Develop Reference

How to use jquery resize run funtion one time?

I want to use run 2 functions jquery when resize window. But I just want to do they one time. code can be like:
jQuery(document).ready(function () {
var screenwidth=jQuery(window).width();
if(screenwidth>991){
dofunction1();
}
else{
dofunction2();
}
});
I want when screenwidth>991 do dofunction1() 1 time, and when screenwidth<=991 do dofunction2() 1 time. Hope your help!!

You can use .one() to bind resize event
Attach a handler to an event for the elements. The handler is executed at most once per element per event type.
$(window).one('resize', function () {
var screenwidth = jQuery(window).width();
if (screenwidth > 991) {
dofunction1();
} else {
dofunction2();
}
});

Dynamically add class on browser resize (viewport width)

I have an element called jobfilter, which I want to add a class to depending on the viewport width, ie. when I resize my browser to <1000px, I want to add the class .hidden to .jobfilter.
Now, I managed to get it half-working with the help of this link: $(window).width() not the same as media query.
Using this:
function checkPosition() {
if (window.matchMedia('(max-width: 767px)').matches) {
//...
} else {
//...
}
}
Here's my JSFiddle: http://jsfiddle.net/ck55Lf01/10/.
If you resize the browser and refresh the page, the jobfilter hides, but I'd like that to happen dynamically, not on the refresh of the page, thank you for your help!

This is a fucnction I use to dynamically check the window width on resize, I wrapped it in a document ready function that passes the $ as a parameter to prevent any conflicts that might occur with other javascript libraries that use the $. An example would be if you were to use your function inside of a wordpress theme or plugin.
Jsfiddle example: http://jsfiddle.net/larryjoelane/ck55Lf01/24/
Javascript:
/*
document ready function used to prevent conflict with other javascript libraries
that use the $ parameter
*/
jQuery(document).ready(function($){
//get the window width
var winWidth = $(window).width();
//set the maxWidth
var maxWidth = 1000;
//if the window width is less than the maxWidth pixels on document loading
if(winWidth < maxWidth){//begin if then
//add the class hidden to .jobFilter
$(".jobfilter").addClass("hidden");
}//end if then
$(window).resize(function(){//begin resize event
//get the window width
var winWidth = $(window).width();
//set the maxWidth
var maxWidth = 1000;
//if the window width is less than maxWidth pixels
if(winWidth < maxWidth){//begin if then
//add the class hidden to .jobFilter
$(".jobfilter").addClass("hidden");
}
else{
//remove the class hidden
$(".jobfilter").removeClass("hidden");
}//end if then else
});//end window resize event
});//end document ready function

Update August 2021
It's still a little-known fact that matchMedia has an event listener. It triggers a "change" event whenever it changes. You can use that to toggle a class depending on whether or not it matches, and listen for that match changing without having to bind anything to the (potentially heavy) window resize event.
function doSomething(matches) {
if (matches) {
// media query matches
} else {
// media query does not match
}
}
const query = window.matchMedia("(max-width: 767px)");
query.addEventListener("change", ({ matches }) => doSomething(matches));
doSomething(query.matches);
This is also mentioned on MDN.
Original Answer
Little known fact: matchMedia has an event listener:
function handleMedia(mql) {
if (mql.matches) {
// media query matches
} else {
// media query does not match
}
}
var mql = window.matchMedia('(max-width: 767px)').addListener(handleMedia);
handleMedia(mql);
The event listener will execute every time the browser matches or unmatches the media query. In your case, I'd recommend firing the handler manually as well (as shown in the example) to be sure to get the correct class set on load.
This example is taken from MDN (although it's pretty well hidden).

you have to listen on the resize event.
$( window ).resize(function() {
checkPosition();
});

Use the resize event to check if the window is resized or not. Use this code
$( window ).resize(function() {
function checkPosition() {
if (window.matchMedia('(max-width: 767px)').matches) {
//...
} else {
//...
}
}
}
Hope this helps you

$(document).ready(function(){
DOaction(); // run function after document ready
$(window).on('resize',DOaction); // on resize window run function
});
// function to add and remove hidden class
function DOaction(){
if($(window).width() <= 1000){
$(".jobfilter").addClass('hidden');
}else{
$(".jobfilter").removeClass('hidden');
}
}
Jsfiddle

