I have the following script that runs on page load. It's meant to observe every td element on the page and check if it changes.
I was just logging the mutation to console to see my next steps, as I want to see what values change in each td element (the div refreshes every 15 seconds that houses the table).
Here's what I've got so far:
jQuery(document).ready(function( $ ) {
/** Change URL */
setInterval(function() {
$.ajax({
url: 'http://localhost:8888/profitmanager/wp-content/plugins/football-stats/update.php'
}).done(function(){
$('.fbs_results').load(
location.href+" .fbs_results>*", function(){
var hidden = [];
$.each(JSON.parse(localStorage.getItem("table_state")), function(index, value) {
if(value == 'hidden'){
$('tr[data-index="'+index+'"]').hide();
}
});
// console.log(hidden);
$('tr').each(function(index){
});
}
);
});
}, 15000);
const config = {
characterData: true,
characterDataOldValue: true,
childList: true,
subtree: true
};
function tdChanges(mutations) {
mutations.forEach((mutation) => {
console.log(mutation);
// if (mutation.addedNodes.value) {
// console.log();
// }
});
}
const tds = document.querySelectorAll('td');
Array.from(tds).forEach(function(td) {
const observer = new MutationObserver(tdChanges);
observer.observe(td, config);
});
});
But it doesn't work, nothing logs. Weird.
Can anyone fix my code?
TIA
querySelector() returns only a single Element. To look at all of them you need to use querySelectorAll() then loop over the result:
const tds = document.querySelectorAll('td');
Array.from(tds).forEach(function(td) {
const observer = new MutationObserver(tdChanges);
observer.observe(td, config);
});
Here's a working example in a jsFiddle, as the SO snippet editor is sandboxed and has issues running MutationObservers.
One thing to note here is that MutationObservers are not fast, and if you have a lot of td elements in your page you may see a performance hit. You may be better served by placing a single MutationObserver on the parent table and letting the event bubble up, like this.
I have jQuery replaceWith call, and I want to pop up an alert only when the replaceWith finishes loading.
To achieve this I have this very naive javascript implementation:
$(document).ready(function (){
$("#myDiv").click(function () {
$("#myDiv").replaceWith("<div>Hello World!!!</div>");
alert("done");
});
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div id="myDiv">Hello!</div>
The problem is that in this case the alert will pop-up independently of the time that the replaceWith takes. If it is fast, no problem, but if the replaceWith takes several seconds to load (which is the real case) then the pop-up appears way before, and I want to avoid that.
How can I achieve the behaviour I am looking for?
Try
$(document).ready(function() {
var body = $("body");
$("#myDiv").click(function(e) {
var html = $("<div>Hello World!!!</div>");
$("#myDiv").replaceWith(html)
.promise().done(function(elem) {
if (body.find(html).is("*")
&& !body.find(elem).is("*")) {
alert("done");
}
});
});
});
$(document).ready(function() {
var body = $("body");
$("#myDiv").click(function(e) {
var html = $("<img src=http://lorempixel.com/output/cats-q-c-1920-1920-2.jpg />");
// $("<div>Hello World!!!</div>");
$("#myDiv").replaceWith(html)
.promise().done(function(elem) {
if (body.find(html).is("*")
&& !body.find(elem).is("*")) {
alert("done");
}
});
});
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div id="myDiv">Hello!</div>
I would try getting the value of what you're replacing - then check if it exists after the replacement - then you can alert its complete.
fiddle:
http://jsfiddle.net/eavxkc3f/
jquery:
$(document).ready(function (){
$(".myDiv").click(function () {
var currentItem = $(".myDiv").html();
var replacer = "<div>Hello World!!!</div>";
$(".myDiv").replaceWith("<div>Hello World!!!</div>");
if($(".myDiv").html != currentItem){
alert("Done.");
}
});
});
Take a look at the DOM MutationObserver spec, I think it does what you want. Register it on a target node, and it will watch for changes beneath that target.
It's an updated version of the now deprecated Mutation events
A blog post with additional good info (and where I found this sample code)
Working example in this fiddle (code below)
$(document).ready(function (){
$("#myDiv").click(function () {
$("#myDiv").replaceWith("<div>Hello World!!!</div>");
});
});
// select the target node
var target = document.querySelector('#divParent');
// create an observer instance
var observer = new MutationObserver(function(mutations) {
mutations.forEach(function(mutation) {
//console.log(mutation.type);
alert('Done');
});
});
// configuration of the observer:
var config = { attributes: true, childList: true, characterData: true };
// pass in the target node, as well as the observer options
observer.observe(target, config);
// later, you can stop observing
//observer.disconnect();
I'm trying to listen for a node with a certain class being added to the DOM dynamically. Once this Node has been added i want to then add an instance of of a plugin to this Node. The problem I'm having is DOMNodeInserted is running multiple times which is then running my plugin multiple on this one Node which is causing problems.
