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Setting interval only once by an event listener, but run other functions every time

See this code:
function handleTouchStart(event) {
event.preventDefault();
cnvs.removeEventListener("touchstart", handleTouchStart);
var x1 = event.touches[0].clientX-cnvs.offsetLeft;
callerOfCNVSTouchStart = setInterval(function () {
if (x1 > cnvs.width/2 && whiteShip.x2 < cnvs.width) {
whiteShip.x1+= 3;
} else if (x1 < cnvs.width/2 && whiteShip.x1 > 0) {
whiteShip.x1-= 3;
}
}, 20);
nBMC = setInterval(makeNewBullets,200);
setInterval(sendEnemies,2000);//I want to run this line only once
}
I want the other functions to run every time the event occurs, but set the interval for sendEnemies only once. How can I do that?

Use a variable like var sentEnemies = false; outside function handleTouchStart and update it in the function to true the first time and use if(!sentEnemies) for the line to execute only once.
var sentEnemies = false;
function handleTouchStart(event) {
event.preventDefault();
cnvs.removeEventListener("touchstart", handleTouchStart);
var x1 = event.touches[0].clientX-cnvs.offsetLeft;
callerOfCNVSTouchStart = setInterval(function () {
if (x1 > cnvs.width/2 && whiteShip.x2 < cnvs.width) {
whiteShip.x1+= 3;
} else if (x1 < cnvs.width/2 && whiteShip.x1 > 0) {
whiteShip.x1-= 3;
}
}, 20);
nBMC = setInterval(makeNewBullets,200);
if (!sentEnemies) {
setInterval(sendEnemies,2000); // Will execute only once
sentEnemies = true;
}
}

Adding timeout to a loop

I have a function that will perform an action when the timer reaches 5000ms:
var timer = new Timer(function () {
console.log("refreshingBid");
refreshBid();
}, 5000);
timer.pause();
if (isElementInViewport() === true) {
console.log("element in view");
timer.resume();
} else {
timer.pause();
console.log("element is out of view")
}
//I am trying to loop this 5 times with the 5000ms delay - the code I am using for this is:
for (i=0;i<=5;i++)
{
MyFunc();
}
It seems regardless of whether I put the for loop in the timer or whether I put the timer inside the for loop the result is the same where all 5 loops happen instantaneously instead of with a delay of the timer being applied? I'm not sure what i'm doing wrong here... Any help would be appreciated!
Sorry, edit to include the complete code below:
<script>
var iframe2 = document.getElementById('postbid_if');
function isElementInViewport() {
var el = document.getElementById('postbid_if')
console.log(el)
var rect = el.getBoundingClientRect();
console.log(rect)
return rect.bottom >= 0 &&
rect.right >= 0 &&
rect.left < (window.innerWidth || document.documentElement.clientWidth) &&
rect.top < (window.innerHeight || document.documentElement.clientHeight);
}
function Timer(callback, delay) {
var timerId, start, remaining = delay;
this.pause = function () {
window.clearTimeout(timerId);
remaining -= new Date() - start;
};
this.resume = function () {
start = new Date();
window.clearTimeout(timerId);
timerId = window.setTimeout(callback, remaining);
};
this.resume();
}
for (i = 0; i <= 5; i++) {
MyFunc();
}
var timer = new Timer(function () {
console.log("refreshingBid");
refreshBid();
}, 5000);
timer.pause();
if (isElementInViewport() === true) {
console.log("element in view");
timer.resume();
} else {
timer.pause();
console.log("element is out of view")
}
</script>

It's because it's looping through quickly 5 times then all 5 loops are delaying after the 5 seconds. The timeout pauses it after 5 seconds, not for 5 seconds up front.

Perhaps you could revise your code in this way to achieve the timer based iterations as required:
//Track the current iteration
var i = 0;
function MyFunc() {
var timer = new Timer(function () {
console.log("refreshingBid");
refreshBid();
// The current timer has completed. If the current
// iteration is less than 5...
if(i < 5) {
i++;
// .. then start another timer for the next iteration
MyFunc();
}
}, 5000);
timer.pause();
if (isElementInViewport() === true) {
console.log("element in view");
timer.resume();
} else {
timer.pause();
console.log("element is out of view")
}
}
// Start the first iteration
MyFunc();

Making a timer with code that can easily be reset

I'm making a shot clock for my school's basketball team. A shot clock is a timer that counts down from 24 seconds. I have the skeleton for the timer right now, but I need to have particular key bindings. The key bindings should allow me to rest, pause, and play the timer.
var count=24;
var counter=setInterval(timer, 1000);
function timer()
{
count=count-1;
if (count <= 0)
{
clearInterval(counter);
return;
}
document.getElementById("timer").innerHTML=count + " secs";
}

I'm not sure what you meant by "rest" the timer, I interpret this as "pause", so:
Space = Pause / Play.
R = Reset.
var
count=24,
counter = setInterval(timer, 1000),
running = true;
function timer() {
count -= 1;
if (count <= 0) {
clearInterval(counter);
}
document.getElementById("timer").innerHTML = count + " secs";
}
window.addEventListener("keydown", function(e) {
switch(e.keyCode) {
case 32: // PLAY
running ? clearInterval(counter) : counter = setInterval(timer, 1000);
running = !running;
break;
case 82: // RESET
clearInterval(counter);
document.getElementById("timer").innerHTML = 24 + " secs";
count = 24;
running = false;
}
});
<div id="timer">24 secs</div>

I am not able to comment yet, but I recommend checking out this post Binding arrow keys in JS/jQuery
The linked post explains how to bind arrow keys using js/jquery. Using http://keycode.info/ you can find out the keycodes of your desired keys and replace the current values then continue to build your code from there.

