You're welcome to use it.
Timer fiddle
Utility:
var timer = (function() {
let _timers = {};
let pub = {
start : function(id) {
if(!_timers[id]) _timers[id] = {on:true, intervals:[{start:new Date()}] };
else if(_timers[id].on) throw 'timer is already started: ' + id;
else {
_timers[id].on = true;
_timers[id].intervals.push({start:new Date()});
}
},
stop : function(id) {
if(!_timers[id]) throw 'timer does not exist, cannot be stopped: ' + id;
else if(!_timers[id].on) throw 'timer is already stopped: ' + id;
else {
_timers[id].on = false;
let interval = _timers[id].intervals[_timers[id].intervals.length -1];
interval.stop = new Date();
interval.total = interval.stop - interval.start;
}
},
read : function(id) {
if(!_timers[id]) throw 'timer does not exist, cannot be read: ' + id;
let total = 0;
for(let i=0; i<_timers[id].intervals.length; i++) {
if(_timers[id].intervals[i].total) total += _timers[id].intervals[i].total;
else total += (new Date()) - _timers[id].intervals[i].start;
}
return { intervals:_timers[id].intervals, total: total };
},
delete: function(id) {
if(!_timers[id]) throw 'timer does not exist, cannot be deleted: ' + id;
delete _timers[id];
}
};
return pub;
})();
Example usage:
$('.start').on('click', function(){
timer.start(123);
});
$('.stop').on('click', function(){
timer.stop(123);
});
$('.clear').on('click', function(){
timer.delete(123);
$('input').val('');
});
setInterval(function(){
let result = null;
try//obviously not a great pattern
{
result = timer.read(123);
} catch(ex){}
if(result) {
$('input').val(result.total);
}
}, 35);

async and set timeout

I am having some problem using the settimeout() in my function. I am new to async. No matter how much I try I just can't make the timeout work. My code works perfect so that is not the problem. I need the request to execute every 10 seconds. Thanks for the help.
function getContent() {
function getPelicula(pelicula, donePelicula) {
var peli = pelicula.title;
//request id
request({
url: "http://api.themoviedb.org/3/search/movie?query=" + peli + "&api_key=3e2709c4c051b07326f1080b90e283b4&language=en=ES&page=1&include_adult=false",
method: "GET",
json: true,
}, function(error, res, body) {
if (error) {
console.error('Error getPelicula: ', error);
return;
}
var control = body.results.length;
if (control > 0) {
var year_base = pelicula.launch_year;
var id = body.results[0].id;
var year = body.results[0].release_date;
var d = new Date(year);
var year_solo = d.getFullYear();
if (year_base == year_solo) {
pelicula.id = id;
pelicula.year_pagina = year_solo;
}
} else {
pelicula.id = null;
pelicula.year_pagina = null;
}
donePelicula();
});
}
}

To do something in a loop, use setInterval.
UPD:
In general, there're two ways of executing some code in loop
1 setTimeout :
var someTimer = setTimeout(function sayHello(){
console.log("hello!");
someTimer = setTimeout(sayHello, 2000);
}, 2000);
Notice that someTimer variable is needed to stop the looping process if you need: clearTimeout(someTimer)
2 setInterval:
var someIntervalTimer = setInterval(function(){
console.log("I'm triggered by setInterval function!");
}, 2000);
Invoke clearInterval(someIntervalTimer) to stop the looping
Both functions are treated as properties of the global Window variable. By default, the following code works:
var window = this;
console.log("type of setTimeout: " + typeof window.setTimeout);
console.log("type of setInterval: " + typeof window.setInterval);