There is only ever one occurrence of this class on page.
Why is this and how can I stop this from happening?
$(document).ready(function(){
$('#editArea').live('DOMNodeInserted', '.class', function(e){
$('.class').plugin({
source: 'libs/ajax/somescript.php',
});
})
});
I ran into the same problem awhile back. What you need to do is debounce the function so it fires after the last DOMNodeInserted call.
Try this (adapted from John Hann's smartresize--comment/link left in):
(function ($, sr) {
// debouncing function from John Hann
// http://unscriptable.com/index.php/2009/03/20/debouncing-javascript-methods/
var debounce = function (func, threshold, execAsap) {
var timeout;
return function debounced() {
var obj = this, args = arguments;
function delayed() {
if (!execAsap)
func.apply(obj, args);
timeout = null;
};
if (timeout) {clearTimeout(timeout);
} else if (execAsap) {func.apply(obj, args);}
timeout = setTimeout(delayed, threshold || 100);
};
}
jQuery.fn[sr] = function (fn) { return fn ? this.on('DOMNodeInserted', debounce(fn)) : this.trigger(sr); };
})(jQuery, 'debouncedDNI');
$(document).ready(function () {
$('#editArea').debouncedDNI(function () {
$('.class').plugin({
source: 'libs/ajax/somescript.php',
});
});
});
Probably because in your DOM whatever the element you're watching for has children elements. The event is fired once for the matching element (.class) and once for each descendant.
If your element you need to watch is something like a select with a bunch of option elements under it, a quick and dirty solution might be to watch for another "buddy" element you can put along with it in the DOM. For instance:
$(document).ready(function(){
$('#editArea').on('DOMNodeInserted', '#classbuddy', function(e){
$('.class').plugin({
source: 'libs/ajax/somescript.php',
});
})
});
Then in your markup you would just need to add something like an empty span element with id="classbuddy". Because that span would not have children elements, your code would fire only once and so .plugin() would be applied one time only.
I'm using jQuery in my site and I would like to trigger certain actions when a certain div is made visible.
Is it possible to attach some sort of "isvisible" event handler to arbitrary divs and have certain code run when they the div is made visible?
I would like something like the following pseudocode:
$(function() {
$('#contentDiv').isvisible(function() {
alert("do something");
});
});
The alert("do something") code should not fire until the contentDiv is actually made visible.
Thanks.
You could always add to the original .show() method so you don't have to trigger events every time you show something or if you need it to work with legacy code:
Jquery extension:
jQuery(function($) {
var _oldShow = $.fn.show;
$.fn.show = function(speed, oldCallback) {
return $(this).each(function() {
var obj = $(this),
newCallback = function() {
if ($.isFunction(oldCallback)) {
oldCallback.apply(obj);
}
obj.trigger('afterShow');
};
// you can trigger a before show if you want
obj.trigger('beforeShow');
// now use the old function to show the element passing the new callback
_oldShow.apply(obj, [speed, newCallback]);
});
}
});
Usage example:
jQuery(function($) {
$('#test')
.bind('beforeShow', function() {
alert('beforeShow');
})
.bind('afterShow', function() {
alert('afterShow');
})
.show(1000, function() {
alert('in show callback');
})
.show();
});
This effectively lets you do something beforeShow and afterShow while still executing the normal behavior of the original .show() method.
You could also create another method so you don't have to override the original .show() method.
The problem is being addressed by DOM mutation observers. They allow you to bind an observer (a function) to events of changing content, text or attributes of dom elements.
With the release of IE11, all major browsers support this feature, check http://caniuse.com/mutationobserver
The example code is a follows:
$(function() {
$('#show').click(function() {
$('#testdiv').show();
});
var observer = new MutationObserver(function(mutations) {
alert('Attributes changed!');
});
var target = document.querySelector('#testdiv');
observer.observe(target, {
attributes: true
});
});
<div id="testdiv" style="display:none;">hidden</div>
<button id="show">Show hidden div</button>
<script type="text/javascript" src="https://code.jquery.com/jquery-1.9.1.min.js"></script>
There is no native event you can hook into for this however you can trigger an event from your script after you have made the div visible using the .trigger function
e.g
//declare event to run when div is visible
function isVisible(){
//do something
}
//hookup the event
$('#someDivId').bind('isVisible', isVisible);
//show div and trigger custom event in callback when div is visible
$('#someDivId').show('slow', function(){
$(this).trigger('isVisible');
});
You can use jQuery's Live Query plugin.