Trigger jQuery mousemove event only once

I'm trying to make an exit popup and I could do that using the following code.
Whenever the user's mouse move out of the browser area, this gives a popup. But it is quite annoying when the popup comes everytime. I want to limit it to just a single time.
Can somebody help me with this?
jQuery(document).ready(function () {
jQuery(document).mousemove(function(e) {
jQuery('#exitpopup').css('left', (window.innerWidth/2 - jQuery('#exitpopup').width()/2));
jQuery('#exitpopup').css('top', (window.innerHeight/2 - jQuery('#exitpopup').height()/2));
if(e.pageY <= 5)
{
// Show the exit popup
jQuery('#exitpopup_bg').fadeIn();
jQuery('#exitpopup').fadeIn();
}
});
});

Use jQuery's one() function: http://api.jquery.com/one/
jQuery(document).ready(function () {
jQuery(document).one('mousemove', function(e) {
jQuery('#exitpopup').css('left', (window.innerWidth/2 - jQuery('#exitpopup').width()/2));
jQuery('#exitpopup').css('top', (window.innerHeight/2 - jQuery('#exitpopup').height()/2));
if(e.pageY <= 5)
{
// Show the exit popup
jQuery('#exitpopup_bg').fadeIn();
jQuery('#exitpopup').fadeIn();
}
});
});

Insert this:
e.stopPropagation();
just at the first list of the mousemouve function.
....
jQuery(document).mousemove(function(e) {
e.stopPropagation();
jQuery('#exitpopup').css('left', (window.innerWidth/2 - jQuery('#exitpopup').width()/2));
...

(function($) {
$(document).ready(function () {
var leftPage = false;
$(document).mousemove(function(e) {
if(e.pageY <= 5)
{
if (!leftPage) {
var exitPopup = $('#exitpopup');
exitPopup.css('left', (window.innerWidth/2 - exitPopup.width()/2));
exitPopup.css('top', (window.innerHeight/2 - exitPopup.height()/2));
$('#exitpopup_bg').fadeIn();
exitPopup.fadeIn();
}
leftPage = true;
} else {
leftPage = false;
}
});
});
})(jQuery);
"If the user leaves the page AND they have not already left THEN set popup. Next mark that they have left the page (leftPage = true)"
"Do not try and set the popup again until they are back in the page"
Couple of extras:
Instead of calling jQuery all the time we wrap the whole thing in a function wrapper so you can use $.
Instead of doing this everytime $('#exitpopup'); we CACHE it to a variable exitPopup so it doesn't have to do the lookup every time (inefficient)

A few things here. First, for form's sake, you should move your CSS alterations inside the if block, because you really don't need those to run every time the user moves their mouse, just right before you show the popup:
if(e.pageY <= 5)
{
// Alter CSS as appropriate
jQuery('#exitpopup').css('left', (window.innerWidth/2 - jQuery('#exitpopup').width()/2));
jQuery('#exitpopup').css('top', (window.innerHeight/2 - jQuery('#exitpopup').height()/2));
// Show the exit popup
jQuery('#exitpopup_bg').fadeIn();
jQuery('#exitpopup').fadeIn();
}
Second, you'll probably want to avoid showing it a second time by detaching the event handler. I'd recommend you use the jQuery .on() and .off() syntax instead of the shorthand .mousemove() because it'll be easier to read and maintain. I also recommend you use namespaces on your events so you can ensure that you're not detaching events that might have been set in other scripts.
jQuery(document).on('mousemove.yourNamespace', function (e) {
if(e.pageY <= 5)
{
// Alter CSS as appropriate
jQuery('#exitpopup').css('left', (window.innerWidth/2 - jQuery('#exitpopup').width()/2));
jQuery('#exitpopup').css('top', (window.innerHeight/2 - jQuery('#exitpopup').height()/2));
// Show the exit popup
jQuery('#exitpopup_bg').fadeIn();
jQuery('#exitpopup').fadeIn();
// now detach the event handler so it won't fire again
jQuery(document).off('mousemove.yourNamespace');
}
}
Lastly, if you wrap all of this code in an IIFE, you won't have to write out jQuery every time, and you still won't have to worry about possible conflicts with $ in the global namespace.
(function ($) {
$(document).on('mousemove.yourNamespace', function (e) {
if(e.pageY <= 5)
{
// Alter CSS as appropriate
$('#exitpopup').css('left', (window.innerWidth/2 - $('#exitpopup').width()/2));
$('#exitpopup').css('top', (window.innerHeight/2 - $('#exitpopup').height()/2));
// Show the exit popup
$('#exitpopup_bg').fadeIn();
$('#exitpopup').fadeIn();
// now detach the event handler so it won't fire again
$(document).off('mousemove.yourNamespace');
}
}
})(jQuery);
jQuery docs for .on(), .off(), and event.namespace for reference.

