JavaScript/jQuery clearInterval being set in .each - javascript

So I have an interval I create for each of my posts, the issue is that I load new posts and remove the old ones, so obviously I'd like to stop the interval for the previous posts. However I can't seem to figure out how to do this. Could someone explain to me how to properly go about doing this? I'm completely lost.
$(".post").each(function(){
myInterval = setInterval("postStats('"+$(this).attr('id')+"')", 500);
});
function postStats(pid) {
//do some stuff
}
$(".button").click(function(){
clearInterval(myInterval);
});

You can store the interval ID in a data attribute:
$(".post").each(function () {
var that = this;
var myInterval = setInterval(function () {
postStats(that.id);
}, 500);
$(this).data("i", myInterval);
});
and clear the interval specific to each .post like so:
$(".button").click(function () {
// assuming the button is inside a post
clearInterval($(this).closest(".post").data("i"));
});
and like SiGanteng said, you should pass a function object to setInterval rather than a string, which only gets eval'd.

You need to keep one handle for each interval that you start:
var myIntervals = [];
$(".post").each(function(){
var id = $(this).attr('id');
var handle = window.setInterval(function(){
postStats(id);
}, 500);
myIntervals.push(handle);
});
function postStats(pid) {
//do some stuff
}
$(".button").click(function(){
$.each(myIntervals, function(i, val){
window.clearInterval(val);
});
myIntervals = [];
});

Related

Removing class after X seconds?

I'm trying this below code:
$(document).ready(function() {
$("button").hover(
function() {
$(this).addClass("active");
},
function() {
$(this).removeClass("active");
}
);
});
Try this: http://plnkr.co/edit/Xlco44QPWvKEh1jb0gDf?p=preview
var button = $('button');
button.hover(
function() {
button.addClass('active');
setTimeout(function() {
button.removeClass('active');
}, 3000);
},
function() {
button.removeClass('active');
}
);
From what you said in your previous comment below, you tried setTimeout and it didn't work because of the the way you used this. The value of this inside the timeout function wasn't the same as in your outer function, so jQuery didn't match your button element.
Better to define the button once as a variable, and reuse the variable, that use repeated jQuery selectors.
UPDATE: Here's a slightly more sophisticated version that keeps the setTimeout timers from piling up:
$(function() {
var button = $('button');
var timeout = 0;
button.hover(
function() {
button.addClass('active');
timeout = setTimeout(function() {
button.removeClass('active');
timeout = 0;
}, 2000);
},
function() {
button.removeClass('active');
if (timeout) {
clearTimeout(timeout);
timeout = 0;
}
}
);
});
I have created a jQuery extention just for that! This is extremely common in web development:
jQuery.addTempClass.js
$.fn.addTempClass = function(tempClass, duration){
if( !tempClass )
return this;
return this.each(function(){
var $elm = $(this),
timer;
$elm.addClass(tempClass);
// clear any timeout, if was any
clearTimeout( $elm.data('timeout') )
timer = setTimeout(function(){
$elm.removeClass(tempClass).removeData('timeout');
}, duration || 100);
// set the timer on the element
$elm.data('timeout', timer);
});
};
Usage example:
$(document.body).addTempClass('some_class', 2000)
You can include this script as a dependency file for your build system or simply copy-paste this piece of code somewhere in your code, just after jQuery has loaded, so it will be available everywhere afterwards.