And write code as follows:
$('#contentDiv:visible').livequery(function() {
alert("do something");
});
Then everytime the contentDiv is visible, "do something" will be alerted!
redsquare's solution is the right answer.
But as an IN-THEORY solution you can write a function which is selecting the elements classed by .visibilityCheck (not all visible elements) and check their visibility property value; if true then do something.
Afterward, the function should be performed periodically using the setInterval() function. You can stop the timer using the clearInterval() upon successful call-out.
Here's an example:
function foo() {
$('.visibilityCheck').each(function() {
if ($(this).is(':visible')){
// do something
}
});
}
window.setInterval(foo, 100);
You can also perform some performance improvements on it, however, the solution is basically absurd to be used in action. So...
The following code (pulled from http://maximeparmentier.com/2012/11/06/bind-show-hide-events-with-jquery/) will enable you to use $('#someDiv').on('show', someFunc);.
(function ($) {
$.each(['show', 'hide'], function (i, ev) {
var el = $.fn[ev];
$.fn[ev] = function () {
this.trigger(ev);
return el.apply(this, arguments);
};
});
})(jQuery);
If you want to trigger the event on all elements (and child elements) that are actually made visible, by $.show, toggle, toggleClass, addClass, or removeClass:
$.each(["show", "toggle", "toggleClass", "addClass", "removeClass"], function(){
var _oldFn = $.fn[this];
$.fn[this] = function(){
var hidden = this.find(":hidden").add(this.filter(":hidden"));
var result = _oldFn.apply(this, arguments);
hidden.filter(":visible").each(function(){
$(this).triggerHandler("show"); //No bubbling
});
return result;
}
});
And now your element:
$("#myLazyUl").bind("show", function(){
alert(this);
});
You could add overrides to additional jQuery functions by adding them to the array at the top (like "attr")
a hide/show event trigger based on Glenns ideea:
removed toggle because it fires show/hide and we don't want 2fires for one event
$(function(){
$.each(["show","hide", "toggleClass", "addClass", "removeClass"], function(){
var _oldFn = $.fn[this];
$.fn[this] = function(){
var hidden = this.find(":hidden").add(this.filter(":hidden"));
var visible = this.find(":visible").add(this.filter(":visible"));
var result = _oldFn.apply(this, arguments);
hidden.filter(":visible").each(function(){
$(this).triggerHandler("show");
});
visible.filter(":hidden").each(function(){
$(this).triggerHandler("hide");
});
return result;
}
});
});
I had this same problem and created a jQuery plugin to solve it for our site.
https://github.com/shaunbowe/jquery.visibilityChanged
Here is how you would use it based on your example:
$('#contentDiv').visibilityChanged(function(element, visible) {
alert("do something");
});
What helped me here is recent ResizeObserver spec polyfill:
const divEl = $('#section60');
const ro = new ResizeObserver(() => {
if (divEl.is(':visible')) {
console.log("it's visible now!");
}
});
ro.observe(divEl[0]);
Note that it's crossbrowser and performant (no polling).
Just bind a trigger with the selector and put the code into the trigger event:
jQuery(function() {
jQuery("#contentDiv:hidden").show().trigger('show');
jQuery('#contentDiv').on('show', function() {
console.log('#contentDiv is now visible');
// your code here
});
});
Use jQuery Waypoints :
$('#contentDiv').waypoint(function() {
alert('do something');
});
Other examples on the site of jQuery Waypoints.
I did a simple setinterval function to achieve this. If element with class div1 is visible, it sets div2 to be visible. I know not a good method, but a simple fix.
setInterval(function(){
if($('.div1').is(':visible')){
$('.div2').show();
}
else {
$('.div2').hide();
}
}, 100);
You can also try jQuery appear plugin as mentioned in parallel thread https://stackoverflow.com/a/3535028/741782
This support easing and trigger event after animation done! [tested on jQuery 2.2.4]
(function ($) {
$.each(['show', 'hide', 'fadeOut', 'fadeIn'], function (i, ev) {
var el = $.fn[ev];
$.fn[ev] = function () {
var result = el.apply(this, arguments);
var _self=this;
result.promise().done(function () {
_self.triggerHandler(ev, [result]);
//console.log(_self);
});
return result;
};
});
})(jQuery);
Inspired By http://viralpatel.net/blogs/jquery-trigger-custom-event-show-hide-element/
There is a jQuery plugin available for watching change in DOM attributes,
https://github.com/darcyclarke/jQuery-Watch-Plugin
The plugin wraps All you need do is bind MutationObserver
You can then use it to watch the div using:
$("#selector").watch('css', function() {
console.log("Visibility: " + this.style.display == 'none'?'hidden':'shown'));
//or any random events
});
Hope this will do the job in simplest manner:
$("#myID").on('show').trigger('displayShow');
$('#myID').off('displayShow').on('displayShow', function(e) {
console.log('This event will be triggered when myID will be visible');
});
I changed the hide/show event trigger from Catalint based on Glenns idea.
