Javascript scope error issue - javascript

I wrote this code that starts a timer. I fire a function that restarts the timer when it reaches 0. It works, but I get an error in the console that says Uncaught TypeError: Cannot read property 'restartTimer' of undefined. It has to do with this.restartTimer();
timer = utility.math.surveyTimer({
seconds: time,
onUpdateStatus: function(remainingTime) {
$(surveyTimerNode).text(remainingTime);
},
restartTimer: function() {
window.TimerInterval = timer.start();
},
onCounterEnd: function() {
if (utility.bool.isQuestionScreen()) {
if (utility.bool.surveyWillLoop()) {
data.setPersistentSurveyData('DSM_SURVEY_SCREENS', surveyScreens);
data.setPersistentSurveyData('DSM_SURVEY_SCREEN_ORDER', surveyScreenOrder);
tagData = data.getPersistentSurveyData('DSM_SURVEY_DATA');
apiParam = api.helper.buildAPIParam('surveyTimeout', tagData);
api.post.postToAPI(apiParam);
parent.resetSurveyProgress();
parent.moveToNextScreen();
this.restartTimer();
} else {
parent.goToEndscreen();
}
}
}
});
window.TimerInterval = timer.start();
No errors in JSLint, just errors on run. What's so bizarre is that it works, the timer does reset. How do I remove this error?
Here's the function that actually does the timer counting:
this.surveyTimer = function (options) {
var timer,
instance = this,
minutes,
secondsMinusMinutes,
remainingTime,
seconds = options.seconds || 30,
updateStatus = options.onUpdateStatus || function () {
return undefined;
},
counterEnd = options.onCounterEnd || function () {
return undefined;
};
function zeroPad(n) {
return (n < 10) ? ("0" + n) : n;
}
function decrementCounter() {
minutes = Math.floor(seconds / 60);
secondsMinusMinutes = seconds - minutes * 60;
remainingTime = minutes + ':' + zeroPad(secondsMinusMinutes);
updateStatus(remainingTime);
if (seconds === 0) {
counterEnd();
instance.stop();
}
seconds -= 1;
}
this.start = function () {
clearInterval(timer);
timer = 0;
seconds = options.seconds;
timer = setInterval(decrementCounter, 1000);
return timer;
};
this.stop = function () {
clearInterval(timer);
};
return this;
};

Just a guess, but I think your use of this in your options object is not the this you think it is...
Try changing your implementation of surveyTimer, where it is currently:
counterEnd();
to:
counterEnd.call(options);

Related

Countdown timer stops when switching tabs

So basically when I switch tabs, the countdown timer on a specific page just stops counting down and resumes when you return to the tab. Is there anyway to mitigate that so that it counts in the background or it accounts for the time you spend on another tab?
This is basically what I have for js:
document.getElementById('timer').innerHTML =
05 + ":" + 01;
startTimer();
function startTimer() {
var presentTime = document.getElementById('timer').innerHTML;
var timeArray = presentTime.split(/[:]+/);
var m = timeArray[0];
var s = checkSecond((timeArray[1] - 1));
if(s==59){m=m-1}
if(m<0){
return
} else if (m == 0 && s == 0) {
location.reload();
}
document.getElementById('timer').innerHTML =
m + ":" + s;
setTimeout(startTimer, 1000);
}
function checkSecond(sec) {
if (sec < 10 && sec >= 0) {sec = "0" + sec};
if (sec < 0) {sec = "59"};
return sec;
}
Any ideas whether the time could be done server side or something so that it can't be modified client side? If not, then whatever, but mainly just want to figure out how to make the countdown still work (or account for the time spent) when on another tab.
We can store the variable m and s values either globally or use the local storage to set the values after setting the inner HTML and get the stored values back whenever tabs were switched as:
Set values:
window.localStorage.setItem('minutes', m.toString()); //same for the seconds
Get values:
window.localStorage.getItem('minutes'); //same for the seconds
Hope this answers your questions.
Just a simple solution:
Add this piece of code.
<html>
<head>
<script>
(function() {
var $momentum;
function createWorker() {
var containerFunction = function() {
var idMap = {};
self.onmessage = function(e) {
if (e.data.type === 'setInterval') {
idMap[e.data.id] = setInterval(function() {
self.postMessage({
type: 'fire',
id: e.data.id
});
}, e.data.delay);
} else if (e.data.type === 'clearInterval') {
clearInterval(idMap[e.data.id]);
delete idMap[e.data.id];
} else if (e.data.type === 'setTimeout') {
idMap[e.data.id] = setTimeout(function() {
self.postMessage({
type: 'fire',
id: e.data.id
});
// remove reference to this timeout after is finished
delete idMap[e.data.id];
}, e.data.delay);
} else if (e.data.type === 'clearCallback') {
clearTimeout(idMap[e.data.id]);
delete idMap[e.data.id];
}
};
};
return new Worker(URL.createObjectURL(new Blob([
'(',
containerFunction.toString(),
')();'
], {
type: 'application/javascript'
})));
}
$momentum = {
worker: createWorker(),
idToCallback: {},
currentId: 0
};
function generateId() {
return $momentum.currentId++;
}
function patchedSetInterval(callback, delay) {
var intervalId = generateId();
$momentum.idToCallback[intervalId] = callback;
$momentum.worker.postMessage({
type: 'setInterval',
delay: delay,
id: intervalId
});
return intervalId;
}
function patchedClearInterval(intervalId) {
$momentum.worker.postMessage({
type: 'clearInterval',
id: intervalId
});
delete $momentum.idToCallback[intervalId];
}
function patchedSetTimeout(callback, delay) {
var intervalId = generateId();
$momentum.idToCallback[intervalId] = function() {
callback();
delete $momentum.idToCallback[intervalId];
};
$momentum.worker.postMessage({
type: 'setTimeout',
delay: delay,
id: intervalId
});
return intervalId;
}
function patchedClearTimeout(intervalId) {
$momentum.worker.postMessage({
type: 'clearInterval',
id: intervalId
});
delete $momentum.idToCallback[intervalId];
}
$momentum.worker.onmessage = function(e) {
if (e.data.type === 'fire') {
$momentum.idToCallback[e.data.id]();
}
};
window.$momentum = $momentum;
window.setInterval = patchedSetInterval;
window.clearInterval = patchedClearInterval;
window.setTimeout = patchedSetTimeout;
window.clearTimeout = patchedClearTimeout;
})();
</script>
</head>
</html>