Differentiate between focus event triggered by keyboard/mouse

I'm using jquery ui autocomplete and want to decipher between focus events triggered by keyboard interaction and mouse interaction. How would I go about this?
$('input').autocomplete({
source: function(request, response) {
...
},
focus: function(event, ui) {
// If focus triggered by keyboard interaction
alert('do something');
// If focus event triggered by mouse interaction
alert('do something else');
}
});
Thanks

The only way I can think of doing this is to have a handler listen in on the keypress and click events, and toggle a boolean flag on/off. Then on the focus handler of your input, you can just check what the value of your flag is, and go from there.
Probably something like
var isClick;
$(document).bind('click', function() { isClick = true; })
.bind('keypress', function() { isClick = false; })
;
var focusHandler = function () {
if (isClick) {
// clicky!
} else {
// tabby!
}
}
$('input').focus(function() {
// we set a small timeout to let the click / keypress event to trigger
// and update our boolean
setTimeout(focusHandler,100);
});
Whipped up a small working prototype on jsFiddle (don't you just love this site?). Check it out if you want.
Of course, this is all running off a focus event on an <input>, but the focus handler on the autocomplete works in the same way.
The setTimeout will introduce a bit of lag, but at 100ms, it might be negligible, based on your needs.

You should actually be able to determine this from the event-Object that is passed into the focus-event. Depending on your code structure this might be different, but there is usually a property called originalEvent in there, which might be nested to some depth. Examine the event-object more closely to determine the correct syntax. Then test on mousenter or keydown via regular expression. Something like this:
focus: function(event, ui){
if(/^key/.test(event.originalEvent.originalEvent.type)){
//code for keydown
}else{
//code for mouseenter and any other event
}
}

The easiest and most elegant way I've found of achieving this is to use the "What Input?" library. It's tiny (~2K minified), and gives you access to the event type both in scripts:
if (whatInput.ask() === 'mouse') {
// do something
}
...and also (via a single data attribute that it adds to the document body) styles:
[data-whatinput="mouse"] :focus,
[data-whatinput="touch"] :focus {
// focus styles for mouse and touch only
}
I particularly like the fact that where you just want a different visual behaviour for mouse / keyboard it makes it possible to do that in the stylesheet (where it really belongs) rather than via some hacky bit of event-checking Javascript (though of course if you do need to do something that's not just purely visual, the former approach lets you handle it in Javascript instead).

The first thing that comes to mind is that you can find the position of the mouse and check to see if its within the position of the element
Use this to store the position of the element:
var input = $('#your_autocompleted_element_id'),
offset = input.offset(),
input_x = offset.top,
input_y = offset.left,
input_w = input.outerWidth(),
input_h = input.outerHeight();
Then use this to find absolute position of the mouse within the window:
var cur_mx, cur_my;
$(document).mousemove(function(e){
cur_mx = e.pageX;
cur_my = e.pageY;
});
Then in your autcomplete setup:
focus: function(event, ui) {
// mouse is doing the focus when...
// mouse x is greater than input x and less than input x + input width
// and y is greater than input y and less than input y + input height
if (cur_mx >= input_x && cur_mx <= input_x + input_w && cur_my >= input_y && cur_my <= input_y + input_h) {
// do your silly mouse focus witchcraft here
} else {
// keyboard time!
}
}

This can be handled using mousedown event, see my example below.
this.focusFrom = 'keyboard' =>
onFocus = () => {
if (this.focusFrom === 'keyboard') {
// do something when focus from keyboard
}
}
handleMouseDown = () => {
this.focusFrom = 'mouse';
}
handleOnClick = () => {
this.focusFrom = 'keyboard';
}

