Avoiding jQuery Mobile Memory Leak from Closures - javascript

I am attempting to create a jQuery plugin for my own use that can be used to setup a handler for jQuery mobile dialogs using a single command as such: $('#dialog').setup_dialog({ callback: callback_function });
However, my handler has a rather obvious memory leak due to closures in it:
$.fn.setup_dialog = function( options ) {
var settings = $.extend({
callback : 0
}, options);
var that = this;
return this.live('pagebeforeshow', function(event, ui) {
console.log("outside");
$('form', that).submit( function(e) {
var $inputs = $('form :input', that); // get all form inputs
var values = {};
$inputs.each(function() {
values[this.name] = $(this).val();
});
that.dialog('close');
if ( settings.callback && typeof(settings.callback) === "function" ) {
$('#'+ui.prevPage[0].id).live('pagebeforeshow', function() {
settings.callback(values, that);
console.log("inside");
});
}
return e.preventDefault();
});
});
}; /* setup_dialog */
If you ran the above code, you would see "inside" and "outside" printed first once, then three times (twice from a single submit), then six times (three times from a single submit), etc.
The intent of the code is to attach an event handler to the jQuery Mobile dialog when it comes up that will catch form submission, collect all the form values, and then pass them to a callback function that will modify the original page (that launched the dialog).
Note that because of the way jQuery Mobile uses AJAX to switch between pages, I need to use .live to bind the events (.bind or .one won't work).
Any ideas how I can avoid the events accumulating (and maybe clean up the code a bit as well)?

You are binding event handlers inside of other event handlers. And the outer event handlers are not unique events (they occur more than once) which means that your inner event handlers are being bound more than once.
A good fix is to remove the submit event handler from the pagebeforeshow event handler and place it in a pagecreate or pageinit event handler (these are unique and will only run once per dialog).
If you want to keep your current logic then you can just unbind event handlers when they run, so you won't be stacking multiple event handlers that do the same thing:
$.fn.setup_dialog = function( options ) {
var settings = $.extend({
callback : 0
}, options);
var that = this;
return this.live('pagebeforeshow', function(event, ui) {
console.log("outside");
$('form', that).submit( function(e) {
var $inputs = $('form :input', that); // get all form inputs
var values = {};
$inputs.each(function() {
values[this.name] = $(this).val();
});
that.dialog('close');
if ( settings.callback && typeof(settings.callback) === "function" ) {
$('#'+ui.prevPage[0].id).live('pagebeforeshow', function() {
settings.callback(values, that);
console.log("inside");
$(this).die('pagebeforeshow');//NEW, unbind the pagebeforeshow event handler for this element
//since it will be bound the next time the dialog is shown anyway
});
}
$(this).die('submit');//NEW, unbind the submit event handler for this form
//since it will be bound the next time the dialog is shown anyway
return e.preventDefault();
});
});
}; /* setup_dialog */
Here is the documentation for .die(): http://api.jquery.com/die/

The solution appears to be the following:
$.fn.setup_dialog = function( options ) {
var settings = $.extend({
callback : 0
}, options);
var that = this; var values = {}; var submitted = 0;
this.on('pageinit', function(event, ui) {
$('form', that).submit(function(e) {
var $inputs = $('form :input', that); // get all form inputs
submitted = 1;
$inputs.each(function() {
values[this.name] = $(this).val();
});
that.dialog('close');
return e.preventDefault();
});
$('.cancel-button', that).click(function() {
submitted = 0;
});
});
this.on('pagebeforehide', function(event, ui) {
if ( submitted && settings.callback && typeof(settings.callback) === "function" ) {
settings.callback(values, that);
}
});
}; /* setup_dialog */
There were multiple ways to do this, including creating a closure and calling $('#'+ui.prevPage[0].id).die().live('pagebeforeshow', function() {
Not convinced this is the nicest solution though, so I'd love to hear some better ideas.