Try putting it in another function so:
domore(pelicula,donePelicula);
function domore(pelicula,donePelicula) {
// 1 second
var timeout = 1000;
for (var i = 1; i < pelicula.length; i++) {
createData(pelicula[i],donePelicula,timeout);
timeout = timeout + 800;
}
}
function createData(peli,donePelicula,timeout) {
setTimeout(function() { getData(peli,donePelicula); }, timeout);
}
function getData(peli,donePelicula) {
var txtFile = new XMLHttpRequest();
txtFile.open("GET", "http://api.themoviedb.org/3/search/movie?query=" + peli + "&api_key=3e2709c4c051b07326f1080b90e283b4&language=en=ES&page=1&include_adult=false", true);
txtFile.onreadystatechange = function() {
if (txtFile.readyState === 4) { // Makes sure the document is ready to parse.
if (txtFile.status === 200) { // Makes sure it's found the file.
allText = txtFile.responseText;
domore(allText,donePelicula);
}
}
}
txtFile.send(null);
}

How to delay a JavaScript JSON stream for one minute?

I am ask to write a java script program that retrieve an api JSON record from and address and through websocket every single minute. The stream continues after 60 seconds. I am expected to return the respective stream retrieve and the stream from the previous retrieve . Below is my code
var obj=
{
seconds : 60,
priv : 0,
prevTick : '' ,
data : ''
}
function countTime()
{
obj.seconds --;
obj.priv ++;
var msg ;
if(obj.priv > 1)
{
obj.priv = 0;
obj.msg = null;
}
if(prop.seconds < 0)
{
msg = sock.open();
obj.msg = obj.msg + ", New Tick : " + msg.msg ;
setTimeout(countTime, 1000);
obj.seconds = 60;
}
}
var sock= new WebSocket('link');
sock.onopen = function(evt) {
ws.send(JSON.stringify({ticks:'string'}));
};
sock.onmessage = function(msg) {
var data = JSON.parse(msg.data);
return 'record update: %o'+ data ;
};
Please what is wrong with my code above ? It does not delay at all. The stream continues irrespective.

How about encapsulating the buffering behavior into a class?
function SocketBuffer(socket, delay, ontick) {
var messages = [], tickInterval;
socket.onmessage = function(msg) {
messages.push( JSON.parse(msg.data) );
};
function tick() {
if (typeof ontick !== "function") return;
ontick( messages.splice(0) );
}
this.pause = function () {
tickInterval = clearInterval(tickInterval);
};
this.run = function () {
if (tickInterval) return;
tickInterval = setInterval(tick, delay * 1000);
tick();
};
this.run();
}
Note that .splice(0) returns all elements from the array and empties the array in the same step.
Usage:
var link = new WebSocket('link');
link.onopen = function (evt) {
this.send( JSON.stringify({ticks:'string'}) );
};
var linkBuf = new SocketBuffer(link, 60, function (newMessages) {
console.log(newMessages);
});
// if needed, you can:
linkBuf.pause();
linkBuf.run();

Try this:
function countTime() {
var interval = 1000; // How long do you have to wait for next round
// setInterval will create infinite loop if it is not asked to terminate with clearInterval
var looper = setInterval(function () {
// Your code here
// Terminate the loop if required
clearInterval(looper);
}, interval);
}

If you use setTimeout() you don't need to count the seconds manually. Furthermore, if you need to perform the task periodically, you'd better use setInterval() as #RyanB said. setTimeout() is useful for tasks that need to be performed only once. You're also using prop.seconds but prop doesn't seem to be defined. Finally, you need to call countTime() somewhere or it will never be executed.
This might work better:
var obj=
{
seconds : 60,
priv : 0,
prevTick : '' ,
data : ''
}
function countTime()
{
obj.seconds --;
obj.priv ++; //I don't understand this, it will always be set to zero 3 lines below
var msg ;
if(obj.priv > 1)
{
obj.priv = 0;
obj.msg = null;
}
msg = sock.open();
obj.msg = obj.msg + ", New Tick : " + msg.msg;
obj.seconds = 60;
//Maybe you should do sock.close() here
}
var sock= new WebSocket('link');
sock.onopen = function(evt) {
ws.send(JSON.stringify({ticks:'string'}));
};
sock.onmessage = function(msg) {
var data = JSON.parse(msg.data);
return 'record update: %o'+ data ;
};
var interval = setInterval(countTime, 1000);
EDIT: finally, when you're done, just do
clearInterval(interval);
to stop the execution.