Prevent click event in jQuery triggering multiple times

I have created a jQuery content switcher. Generally, it works fine, but there is one problem with it. If you click the links on the side multiple times, multiple pieces of content sometimes become visible.
The problem most likely lies somewhere within the click event. Here is the code:
$('#tab-list li a').click(
function() {
var targetTab = $(this).attr('href');
if ($(targetTab).is(':hidden')) {
$('#tab-list li').removeClass('selected');
var targetTabLink = $(this).parents('li').eq(0);
$(targetTabLink).addClass('selected');
$('.tab:visible').fadeOut('slow',
function() {
$(targetTab).fadeIn('slow');
}
);
}
return false;
}
);
I have tried adding a lock to the transition so that further clicks are ignored as the transition is happening, but to no avail. I have also tried to prevent the transition from being triggered if something is already animating, using the following:
if ($(':animated')) {
// Don't do anything
}
else {
// Do transition
}
But it seems to always think things are being animated. Any ideas how I can prevent the animation being triggered multiple times?

One idea would be to remove the click event at the start of your function, and then add the click event back in when your animation has finished, so clicks during the duration would have no effect.
If you have the ability to execute code when the animation has finished this should work.

Add a variable to use as a lock rather than is(:animating).
On the click, check if the lock is set. If not, set the lock, start the process, then release the lock when the fadeIn finishes.
var blockAnimation = false;
$('#tab-list li a').click(
function() {
if(blockAnimation != true){
blockAnimation = true;
var targetTab = $(this).attr('href');
if ($(targetTab).is(':hidden')) {
$('#tab-list li').removeClass('selected');
var targetTabLink = $(this).parents('li').eq(0);
$(targetTabLink).addClass('selected');
$('.tab:visible').fadeOut('slow',
function() {
$(targetTab).fadeIn('slow', function(){ blockAnimation=false; });
}
);
}
}
return false;
}
);

Well this is how i did it, and it worked fine.
$(document).ready(function() {
$(".clickitey").click(function () {
if($("#mdpane:animated").length == 0) {
$("#mdpane").slideToggle("slow");
$(".jcrtarrow").toggleClass("arrow-open");
}
});
});
this is not doing what your code does ofcourse this is a code from my site, but i just like to point how i ignored the clicks that were happening during the animation. Please let me know if this is inefficient in anyway. Thank you.

I toyed around with the code earlier and came up with the following modification which seems to work:
$('#tab-list li a').click(
function() {
$('.tab:animated').stop(true, true);
var targetTab = $(this).attr('href');
if ($(targetTab).is(':hidden')) {
$('#tab-list li').removeClass('selected');
var targetTabLink = $(this).parents('li').eq(0);
$(targetTabLink).addClass('selected');
$('.tab:visible').fadeOut('slow',
function() {
$(targetTab).fadeIn('slow');
}
);
}
return false;
}
);
All that happens is, when a new tab is clicked, it immediately brings the current animation to the end and then begins the new transition.

one way would be this:
$('#tab-list ul li').one( 'click', loadPage );
var loadPage = function(event) {
var $this = $(this);
$global_just_clicked = $this;
var urlToLoad = $this.attr('href');
$('#content-area').load( urlToLoad, pageLoaded );
}
$global_just_clicked = null;
var pageLoaded() {
$global_just_clicked.one( 'click', loadPage );
}
As you can see, this method is fraught with shortcomings: what happens when another tab is clicked before the current page loads? What if the request is denied? what if its a full moon?
The answer is: this method is just a rudimentary demonstration. A proper implementation would:
not contain the global variable $global_just_clicked
not rely on .load(). Would use .ajax(), and handle request cancellation, clicking of other tabs etc.
NOTE: In most cases you need not take this round-about approach. I'm sure you can remedy you code in such a way that multiple clicks to the same tab would not affect the end result.
jrh.

One way to do this to use timeStamp property of event like this to gap some time between multiple clicks:
var a = $("a"),
stopClick = 0;
a.on("click", function(e) {
if(e.timeStamp - stopClick > 300) { // give 300ms gap between clicks
// logic here
stopClick = e.timeStamp; // new timestamp given
}
});