localStorage how to save countdown value so it wont reset when I reload the page

When I reload the page, my 1 minute countdown also reloads.
I tried to use localStorage but it seems to me failed.
Please have a look, I do not know where I should fix.
Thank you
My script
/* for countdown */
var countDown = (function ($) {
// Length ms
var timeOut = 10000;
// Interval ms
var timeGap = 1000;
var currentTime = (new Date()).getTime();
var endTime = (new Date()).getTime() + timeOut;
var guiTimer = $("#clock");
var running = true;
var timeOutAlert = $("#timeout-alert");
timeOutAlert.hide();
var updateTimer = function() {
// Run till timeout
if(currentTime + timeGap < endTime) {
setTimeout( updateTimer, timeGap );
}
// Countdown if running
if(running) {
currentTime += timeGap;
if(currentTime >= endTime) { // if its over
guiTimer.css("color","red");
}
}
// Update Gui
var time = new Date();
time.setTime(endTime - currentTime);
var minutes = time.getMinutes();
var seconds = time.getSeconds();
guiTimer.html((minutes < 10 ? '0' : '') + minutes + ':' + (seconds < 10 ? '0' : '') + seconds);
if (parseInt(guiTimer.html().substr(3)) <= 10){ // alert the user that he is running out of time
guiTimer.css('color','red');
timeOutAlert.show();
}
};
var pause = function() {
running = false;
};
var resume = function() {
running = true;
};
var start = function(timeout) {
timeOut = timeout;
currentTime = (new Date()).getTime();
endTime = (new Date()).getTime() + timeOut;
updateTimer();
};
return {
pause: pause,
resume: resume,
start: start
};
})(jQuery);
jQuery('#break').on('click',countDown.pause);
jQuery('#continue').on('click',countDown.resume);
var seconds = 60; // seconds we want to count down
countDown.start(seconds*1000);
I tried to fix it but I dont know where/how to put localStorage.
This may help you.
HTML Code:
<div id="divCounter"></div>
JS Code
var test = 60;
if (localStorage.getItem("counter")) {
if (localStorage.getItem("counter") <= 0) {
var value = test;
alert(value);
} else {
var value = localStorage.getItem("counter");
}
} else {
var value = test;
}
document.getElementById('divCounter').innerHTML = value;
var counter = function() {
if (value <= 0) {
localStorage.setItem("counter", test);
value = test;
} else {
value = parseInt(value) - 1;
localStorage.setItem("counter", value);
}
document.getElementById('divCounter').innerHTML = value;
};
var interval = setInterval(function() { counter(); }, 1000);