Starting Javascript intervals nonsynchronously and stop each after three runs

I have a function for letting blink a OpenLayer marker three times. The simplified version which only shows console messages:
function blink_three_times(layername){
var x = 0;
setTimeout(function() {
blink_in = setInterval(function() {
x = x+1;
if ( x === 3) {clearInterval(blink_in)};
console.log(layername + ' is visible');
}, 500);
}, 250);
blink_out = setInterval(function() {
if (x === 2) {clearInterval(blink_out)};
console.log(layername + ' is invisible');
}, 500);
};
It works fine, but if it is started multiple times before one has finished, the counter (x) exceeds 3 and the interval does not stop. How can I avoid that?

That is because you have funcions blink_in & blink_out in global scope. When you are calling it second time it overwrites the definitions of functions.
Define them using var to make them local.
var blink_in = setInterval(function() {..})
and
var blink_out = setInterval(function() {..})
DEMO

Your variables blink_in and blink_out are global ones so if you call the function multiple times they will override it and therefore cannot stop the interval properly.
Use them in your function scope by definining them with "var" in order to avoid the problem (see http://jsfiddle.net/cb0h8tst/)
function blink_three_times(layername){
var x = 0;
var blink_in, blink_out;
setTimeout(function() {
blink_in = setInterval(function() {
x = x+1;
if ( x === 3) {clearInterval(blink_in)};
console.log(layername + ' is visible');
}, 500);
}, 250);
blink_out = setInterval(function() {
if (x === 2) {clearInterval(blink_out)};
console.log(layername + ' is invisible');
}, 500);
};

Based on your last update question,
you could also make a more dynamic to keep track of the layers that are actually being blinked, a possible example
function Blinker(opt) {
var ts = {};
this.elementId = opt ? opt.elementId : undefined;
this.runs = (opt ? opt.runs : 3) || 3;
this.completed = (opt ? opt.completed : function() { }) || function() { };
this.start = function(arg) {
var timestamp = arg || this.elementId, that = this;
if (typeof ts[timestamp] !== 'undefined') {
console.log('Cannot run multiple times on same layer');
return;
}
ts[timestamp] = {
timestamp: timestamp,
count: 0,
element: document.getElementById(arg || this.elementId),
controller: this
};
setTimeout(function() {
ts[timestamp].showInterval = setInterval(that.setVisibility.bind(ts[timestamp], true), 500);
}, 250);
ts[timestamp].hideInterval = setInterval(this.setVisibility.bind(ts[timestamp], false), 500);
};
this.setVisibility = function(visible) {
this.element.style.visibility = visible ? 'visible' : 'hidden';
this.element.style.display = visible ? 'inherit' : 'none';
if (visible) {
this.count++;
}
if (!visible && this.count === 2)
{
clearInterval(this.hideInterval);
}
if (visible && this.count === 3)
{
clearInterval(this.showInterval);
this.controller.completed.apply(this.controller, [this.element.id]);
delete ts[this.timestamp];
}
};
}
var blinker = new Blinker({
elementId: 'blinker',
runs: 3,
completed: function(elementId) {
var log = document.getElementById('log');
log.innerHTML += '<p><strong>' + elementId + '</strong> has finished blinking</p>';
}
});
you could find the fiddle here: http://jsfiddle.net/q70w0kpx/