Related

How to hook on library function (Golden Layout) and call additional methods

I'm using a library called Golden Layout, it has a function called destroy which will close all the application window, on window close or refesh
I need to add additional method to the destroy function. I need to removeall the localstorage aswell.
How do i do it ? Please help
Below is the plugin code.
lm.LayoutManager = function( config, container ) {
....
destroy: function() {
if( this.isInitialised === false ) {
return;
}
this._onUnload();
$( window ).off( 'resize', this._resizeFunction );
$( window ).off( 'unload beforeunload', this._unloadFunction );
this.root.callDownwards( '_$destroy', [], true );
this.root.contentItems = [];
this.tabDropPlaceholder.remove();
this.dropTargetIndicator.destroy();
this.transitionIndicator.destroy();
this.eventHub.destroy();
this._dragSources.forEach( function( dragSource ) {
dragSource._dragListener.destroy();
dragSource._element = null;
dragSource._itemConfig = null;
dragSource._dragListener = null;
} );
this._dragSources = [];
},
I can access the destroy method in the component like this
this.layout = new GoldenLayout(this.config, this.layoutElement.nativeElement);
this.layout.destroy();`
My code
#HostListener('window:beforeunload', ['$event'])
beforeunloadHandler(event) {
var originalDestroy = this.layout.destroy;
this.layout.destroy = function() {
// Call the original
originalDestroy.apply(this, arguments);
localStorage.clear();
};
}
Looking at the documentation, GoldenLayout offers an itemDestroyed event you could hook to do your custom cleanup. The description is:
Fired whenever an item gets destroyed.
If for some reason you can't, the general answer is that you can easily wrap the function:
var originalDestroy = this.layout.destroy;
this.layout.destroy = function() {
// Call the original
originalDestroy.apply(this, arguments);
// Do your additional work here
};
You may be able to do this for all instances if necessary by modifying GoldenLayout.prototype:
var originalDestroy = GoldenLayout.prototype.destroy;
GoldenLayout.prototype.destroy = function() {
// Call the original
originalDestroy.apply(this, arguments);
// Do your additional work here
};
Example:
// Stand-in for golden laout
function GoldenLayout() {
}
GoldenLayout.prototype.destroy = function() {
console.log("Standard functionality");
};
// Your override:
var originalDestroy = GoldenLayout.prototype.destroy;
GoldenLayout.prototype.destroy = function() {
// Call the original
originalDestroy.apply(this, arguments);
// Do your additional work here
console.log("Custom functionality");
};
// Use
var layout = new GoldenLayout();
layout.destroy();
Hooking into golden layout is the intended purpose for the events.
As briefly touched on by #T.J. Crowder, there is the itemDestroyed event which is called when an item in the layout is destroyed.
You can just listen for this event like such:
this.layout.on('itemDestroyed', function() {
localStorage.clear();
})
However, this event is called every time anything is destroyed, and propagates down the tree, even just by closing a tab. This means that if you call destroy on the layout root, you will get an event for every RowOrColumn, Stack and Component
I would recommend to check the item passed into the event and ignore if not the main window (root item)
this.layout.on('itemDestroyed', function(item) {
if (item.type === "root") {
localStorage.clear();
}
})

Event handler isn't working

I have one input which have event listener onblur and button which have event listener onclick.
This is how I organized it
document.addEventListener("DOMContentLoaded", function() {
window.searchButton = document.getElementById("searchButton");
window.searchInput = document.getElementById("searchInput");
searchInput.onfocus = searchFocus;
searchInput.onblur = searchBlur;
searchButton.onclick = search;
});
var resize = function(self, newSize) {
self.setAttribute("size", newSize);
};
var searchFocus = function() {
event.stopPropagation();
resize(searchInput, 30);
};
var searchBlur = function() {
if (searchInput.value === "") {
resize(searchInput, 10);
}
};
var search = function() {
event.stopPropagation();
};
But when the input is focused and I am clicking on the button, working onblur function, but onclick function isn't working. Why and how can I fix that?
Your search callback should have event in its param list. Same is true for searchFocus
var search = function(event){
event.stopPropagation();
};
Also, you might want to check that your DOMContentLoaded handler is firing. Depending upon how your scripts are organized/loaded, it is possible that the DOM has already loaded and that event fired before you register the handler. That's a common oversight.
How to detect if DOMContentLoaded was fired