How to pass variable asyncronously through different scripts

I can't figure out how to do it.
I have two separate scripts. The first one generates an interval (or a timeout) to run a specified function every x seconds, i.e. reload the page.
The other script contains actions for a button to control (pause/play) this interval.
The pitfall here is that both sides must be asyncronous (both run when the document is loaded).
How could I properly use the interval within the second script?
Here's the jsFiddle: http://jsfiddle.net/hm2d6d6L/4/
And here's the code for a quick view:
var interval;
// main script
(function($){
$(function(){
var reload = function() {
console.log('reloading...');
};
// Create interval here to run reload() every time
});
})(jQuery);
// Another script, available for specific users
(function($){
$(function(){
var $playerButton = $('body').find('button.player'),
$icon = $playerButton.children('i');
buttonAction = function(e){
e.preventDefault();
if ($(this).hasClass('playing')) {
// Pause/clear interval here
$(this).removeClass('playing').addClass('paused');
$icon.removeClass('glyphicon-pause').addClass('glyphicon-play');
}
else {
// Play/recreate interval here
$(this).removeClass('paused').addClass('playing');
$icon.removeClass('glyphicon-play').addClass('glyphicon-pause');
}
},
buttonInit = function() {
$playerButton.on('click', buttonAction);
};
buttonInit();
});
})(jQuery);
You could just create a simple event bus. This is pretty easy to create with jQuery, since you already have it in there:
// somewhere globally accessible (script 1 works fine)
var bus = $({});
// script 1
setInterval(function() {
reload();
bus.trigger('reload');
}, 1000);
// script 2
bus.on('reload', function() {
// there was a reload in script 1, yay!
});
I've found a solution. I'm sure it's not the best one, but it works.
As you pointed out, I eventually needed at least one global variable to act as a join between both scripts, and the use of a closure to overcome asyncronous issues. Note that I manipulate the button within reload, just to remark that sometimes it's not as easy as moving code outside in the global namespace:
Check it out here in jsFiddle: yay! this works!
And here's the code:
var intervalControl;
// main script
(function($){
$(function(){
var $playerButton = $('body').find('button.player'),
reload = function() {
console.log('reloading...');
$playerButton.css('top', parseInt($playerButton.css('top')) + 1);
};
var interval = function(callback) {
var timer,
playing = false;
this.play = function() {
if (! playing) {
timer = setInterval(callback, 2000);
playing = true;
}
};
this.pause = function() {
if (playing) {
clearInterval(timer);
playing = false;
}
};
this.play();
return this;
};
intervalControl = function() {
var timer = interval(reload);
return {
play: function() {
timer.play();
},
pause: function(){
timer.pause();
}
}
}
});
})(jQuery);
// Another script, available for specific users
(function($){
$(function(){
var $playerButton = $('body').find('button.player'),
$icon = $playerButton.children('i'),
interval;
buttonAction = function(e){
e.preventDefault();
if ($(this).hasClass('playing')) {
interval.pause();
$(this).removeClass('playing').addClass('paused');
$icon.removeClass('glyphicon-pause').addClass('glyphicon-play');
}
else {
interval.play();
$(this).removeClass('paused').addClass('playing');
$icon.removeClass('glyphicon-play').addClass('glyphicon-pause');
}
},
buttonInit = function() {
$playerButton.on('click', buttonAction);
interval = intervalControl();
};
buttonInit();
});
})(jQuery);
Any better suggestion is most welcome.