Here is my code sample: http://codepen.io/anon/pen/vLvWJM
$(document).ready(function() {
var $timer = $('#timer');
var $timerStatus = $('#timerStatus');
var timerValue = 24;
var intervalId = null;
var timerStatus = 'stopped';
if(!$timer.length) {
throw 'This timer is missing a <div> element.';
}
$(document).keydown(function(k) {
if(k.which == 80) {
if(timerStatus === 'playing') {
clearInterval(intervalId);
timerStatus = 'stopped';
updateTimerStatus();
return;
}
intervalId = setInterval(function() {
playTimer();
timerStatus = 'playing';
updateTimerStatus();
}, 1000);
} else if(k.which == 82) {
clearInterval(intervalId);
resetTimer();
updateText();
timerStatus = 'stopped';
updateTimerStatus();
}
});
function playTimer() {
if(timerValue > 0) {
timerValue--;
updateText();
}
}
function resetTimer() {
timerValue = 24;
}
function updateText() {
$timer.html(timerValue);
}
function updateTimerStatus() {
$timerStatus.html(timerStatus);
}
});
<div id="timerStatus">stopped</div>
<div id="timer">24</div>

Restart setInterval each minute

To create a ticking movement and not a sliding one of a number on a canvas i want to move the number up in 0,2 secondes and wait 0,8 seconds. The codes works good for a sliding movement but to implement the ticking i get lost.
jsfiddle
var ittt = 0;
var add = null;
function MinuteTimer() {
add = setInterval(function () {
totime();
if (ittt % (40 * 60) == 0) {
ittt = 0;
}
}, 5);
};
function stoptimer() {
clearInterval(add);
};
function totime() {
drawcanvasbackground();
drawnumberscanvas(ittt);
ittt += 1;
if (ittt % 40 == 0 && ittt > 0) {
clearInterval(add);
setTimeout(MinuteTimer(), 800);
};
};

JavaScript to delay execution of functions after page is loaded

I wrote this javascript to make an animation. It is working fine in the home page. I wrote a alert message in the last.
If I go other then home page, this alert message has to come, but I am getting alert message, if I remove the function, alert message working on all pages, any thing wrong in my code?
window.onload = function(){
var yellows = document.getElementById('magazine-brief').getElementsByTagName('h2');
var signUp = document.getElementById('signup-link');
if (yellows != 'undefined' && signUp != undefined){
function animeYellowBar(num){
setTimeout(function(){
yellows[num].style.left = "0";
if(num == yellows.length-1){
setTimeout(function(){
signUp.style.webkitTransform = "scale(1)";
},num*250);
}
}, num * 500);
}
for (var i = 0; i < yellows.length; i++){
animeYellowBar(i);
}
}
alert('hi');
}

DEMO: http://jsbin.com/enaqu5/2
var yellows,signUp;
window.onload = function() {
yellows = document.getElementById('magazine-brief').getElementsByTagName('h2');
signUp = document.getElementById('signup-link');
if (yellows !== undefined && signUp !== undefined) {
for (var i = 0; i < yellows.length; i++) {
animeYellowBar(i);
}
}
alert('hi')
}
function animeYellowBar(num) {
setTimeout(function() {
yellows[num].style.left = "0";
if (num == yellows.length - 1) {
setTimeout(function() {
signUp.style.webkitTransform = "scale(1)";
},
num * 250);
}
},
num * 500);
}
DEMO 2: http://jsbin.com/utixi4 (just for sake)
$(function() {
$("#magazine-brief h2").each(function(i,item) {
$(this).delay(i+'00').animate({'marginLeft': 0 }, 500 ,function(){
if ( i === ( $('#magazine-brief h2').length - 1 ) )
$('#signup-link')[0].style.webkitTransform = "rotate(-2deg)";
});
});
});

For starters you are not clearing your SetTimeout and what are you truly after here? You have 2 anonymous methods that one triggers after half a second and the other triggers a quarter of a second later.
So this is just 2 delayed function calls with horribly broken syntax.
Edited Two possibilities, one fixes your current code... the latter shows you how to do it using JQuery which I would recomend:
var yellows, signUp;
window.onload = function(){
yellows = document.getElementById('magazine-brief');
if(yellows != null){
yellows = yellows.getElementsByTagName('h2');
}else{
yellows = null;
}
signUp = document.getElementById('signup-link');
if (yellows != null && signUp != null && yellows.length > 0)
{
for(var i = 0; i < yellows.length; i++)
{
animeYellowBar(i);
}
}
alert('hi');
}
function animeYellowBar(num)
{
setTimeout(function(){
yellows[num].style.left = "0";
if(num == yellows.length-1){
setTimeout(function(){
signUp.style.webkitTransform = "scale(1)";
},num*250);
}
}, num * 500);
}
The below approach is a SUMMARY of how to use JQuery, if you want to use JQuery I'll actually test it out:
//Or using JQuery
//Onload equivelent
$(function(){
var iterCount = 0,
maxIter = $("#magazine-brief").filter("h2").length;
$("#magazine-brief").filter("h2").each(function(){
setTimeout(function(){
$(this).css({left: 0});
if(iterCount == (maxIter-1))
{
setTimeout(function(){
signUp.style.webkitTransform = "scale(1)";
},iterCount*250);
}
}, iterCount++ * num );
});
});