Closure in timer countdown javascript

I'm using the countdown timer from here: The simplest possible JavaScript countdown timer?
I'm adding the reset, pause and resume functionalities to the code.
//=================== Timer class ==============================
function CountDownTimer(duration, granularity) {
this.duration = duration
this.granularity = granularity || 1000;
this.tickFtns = [];
this.running = false;
this.resetFlag = false;
}
CountDownTimer.prototype.start = function() {
console.log('calling start');
if (this.running) {
return;
}
this.running = true;
var start = Date.now(),
that = this,
diff, obj,
timeoutID;
(function timer() {
diff = that.duration - (((Date.now() - start) / 1000) | 0);
if (that.resetFlag) {
console.log('Reset inside closure');
clearTimeout(timeoutID);
diff = 0;
that.resetFlag = false;
that.running = false;
return;
}
console.log(diff);
if (diff > 0) {
timeoutID = setTimeout(timer, that.granularity);
} else {
diff = 0;
that.running = false;
}
obj = CountDownTimer.parse(diff);
that.tickFtns.forEach(function(ftn) {
ftn.call(this, obj.minutes, obj.seconds);
}, that);
}());
};
CountDownTimer.prototype.onTick = function(ftn) {
if (typeof ftn === 'function') {
this.tickFtns.push(ftn);
}
return this;
};
CountDownTimer.prototype.expired = function() {
return !this.running;
};
CountDownTimer.prototype.setTime = function(secs) {
this.duration = secs;
}
CountDownTimer.prototype.reset = function() {
this.resetFlag = true;
}
CountDownTimer.parse = function(seconds) {
return {
'minutes': (seconds / 60) | 0,
'seconds': (seconds % 60) | 0
};
};
window.onload = function () {
timer = new CountDownTimer(25);
timer.start();
$('#button').click(function() {
console.log("before reset");
console.log(timer);
console.log("after reset");
timer.reset();
console.log(timer);
// timer.setTime(10);
timer.start();
})
}
HTML for testing, check the output at console.
<script src="main.js"></script>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.12.4/jquery.min.js"></script>
<button id='button'> </button>
1) Is function timer() in start a closure?
2) I added a resetFlag, the reset method, and the check for resetFlag in the start function. I'm able to stop the timer immediately, but can't start it after that. How do I fix the error?
25
24
23
main.js:64 Reset inside closure
(it supposed to countdown from 25 to 0, and when I press #button, the timer reset and should count from 10 to 0.
================================EDITS==========================================:
After adding running = false, it's still not working.
before reset
main.js:128 CountDownTimer {duration: 25, granularity: 1000, tickFtns: Array[0], running: true, resetFlag: false}
main.js:129 after reset
main.js:131 CountDownTimer {duration: 25, granularity: 1000, tickFtns: Array[0], running: true, resetFlag: true}
calling start
main.js:64 Reset inside closure
It seems that there's some lag after resetting the timer? (The reset inside closure suppposed to appear before the after reset.

Countdown and bootstrap progress bar "bump"

I'm working on a little "web app" for a quiz.
Each slide has got a certain amount of time to be answered (or 0 to infinite time).
I find JS here to do the countdown:
function Countdown(options) {
var timer,
instance = this,
seconds = options.seconds || 10,
updateStatus = options.onUpdateStatus || function () {},
counterEnd = options.onCounterEnd || function () {};
function decrementCounter() {
updateStatus(seconds);
if (seconds === 0) {
counterEnd();
instance.stop();
}
seconds--;
}
this.start = function () {
clearInterval(timer);
timer = 0;
seconds = options.seconds;
timer = setInterval(decrementCounter, 1000);
};
this.stop = function () {
clearInterval(timer);
};
}
var myCounter = new Countdown({
seconds: timetogo, // number of seconds to count down
onUpdateStatus: function (sec) {
elapsed = timetogo - sec;
$('.progress-bar').width(((elapsed / timetogo) * 100) + "%");
}, // callback for each second
onCounterEnd: function () {
//alert('counter ended!');
} // final action
});
myCounter.start();
I made a jsfiddle here :
https://jsfiddle.net/mitchum/kz2400cc/2/
But i am having trouble when you go to the next slide, the progress bar "bump".
after looking into "live source panel from chrome" I saw it's like the first "counter" is not stopped and still runs.
Do you have any tips or hint to help me to solve my bug ?
Thanks
You must pay attention to the scope of the variables. I change the "var myCounter" under document ready in "var myCounterFirst". Check the updated JSFiddle.
var timetogoFirst = $('.current').attr("data-time");
var myCounterFirst = new Countdown({
seconds: timetogoFirst, // number of seconds to count down
onUpdateStatus: function (sec) {
elapsed = timetogoFirst - sec;
$('.progress-bar').width(((elapsed / timetogoFirst) * 100) + "%");
}, // callback for each second
onCounterEnd: function () {
alert('counter ended!');
} // final action
});
myCounterFirst.start();