Simulating Spinner Number with mousedown

I made a control (numeric spinner up and down), to work in a table:
JSFIDDLE: http://jsfiddle.net/Leandro1981/wn8vd/1/
and I want simulate the "mousedown, increment while mouse button is helding" but I can't do it. I tried to mix it with the following and functional script:
JSFIDDLE: http://jsfiddle.net/Leandro1981/kKW85/
but I couldn't make it.
My last attempt here:
http://jsfiddle.net/Leandro1981/S8Zt9/1/
Maybe the wrong is the
timeout = setInterval(function () {
But I couldn't figure out. I'm using bootstrap 3, so I can't use some JQuery UI plugins...
Any help will be preciated!
Please comment below if you have any question, comment or anything to improve this question, and sorry for my english :)
Please be free to use my code/control in any way.
Thanks and kind regards
Write a factory to set up each control so you get a closure over the variables, now it's just a matter of being able to make it work given the relevant elements. For this, you'll need to
Listen for mousedown on the up and down nodes to set off the changes
Start a timeout loop to keep doing your change
Listen for mouseup on window to ensure you cancel the timeout loop (you may also want to listen for mouseout/loss of focus)
So all together,
function spinFactory(node, up, down) { // I wrote this vanilla :D
var spinning, delta;
window.addEventListener('mouseup', stopSpin);
function spin() {
node.value = +node.value + delta;
spinning = setTimeout(spin, 500);
}
function stopSpin() { // maybe also invoke this on mouseout/loss of focus
window.clearTimeout(spinning);
delta = 0;
}
up.addEventListener('mousedown', function spinUp() {
delta = 1;
spin();
});
down.addEventListener('mousedown', function spinDown() {
delta = -1;
spin();
});
}
// apply to your control, used a bit of jQuery to make life easier
$('.PNET-spinner').each(function () {
spinFactory(
this.getElementsByTagName('input')[0],
$(this).find('.btn:first-of-type')[0],
$(this).find('.btn:last-of-type')[0]
);
});
DEMO
I have updated the Fiddle here ... Please check this and it might helps you..
Script
$('.PNET-spinner .btn:first-of-type').on('mousedown', function (e) {
var timer, proxy = this;
timer = setInterval(function () {
increment(proxy);
}, 200);
$(document).one("mouseup", function () {
increment(proxy);
if (timer) clearInterval(timer);
});
});
$('.PNET-spinner .btn:last-of-type').on('mousedown', function () {
var timer, proxy = this;
timer = setInterval(function () {
decrement(proxy);
}, 200);
$(document).one("mouseup", function () {
decrement(proxy);
if (timer) clearInterval(timer);
});
});
function increment(proxy) {
var numupdown = $('.PNET-spinner input', $(proxy).closest("tr"));
var inputValue = parseInt($(numupdown).val(), 10);
inputValue++;
$(numupdown).val(inputValue);
}
function decrement(proxy) {
var numupdown = $('.PNET-spinner input', $(proxy).closest("tr"));
var inputValue = parseInt($(numupdown).val(), 10);
if (inputValue > 1) {
inputValue--;
$(numupdown).val(inputValue);
}
}
You simply need to take care of two things. First, your function to increment and decrement the value in the textbox should be called again and again till user do mouseout or mouseup. Second, make surethis has the right value in var numupdown = $('.PNET-spinner input', $(this).closest("tr"));
Following code shows how to do it for the increment button. Similar thing, you can implement for decrement button.
var timeout;
var inc = function () {
var myThis = this;
var numupdown = $('.PNET-spinner input', $(this).closest("tr"));
var inputValue = parseInt($(numupdown).val(), 10);
inputValue++;
console.log(inputValue);
$(numupdown).val(inputValue);
clearTimeout(timeout);
timeout = setTimeout(function(){
//http://stackoverflow.com/questions/3630054/how-do-i-pass-the-this-context-to-a-function
inc.apply(myThis, arguments);
}, 1000);
};
var incStop = function(){
clearTimeout(timeout);
}
$('.PNET-spinner .btn:first-of-type').on('mousedown', inc);
$('.PNET-spinner .btn:first-of-type').on('mouseup', incStop);
$('.PNET-spinner .btn:first-of-type').on('mouseout', incStop);
Check this DEMO here.

Incrementing a setInterval() value from a global

I'm trying to increment the timeout on either setInterval, or setTimout. However, my global is not working. I'm not to familiar with javascript. Please help!
//What I'm trying to do:
$(document).ready(function() {
var joeIncrement=1;
setInterval(function() {
joeIncrement++;
$('#comment_counter').load('get_commentcount.php');
}, 15000*joeIncrement);
});
$(document).ready(function() {
var joeIncrement=1;
var interval = function(){
setTimeout(function() {
joeIncrement++;
$('#comment_counter').load('get_commentcount.php');
interval();
}, 15000*joeIncrement);
}
interval(joeIncrement)
});

Repeat code every x seconds but not if [insert check here]

This is a followup to this question, where I found out how to make code be repeated every x seconds. Is it possible to make an event that can change this? I.e. I have a checkbox which is meant to control whether this is repeated or not, so I figured I'd need something like this:
$(checkbox).bind("change", function() {
switch(whether if it is ticked or not) {
case [ticked]:
// Make the code repeat, while preserving the ability to stop it repeating
case [unticked]:
// Make the code stop repeating, while preserving the ability to start again
}
});
I have no idea what I could put in the cases.
You can do it by assigning your setInterval function to a variable.
var interval = setInterval(function() { }, 1000);
and then you can stop setInterval by
clearInterval(interval);
p.s.
to start your interval you need to call var interval = setInterval(function() { }, 1000); again
You can either stop and start the interval:
var timer;
function start() {
timer = window.setInterval(function(){
// do something
}, 1000);
}
function stop() {
window.clearInterval(timer);
}
start();
$(checkbox).bind("change", function() {
if ($(this).is(':checked')) {
start();
} else {
stop();
}
});
Or you can have a flag causing the interval to skip the code:
var enabled = true;
var timer = window.setInterval(function(){
if (!enabled) {
// do something
}
}, 1000);
$(checkbox).bind("change", function() {
enabled = $(this).is(':checked');
});
function fooFunc() {
$('#foo').text(+new Date());
}
var id;
var shouldBeStopped = false;
$('input').change(function() {
if (shouldBeStopped)
clearInterval(id);
else
id = setInterval(fooFunc, 200);
shouldBeStopped = !shouldBeStopped;
});​
Live DEMO

Categories