I want the alertMe function to be called only when the button is clicked, but it gets called (the setInterval gets called which calls that) AS SOON AS THE PAGE LOADS. But if I take the pageLoad function away, then startButton is null and I can't do anything with it.Thanks in advance, guys!
/when user clicks start, start the animation
window.onload = pageLoad;
function pageLoad() {
var startButton = document.getElementById("start");
startButton.onclick = setInterval(alertMe,200);
}
function alertMe() {
alert("hi");
}
function pageLoad() {
var startButton = document.getElementById("start");
startButton.onclick = alertMe;
}
function alertMe() {
setInterval(function(){
alert("hi");
},200);
}
Move your interval inside the alertMe function, and pass that as a reference to startButton.onclick
DEMO: http://jsfiddle.net/gHS4a/
basically you need to do it like this:
startButton.onclick = function() {
interval = setInterval(alertMe, 200);
}
what it does is it sends reference to the alertMe function
another way would be:
startButton.onclick = function() {
interval = setInterval(function(){
alertMe();
}, 200);
}
which would send a reference to an anonymous function which will call the alertMe function
Related
I have a change() function that uses a setInterval() to repeat an animation:
function change(){
interval = setInterval(c,300);
function c(){...}
c()
}
The c() function does the work.
I also have a stop() function that stops all the animation and restore the initial situation:
function stop(){
clearInterval(interval);
...
};
I've read that is better use the var keyword instead declaring a global variable. But I cannot get access from the stop() function to interval if I do so. Declaring interval outside the change() function also gives me a problem.
ok i'm trying the last solution proposed by Ben Aston. Here the code:
function Animator() {
var id;
return {
start: start,
stop: stop,
};
function start() {
id = requestAnimationFrame(go);
}
function stop() {
clearAnimationFrame(id);
}
function go() {
// increment the animation
for (var i=0;i<img.length;i++){
var num = randNum(0,img.length-1)
var btn = img[i].nextSibling.nextSibling.childNodes[1]
img[i].setAttribute("src",img_path[num].path);
$(btn).css({"background-color":img_path[num].color,"border":"4px solid"+img_path[num].color});
$(img[i]).animate({width: "-=80px", height: "-=80px"},'slow');
$(img[i]).animate({width: "+=80px", height: "+=80px"},'slow')}
id = requestAnimationFrame(go)
}
}
basically when the user press a button, the images start to change their width and height and their color.
this is the rest:
var animator = new Animator();
function stop(){ //fn related to the stop button
animator.stop()};
function change(){ //fn related to the start button
animator.start()}
I dont know how to use requestAnimationFrame properly, i'm studying it right now. but when i press the start button the images change just one time and then they stopped.
In the previous code i had a for loop that did the work:
function change(){
interval = setInterval(c,300);
function c(){
for (var i=0;i<img.length;i++){
var num = randNum(0,img.length-1)
var btn = img[i].nextSibling.nextSibling.childNodes[1]
img[i].setAttribute("src",img_path[num].path);
$(btn).css({"background-color":img_path[num].color,"border":"4px solid"+img_path[num].color});
$(img[i]).animate({width: "-=80px", height: "-=80px"},'slow');
$(img[i]).animate({width: "+=80px", height: "+=80px"},'slow')}}
c()}
I admit that i dont have quite clear how to implement the go func?
thanks
edit: now it works (i was working with another file :)) but i have problem with the stop button
You can use Closure as well, read the documentation here :
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Closures
With Closure you can define private and public function.
In raw JavaScript you could do the following:
Using ES5:
function Animator() {
var id;
return {
start: start,
stop: stop,
};
function start() {
id = requestAnimationFrame(go);
}
function stop() {
clearAnimationFrame(id);
}
function go() {
// increment the animation...
if(shouldContinue()) { // you define `shouldContinue`
id = requestAnimationFrame(go);
}
}
}
var animator = new Animator();
animator.start();
// ...