JS- Countdown Timer Alerts

Need some help with my code, I can't get my alerts to work with my countdown timer. They should be alerting at 4,3,2 minutes left on the timer. I currently can't get the alerts to fire at all, sometimes they would fire but each second after 4, the alert for "4" would fire. I need it to just go once... Any help would be appreciated
Heres my script
var running=false
var endTime=null
var timerID=null
function startTimer(){
running=true
now=new Date()
now=now.getTime()
endTime=now+(1000*60*5)
showCountDown()
}
function showCountDown(){
var now=new Date()
now=now.getTime()
if (endTime-now<=239990 && endTime-now>240010){alert("4")};
if (endTime-now<=179990 && endTime-now>180010){alert("3")};
if (endTime-now<=119990 && endTime-now>120010){alert("2")};
if (endTime-now<=0){
stopTimer()
alert("Time is up. Put down pencils")
} else {
var delta=new Date(endTime-now)
var theMin=delta.getMinutes()
var theSec=delta.getSeconds()
var theTime=theMin
theTime+=((theSec<10)?":0" : ":")+theSec
document.forms[0].timerDisplay.value=theTime
if (running){
timeID=setTimeout("showCountDown()",1000)
}
}
}
function stopTimer(){
clearTimeout(timeID)
running=false
document.forms[0].timerDisplay.value="0.00"
}
Update, Sorry meant minutes instead of seconds
Update 2: Change the ifs, now they fire but keep firing after the 4 second mark
if (endTime-now<=240010 && endTime-now<=239990){alert("4")};
if (endTime-now<=180010 && endTime-now<=179990){alert("3")};
if (endTime-now<=120010 && endTime-now<=119990){alert("2")};
Why are you calling clearTimeout? setTimeout invokes its callback only once. There is no need to clear it. Also you could just have a variable that stores the minutes until the end of the countdown and decrement that by one in each iteration.
The simplest solution might look like this
function startTimer(minutesToEnd) {
if(minutesToEnd > 0) {
if(minutesToEnd <= 4) {
console.log(minutesToEnd);
}
setTimeout(startTimer, 60000, minutesToEnd - 1);
} else {
console.log("Time is up. Put down pencils")
}
}
I actually spent some time working on this. I have no idea if this is what you wanted, but I created a timer library. I have a working demo for you. I had fun making this. Let me know what you think:
JS:
(function () {
var t = function (o) {
if (!(this instanceof t)) {
return new t(o);
}
this.target = o.target || null;
this.message = o.message;
this.endMessage = o.endMessage;
//setInterval id
this.si = -1;
//Initial start and end
this.startTime = null;
this.endTime = null;
this.interTime = null;
this.duration = o.duration || 1000 * 60 * 5;
//looping speed miliseconds it is best to put the loop at a faster speed so it doesn't miss out on something
this.loop = o.loop || 300;
//showing results miliseconds
this.show = o.show || 1000;
};
t.fn = t.prototype = {
init: function () {}
};
//exporting
window.t = t;
})();
//Timer Functions ---
t.fn.start = function () {
this.startTime = new Date();
this.interTime = this.startTime.getTime();
this.endTime = new Date().setMilliseconds(this.startTime.getMilliseconds() + this.duration);
//returns undefined... for some reason.
console.log(this.endTime);
var $this = this;
this.writeMessage(this.duration);
this.si = setInterval(function () {
var current = new Date(),
milli = current.getTime();
if (milli - $this.interTime >= $this.show) {
var left = $this.endTime- milli;
if (left <= 0) {
$this.stop();
} else {
$this.interTime = milli;
$this.writeMessage(left);
}
}
}, this.loop);
return this;
};
t.fn.writeMessage = function(left){
this.target.innerHTML = this.message + ' ' + Math.floor(left / 1000);
return this;
};
t.fn.stop = function () {
//stopping the timer
clearInterval(this.si);
this.target.innerHTML = this.endMessage;
return this;
};
//Not chainable
t.fn.isRunning = function () {
return this.timer > -1;
};
var timer = t({
target: document.getElementById('results'),
loop: 50,
duration: 10000,
show: 1000, //default is at 1000 miliseconds
message: 'Time left: ', //If this is ommited then only the time left will be shown
endMessage: 'Time is up. Put down your pencils'
}).start();
document.getElementById('stop').onclick = function(){
timer.stop();
};
HTML:
<div id="results"></div>
<button id="stop">Stop</button>
Demo here
Update: I added some stuff
Demo 2
Update 2: I fixed the bug where 10 would hop straight to 8
Demo 3

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