Accessing a jQuery Closure function outside

I have this code embedded in my file for managing session time out. This was referred from http://www.fairwaytech.com/2012/01/handling-session-timeout-gracefully/
I want to call SessionManager.extend() for all the ajax request
complete. So i can automatically refresh my session manager time.
This is what i tried
<script type="text/javascript">
$(document).ajaxSuccess(function (event, xhr, settings) {
if (xhr.status === 200) {
SessionManager().extend();
}
});
</script>
Getting an error that SessionManager object not found. How do we call this?
Below is the library code taken from that site
$(function () { // Wrap it all in jQuery documentReady because we use jQuery UI Dialog
// HtmlHelpers Module
// Call by using HtmlHelpers.getQueryStringValue("myname");
var HtmlHelpers = function () {
return {
// Based on http://stackoverflow.com/questions/901115/get-query-string-values-in-javascript
getQueryStringValue: function (name) {
var match = RegExp('[?&]' + name + '=([^&]*)').exec(window.location.search);
return match && decodeURIComponent(match[1].replace(/\+/g, ' '));
}
};
} ();
// StringHelpers Module
// Call by using StringHelpers.padLeft("1", "000");
var StringHelpers = function () {
return {
// Pad string using padMask. string '1' with padMask '000' will produce '001'.
padLeft: function (string, padMask) {
string = '' + string;
return (padMask.substr(0, (padMask.length - string.length)) + string);
}
};
} ();
// SessionManager Module
var SessionManager = function () {
// NOTE: globalTimeoutPeriod is defined in _Layout.cshtml
var sessionTimeoutSeconds = HtmlHelpers.getQueryStringValue('smt') || (globalTimeoutPeriod),
countdownSeconds = HtmlHelpers.getQueryStringValue('smc') || 300,
secondsBeforePrompt = sessionTimeoutSeconds - countdownSeconds,
$dlg,
displayCountdownIntervalId,
promptToExtendSessionTimeoutId,
originalTitle = document.title,
count = countdownSeconds,
extendSessionUrl = '/Session/Extend',
expireSessionUrl = '/Session/Expire?returnUrl=' + location.pathname;
var endSession = function () {
$dlg.dialog('close');
location.href = expireSessionUrl;
};
var displayCountdown = function () {
var countdown = function () {
var cd = new Date(count * 1000),
minutes = cd.getUTCMinutes(),
seconds = cd.getUTCSeconds(),
minutesDisplay = minutes === 1 ? '1 minute ' : minutes === 0 ? '' : minutes + ' minutes ',
secondsDisplay = seconds === 1 ? '1 second' : seconds + ' seconds',
cdDisplay = minutesDisplay + secondsDisplay;
document.title = 'Expire in ' +
StringHelpers.padLeft(minutes, '00') + ':' +
StringHelpers.padLeft(seconds, '00');
$('#sm-countdown').html(cdDisplay);
if (count === 0) {
document.title = 'Session Expired';
endSession();
}
count--;
};
countdown();
displayCountdownIntervalId = window.setInterval(countdown, 1000);
};
var promptToExtendSession = function () {
$dlg = $('#sm-countdown-dialog')
.dialog({
title: 'Session Timeout Warning',
height: 250,
width: 350,
bgiframe: true,
modal: true,
buttons: {
'Continue': function () {
$(this).dialog('close');
refreshSession();
document.title = originalTitle;
},
'Log Out': function () {
endSession(false);
}
}
});
count = countdownSeconds;
displayCountdown();
};
var refreshSession = function () {
window.clearInterval(displayCountdownIntervalId);
var img = new Image(1, 1);
img.src = extendSessionUrl;
window.clearTimeout(promptToExtendSessionTimeoutId);
startSessionManager();
};
var startSessionManager = function () {
promptToExtendSessionTimeoutId =
window.setTimeout(promptToExtendSession, secondsBeforePrompt * 1000);
};
// Public Functions
return {
start: function () {
startSessionManager();
},
extend: function () {
refreshSession();
}
};
} ();
SessionManager.start();
});

Remove the var prefix from SessionManager.
Bit of info here about scope, http://msdn.microsoft.com/en-us/library/ie/bzt2dkta(v=vs.94).aspx