animator.stop()
hi using closures and with set interval things works properly:
var Button_Obj = function(){
var intervalID;
function start(){
return intervalID = setInterval(change,300) //change is the function that do the animation with a loop, i keep it private
};
function stop(){
clearInterval(intervalID)
};
return {start : start, stop : stop}
now in the global space i have only:
var btn_trigger = new Button_Obj();
and in the button tag i put:
<button style="border:1px solid #9dbbe4;" class="change-button" id="change-order" onclick="btn_trigger.start()" type="button">Start Moving</button>
now the global space is more clean, this implmentation works, with RequestAnimationFrame i have some problem, but i will try with it as well later
I have two elements. When I click the left element I want to change the right element into another element. If the left element is not clicked again the right element changes back to its original state. I've been able to make that happen, but I want to be able to click on that element again and have the interval I set restart. I feel like I'm close.
var changeImage = function(){
if(imageClicked == true){
var Img = document.getElementById('Img');
Img.setAttribute('src', "./images/img2.jpg");
imageTimeout = setTimeout(function(){
var Image = document.getElementById('Image');
Image.setAttribute('src', './images/image.jpg');
}, 3000)
imageClicked = false;
return imageTimeout;
} else {
imageClicked = true;
resetTimer();
}
}
var resetTimer = function(){
clearTimeout(imageTimeout);
window.setTimeout(imageTimeout, 3000);
}
random_image.addEventListener("click", changeImage, false);
The problem is that you are calling setTimeout(function ,delay) without a callback function.
The issue is in this line in the else block:
window.setTimeout(imageTimeout, 3000);
where imageTimeout is not a function, but the id of the timeout.
You need to create a separate function (let's call it timeoutFunction for example) with the timeout code and call it every time you invoke setTimeout.
After you create that function, and call it in the if block as well, change that line to:
imageTimeout = window.setTimeout(timeoutFunction, 3000);
from your code:
function timeoutFunction(){
var flowerImage = document.getElementById('flowerP');
flowerImage.setAttribute('src', './images/flowers.jpg');
}
by the way, you can define that flowerImage variable outside that function once instead of searching the DOM every time.
In order to clear a timeout, you need to call the clearTimeout function with the reference to the object that was returned by window.setTimeout. So you need to change your code to:
var resetTimer = function() {
clearTimeout(timeoutId);
createjs.Sound.stop(playSoundD);
timeoutId = window.setTimeout(imagetimeout, 3000);
console.log("I've been reset");
}
I am trying to have the setTimeout() function start only after I click a button as opposed to when the page loads. Here is my code:
function convert() {
'use strict';
var utcDate = new Date();
var message;
var output = document.getElementById('output2');
message = 'today is ' + utcDate.toUTCString();
if (output.textContent !== undefined) {
output.textContent = message;
} else {
output.innerText = message;
}
document.getElementById('output2').value = message;
}
button.onclick = setTimeout(convert, 5000);
If you want to start on click of the button. Than you this should be the way:
button.onclick = function() { setTimeout(convert, 5000); }
change
button.onclick = setTimeout(convert, 5000);
to
button.onclick = function () { setTimeout(convert, 5000);}
or you could use jQuery if you are already loading the library for something else
$('#idOfButton').click(function () { setTimeout(convert, 5000);}); //more efficient than $.on()
or another way using jQuery
$('#idOfButton').on('click', function () { setTimeout(convert, 5000); });
As with many tasks in programming, there are many ways to accomplish your task
button.onclick = function(){setTimeout(convert, 5000);}
You need to put the setTimeout part in a function. So that last line would look like
button.onclick = function(){setTimeout(convert,5000)}
I try to make a page to go to the startpage after eg. 10sec of inactivity (user not clicking anywhere). I use jQuery for the rest but the set/clear in my test function are pure javascript.
In my frustation I ended up with something like this function that I hoped I could call on any click on the page. The timer starts fine, but is not reset on a click. If the function is called 5 times within the first 10 seconds, then 5 alerts will apear... no clearTimeout...
function endAndStartTimer() {
window.clearTimeout(timer);
var timer;
//var millisecBeforeRedirect = 10000;
timer = window.setTimeout(function(){alert('Hello!');},10000);
}
Any one got some lines of code that will do the trick?
- on any click stop, reset and start the timer.
- When timer hits eg. 10sec do something.