My problem was that I have a modular application. I change between modules showing and hiding divs parents. Then when I hide a module and show another one, with his method I have a visible delay when I change between modules. I only need sometimes to liten this event, and in some special childs. So I decided to notify only the childs with the class "displayObserver"
$.each(["show", "hide", "toggleClass", "addClass", "removeClass"], function () {
var _oldFn = $.fn[this];
$.fn[this] = function () {
var hidden = this.find(".displayObserver:hidden").add(this.filter(":hidden"));
var visible = this.find(".displayObserver:visible").add(this.filter(":visible"));
var result = _oldFn.apply(this, arguments);
hidden.filter(":visible").each(function () {
$(this).triggerHandler("show");
});
visible.filter(":hidden").each(function () {
$(this).triggerHandler("hide");
});
return result;
}
});
Then when a child wants to listen for "show" or "hide" event I have to add him the class "displayObserver", and when It does not want to continue listen it, I remove him the class
bindDisplayEvent: function () {
$("#child1").addClass("displayObserver");
$("#child1").off("show", this.onParentShow);
$("#child1").on("show", this.onParentShow);
},
bindDisplayEvent: function () {
$("#child1").removeClass("displayObserver");
$("#child1").off("show", this.onParentShow);
},
I wish help
One way to do this.
Works only on visibility changes that are made by css class change, but can be extended to watch for attribute changes too.
var observer = new MutationObserver(function(mutations) {
var clone = $(mutations[0].target).clone();
clone.removeClass();
for(var i = 0; i < mutations.length; i++){
clone.addClass(mutations[i].oldValue);
}
$(document.body).append(clone);
var cloneVisibility = $(clone).is(":visible");
$(clone).remove();
if (cloneVisibility != $(mutations[0].target).is(":visible")){
var visibilityChangedEvent = document.createEvent('Event');
visibilityChangedEvent.initEvent('visibilityChanged', true, true);
mutations[0].target.dispatchEvent(visibilityChangedEvent);
}
});
var targets = $('.ui-collapsible-content');
$.each(targets, function(i,target){
target.addEventListener('visibilityChanged',VisbilityChanedEventHandler});
target.addEventListener('DOMNodeRemovedFromDocument',VisbilityChanedEventHandler });
observer.observe(target, { attributes: true, attributeFilter : ['class'], childList: false, attributeOldValue: true });
});
function VisbilityChanedEventHandler(e){console.log('Kaboom babe'); console.log(e.target); }
my solution:
; (function ($) {
$.each([ "toggle", "show", "hide" ], function( i, name ) {
var cssFn = $.fn[ name ];
$.fn[ name ] = function( speed, easing, callback ) {
if(speed == null || typeof speed === "boolean"){
var ret=cssFn.apply( this, arguments )
$.fn.triggerVisibleEvent.apply(this,arguments)
return ret
}else{
var that=this
var new_callback=function(){
callback.call(this)
$.fn.triggerVisibleEvent.apply(that,arguments)
}
var ret=this.animate( genFx( name, true ), speed, easing, new_callback )
return ret
}
};
});
$.fn.triggerVisibleEvent=function(){
this.each(function(){
if($(this).is(':visible')){
$(this).trigger('visible')
$(this).find('[data-trigger-visible-event]').triggerVisibleEvent()
}
})
}
})(jQuery);
example usage:
if(!$info_center.is(':visible')){
$info_center.attr('data-trigger-visible-event','true').one('visible',processMoreLessButton)
}else{
processMoreLessButton()
}
function processMoreLessButton(){
//some logic
}
$( window ).scroll(function(e,i) {
win_top = $( window ).scrollTop();
win_bottom = $( window ).height() + win_top;
//console.log( win_top,win_bottom );
$('.onvisible').each(function()
{
t = $(this).offset().top;
b = t + $(this).height();
if( t > win_top && b < win_bottom )
alert("do something");
});
});
$(function() {
$(document).click(function (){
if ($('#contentDiv').is(':visible')) {
alert("Visible");
} else {
alert("Hidden");
}
});
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<div id="contentDiv">Test I'm here</div>
<button onclick="$('#contentDiv').toggle();">Toggle the div</button>
<div id="welcometo">Özhan</div>
<input type="button" name="ooo"
onclick="JavaScript:
if(document.all.welcometo.style.display=='none') {
document.all.welcometo.style.display='';
} else {
document.all.welcometo.style.display='none';
}">
This code auto control not required query visible or unvisible control