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.
In one of our projects we load slides into our webpage with use of AJAX. After the slides are loaded I want jQuery to execute a plugin on all new injected elements automatically.
This is the code I found else where but it didn't do the trick. Also I've tried to replace .on function with the .bind function but then the whole site died and JavaScript crashes with an overflow.
function loaded(selector, callback) {
//trigger after page load.
jQuery(function () {
callback(jQuery(selector));
});
//trigger after page update eg ajax event or jquery insert.
jQuery("body").on('DOMNodeInserted', selector, function (e) {
callback(jQuery(this));
});
}
I got the problem reproduced in a JSFiddle.
A. Wolff,
Thanks your answer solves my problem. I have edited the loaded function to the following:
function loaded(selector, callback) {
//trigger after page load.
jQuery(function () {
callback(jQuery(selector));
});
var parentSelector = "* > " + selector;
//trigger after page update eg ajax event or jquery insert.
jQuery(document).on('DOMNodeInserted', parentSelector, function (e) {
callback(jQuery(this).find(selector));
});
}
Also I've forked a new working JSFiddle project for anyone who wants a full working example.
https://jsfiddle.net/9t8cahqv/
Thanks,
Jop
Event is fired on container DIV level so your selector isn't matching. You could use instead:
loaded(":has([title])", function(element) {
element.tooltip();
});
/**/
jQuery(document).on('DOMNodeInserted', selector, function(e) {
callback(jQuery(this).find('[title]'));
});
-jsFiddle-
Another way of doing this might be, watch for a DOM
var observer = new MutationObserver(function(mutations) {
mutations.forEach(function(mutation) {
if (!mutation.addedNodes) return
for (var i = 0; i < mutation.addedNodes.length; i++) {
// do things to your newly added nodes here
var node = mutation.addedNodes[i]
if ($(node).hasClass("some class")) {
$(node).remove()
}
//or with id
if ($(node).attr("id") == "someId") {
$(node).remove()
}
//or any other selector
}
})
})
observer.observe(document.body, {
childList: true,
subtree: true,
attributes: false,
characterData: false
})
To Stop Observe, use
observer.disconnect();
Been looking to figure out how with Twitter Flight can attach to dynamic created elements.
Having the following HTML
<article>Add element</article>
And the following component definition
var Article = flight.component(function () {
this.addElement = function () {
this.$node.parent().append('<article>Add element</article>');
};
this.after('initialize', function () {
this.on('click', this.addElement);
});
});
Article.attachTo('article');
Once a new element is created, the click event doesn't fire. Here's the fiddle: http://jsfiddle.net/smxx5/
That's not how you should be using Flight imho.
Each component should be isolated from the rest of the application, therefore you should avoid this.$node.parent()
On the other hand you can interact with descendants.
My suggestion is to create an "Articles manager" component that uses event delegation.
eg.
http://jsfiddle.net/kd75v/
<div class="js-articles">
<article class="js-article-add">Add element</article>
<div/>
and
var ArticlesManager = flight.component(function () {
this.defaultAttrs({
addSelector: '.js-article-add',
articleTpl: '<article class="js-article-add">Add element</article>'
});
this.addArticle = function () {
this.$node.append(this.attr.articleTpl);
};
this.after('initialize', function () {
this.on('click', {
addSelector: this.addArticle
});
});
});
ArticlesManager.attachTo('.js-articles');
Try attaching Article to each new article added:
JSFiddle: http://jsfiddle.net/TrueBlueAussie/smxx5/2/
var Article = flight.component(function () {
this.addElement = function () {
var newArticle = $('<article>Add element</article>');
this.$node.parent().append(newArticle);
Article.attachTo(newArticle);
};
this.after('initialize', function () {
this.on('click', this.addElement);
});
});
Article.attachTo('article');
The Article.attachTo('article'); at the end, that runs once on load, will only attach to existing article elements.
I hit this problem, and worked around is as follows...
Javascript: All thrown together for brevity, but could easily be separated.
(function(){
var TestComponent, LoaderComponent;
TestComponent = flight.component(function() {
this.doSomething = function()
{
console.log('hi there...');
};
this.after('initialize', function() {
this.on('mouseover', this.doSomething);
});
});
LoaderComponent = flight.component(function() {
this.attachComponents = function()
{
TestComponent.attachTo('.test');
};
this.after('initialize', function() {
// Initalise existing components
this.attachComponents();
// New item created, so re-attach components
this.on('newItem:testComponent', this.attachComponents);
});
});
LoaderComponent.attachTo('body');
}());
HTML: Note that one .test node exists. This will be picked up by Flight on initialization (i.e. not dynamic). We then add a second .test node using jQuery and fire off the event that the LoaderComponent is listening on.
<div class="test">
<p>Some sample text.</p>
</div>
<script>
$('body').append('<div class="test"><p>Some other text</p></div>').trigger('newItem:testComponent');
</script>
This is obviously a very contrived example, but should show that it's possible to use Flight with dynamically created elements.
Hope that helped :)
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