You need to declare timer outside the function. Otherwise, you get a brand new variable on each function invocation.
var timer;
function endAndStartTimer() {
window.clearTimeout(timer);
//var millisecBeforeRedirect = 10000;
timer = window.setTimeout(function(){alert('Hello!');},10000);
}
The problem is that the timer variable is local, and its value is lost after each function call.
You need to persist it, you can put it outside the function, or if you don't want to expose the variable as global, you can store it in a closure, e.g.:
var endAndStartTimer = (function () {
var timer; // variable persisted here
return function () {
window.clearTimeout(timer);
//var millisecBeforeRedirect = 10000;
timer = window.setTimeout(function(){alert('Hello!');},10000);
};
})();
That's because timer is a local variable to your function.
Try creating it outside of the function.
A way to use this in react:
class Timeout extends Component {
constructor(props){
super(props)
this.state = {
timeout: null
}
}
userTimeout(){
const { timeout } = this.state;
clearTimeout(timeout);
this.setState({
timeout: setTimeout(() => {this.callAPI()}, 250)
})
}
}
Helpful if you'd like to only call an API after the user has stopped typing for instance. The userTimeout function could be bound via onKeyUp to an input.
Not sure if this violates some good practice coding rule but I usually come out with this one:
if(typeof __t == 'undefined')
__t = 0;
clearTimeout(__t);
__t = setTimeout(callback, 1000);
This prevent the need to declare the timer out of the function.
EDIT: this also don't declare a new variable at each invocation, but always recycle the same.
Hope this helps.
Practical example Using Jquery for a dropdown menu !
On mouse over on #IconLoggedinUxExternal shows div#ExternalMenuLogin and set time out to hide the div#ExternalMenuLogin
On mouse over on div#ExternalMenuLogin it cancels the timeout.
On mouse out on div#ExternalMenuLogin it sets the timeout.
The point here is always to invoke clearTimeout before set the timeout, as so, avoiding double calls
var ExternalMenuLoginTO;
$('#IconLoggedinUxExternal').on('mouseover mouseenter', function () {
clearTimeout( ExternalMenuLoginTO )
$("#ExternalMenuLogin").show()
});
$('#IconLoggedinUxExternal').on('mouseleave mouseout', function () {
clearTimeout( ExternalMenuLoginTO )
ExternalMenuLoginTO = setTimeout(
function () {
$("#ExternalMenuLogin").hide()
}
,1000
);
$("#ExternalMenuLogin").show()
});
$('#ExternalMenuLogin').on('mouseover mouseenter', function () {
clearTimeout( ExternalMenuLoginTO )
});
$('#ExternalMenuLogin').on('mouseleave mouseout', function () {
clearTimeout( ExternalMenuLoginTO )
ExternalMenuLoginTO = setTimeout(
function () {
$("#ExternalMenuLogin").hide()
}
,500
);
});
This works well. It's a manager I've made to handle hold events. Has events for hold, and for when you let go.
function onUserHold(element, func, hold, clearfunc) {
//var holdTime = 0;
var holdTimeout;
element.addEventListener('mousedown', function(e) {
holdTimeout = setTimeout(function() {
func();
clearTimeout(holdTimeout);
holdTime = 0;
}, hold);
//alert('UU');
});
element.addEventListener('mouseup', clearTime);
element.addEventListener('mouseout', clearTime);
function clearTime() {
clearTimeout(holdTimeout);
holdTime = 0;
if(clearfunc) {
clearfunc();
}
}
}
The element parameter is the one which you hold. The func parameter fires when it holds for a number of milliseconds specified by the parameter hold. The clearfunc param is optional and if it is given, it will get fired if the user lets go or leaves the element. You can also do some work-arounds to get the features you want. Enjoy! :)
<!DOCTYPE html>
<html>
<body>
<h2>EJEMPLO CONOMETRO CANCELABLE</h2>
<button onclick="inicioStart()">INICIO</button>
<input type="text" id="demostracion">
<button onclick="finStop()">FIN</button>
<script>
let cuenta = 0;
let temporalTiempo;
let statusTime = false;
function cronometro() {
document.getElementById("demostracion").value = cuenta;
cuenta++;
temporalTiempo = setTimeout(cronometro, 500);
}
function inicioStart() {
if (!Boolean(statusTime)) {
statusTime = true;
cronometro();
}
}
function finStop() {
clearTimeout(temporalTiempo);
statusTime = false;
}
</script>
</body>
</html>
I have the following:
window.setTimeout(function() {
window.location.href = 'file.php';
}, 115000);
How can I, via a .click function, reset the counter midway through the countdown?
You can store a reference to that timeout, and then call clearTimeout on that reference.
// in the example above, assign the result
var timeoutHandle = window.setTimeout(...);
// in your click function, call clearTimeout
window.clearTimeout(timeoutHandle);
// then call setTimeout again to reset the timer
timeoutHandle = window.setTimeout(...);
clearTimeout() and feed the reference of the setTimeout, which will be a number. Then re-invoke it:
var initial;
function invocation() {
alert('invoked')
initial = window.setTimeout(
function() {
document.body.style.backgroundColor = 'black'
}, 5000);
}
invocation();
document.body.onclick = function() {
alert('stopped')
clearTimeout( initial )
// re-invoke invocation()
}
In this example, if you don't click on the body element in 5 seconds the background color will be black.
Reference:
https://developer.mozilla.org/en/DOM/window.clearTimeout
https://developer.mozilla.org/En/Window.setTimeout
Note: setTimeout and clearTimeout are not ECMAScript native methods, but Javascript methods of the global window namespace.
You will have to remember the timeout "Timer", cancel it, then restart it:
g_timer = null;
$(document).ready(function() {
startTimer();
});
function startTimer() {
g_timer = window.setTimeout(function() {
window.location.href = 'file.php';
}, 115000);
}
function onClick() {
clearTimeout(g_timer);
startTimer();
}
var myTimer = setTimeout(..., 115000);
something.click(function () {
clearTimeout(myTimer);
myTimer = setTimeout(..., 115000);
});
Something along those lines!
For NodeJS it's super simple:
const timeout = setTimeout(...);
timeout.refresh();
From the docs:
timeout.refresh()
Sets the timer's start time to the current time, and reschedules the timer to call its callback at the previously specified duration adjusted to the current time. This is useful for refreshing a timer without allocating a new JavaScript object.
But it won't work in JavaScript because in browser setTimeout() returns a number, not an object.
This timer will fire a "Hello" alertbox after 30 seconds. However, everytime you click the reset timer button it clears the timerHandle then re-sets it again. Once it's fired, the game ends.
<script type="text/javascript">
var timerHandle = setTimeout("alert('Hello')",3000);
function resetTimer() {
window.clearTimeout(timerHandle);
timerHandle = setTimeout("alert('Hello')",3000);
}
</script>
<body>
<button onclick="resetTimer()">Reset Timer</button>
</body>
var redirectionDelay;
function startRedirectionDelay(){
redirectionDelay = setTimeout(redirect, 115000);
}
function resetRedirectionDelay(){
clearTimeout(redirectionDelay);
}
function redirect(){
location.href = 'file.php';
}
// in your click >> fire those
resetRedirectionDelay();
startRedirectionDelay();
here is an elaborated example for what's really going on http://jsfiddle.net/ppjrnd2L/
i know this is an old thread but i came up with this today
var timer = []; //creates a empty array called timer to store timer instances
var afterTimer = function(timerName, interval, callback){
window.clearTimeout(timer[timerName]); //clear the named timer if exists
timer[timerName] = window.setTimeout(function(){ //creates a new named timer
callback(); //executes your callback code after timer finished
},interval); //sets the timer timer
}
and you invoke using
afterTimer('<timername>string', <interval in milliseconds>int, function(){
your code here
});
$(function() {
(function(){
var pthis = this;
this.mseg = 115000;
this.href = 'file.php'
this.setTimer = function() {
return (window.setTimeout( function() {window.location.href = this.href;}, this.mseg));
};
this.timer = pthis.setTimer();
this.clear = function(ref) { clearTimeout(ref.timer); ref.setTimer(); };
$(window.document).click( function(){pthis.clear.apply(pthis, [pthis])} );
})();
});
To reset the timer, you would need to set and clear out the timer variable
$time_out_handle = 0;
window.clearTimeout($time_out_handle);
$time_out_handle = window.setTimeout( function(){---}, 60000 );