Afterevent event listener

I will take keydown event listener as an example.
One can use
$('#my-input').keydown(function(){
//actions goes here
});
I understand that the above event listener runs when it encounters a keydown event.
I need an "afterkeydown event" like so:
$('#my-input').afterkeydown(function(){
//actions after keydown listener has occured
});
I however do not want to use a keyup event listener nor any kind of timer to achieve this
because a keyup event listener does not get trigger when a key is repeatedly held and timers are slow.
Is a "callback event listener" on keydown possible under these limitations, if so, can it be generalized to all Jquery event listeners? Meaning, is it possible to create an 'afterclick', 'afterdrop', 'afterclick', ... event listener for Jquery?
Since it sounds like what you're really trying to do is to get notified anytime a textarea has been changed, here's some code I've used for that specific issue. It will call your callback anytime the content has been changed via keyboard, drag/drop, mouse, etc...
(function($) {
var isIE = false;
// conditional compilation which tells us if this is IE
/*#cc_on
isIE = true;
#*/
// Events to monitor if 'input' event is not supported
// The boolean value is whether we have to
// re-check after the event with a setTimeout()
var events = [
"keyup", false,
"blur", false,
"focus", false,
"drop", true,
"change", false,
"input", false,
"textInput", false,
"paste", true,
"cut", true,
"copy", true,
"contextmenu", true
];
// Test if the input event is supported
// It's too buggy in IE so we never rely on it in IE
if (!isIE) {
var el = document.createElement("input");
var gotInput = ("oninput" in el);
if (!gotInput) {
el.setAttribute("oninput", 'return;');
gotInput = typeof el["oninput"] == 'function';
}
el = null;
// if 'input' event is supported, then use a smaller
// set of events
if (gotInput) {
events = [
"input", false,
"textInput", false
];
}
}
$.fn.userChange = function(fn, data) {
function checkNotify(e, delay) {
var self = this;
var this$ = $(this);
if (this.value !== this$.data("priorValue")) {
this$.data("priorValue", this.value);
fn.call(this, e, data);
} else if (delay) {
// The actual data change happens aftersome events
// so we queue a check for after
// We need a copy of e for setTimeout() because the real e
// may be overwritten before the setTimeout() fires
var eCopy = $.extend({}, e);
setTimeout(function() {checkNotify.call(self, eCopy, false)}, 1);
}
}
// hook up event handlers for each item in this jQuery object
// and remember initial value
this.each(function() {
var this$ = $(this).data("priorValue", this.value);
for (var i = 0; i < events.length; i+=2) {
(function(i) {
this$.on(events[i], function(e) {
checkNotify.call(this, e, events[i+1]);
});
})(i);
}
});
}
})(jQuery);
Usage is:
$("#whatever").userChange(yourCallbackFn, optionalData);

how to fix my JQuery bug?

The script is on jsfiddle here : CODE
What it does at the moment: it's a form that have two types of URL field textarea and input, it converts the texts in those fields to a link to be click-able.
How it works: if you click next to the link/links you can edit the link or on a double click on the link. IF you click once on the link it takes you to that page.
Last update: i added the .trigger('blur'); on the last line, Because before i did that, the text area was showing the links like one merged link, for example : test.com and test2.com were showing test.comtest2.com, after i added this last update, the split for textera work also on the load of page not just on the edit of textarea ( it was working without the last update but only when you edit the textarea and put between links a space, and i want it to be working on the load of page because the textarea format was sent already as one link pre row ).
My problem: after i did this last update, the double click is messed up, it should just be able to edit the link and don't go to that page unless one click, but now it edits it and in like one second it goes also to that page. I want the double click just to edit without going to that page. and to go only with one click.
Thanks a lot in advance!
The code also here:
$('.a0 a').click(function(){
var href = $(this).attr('href');
// Redirect only after 500 milliseconds
if (!$(this).data('timer')) {
$(this).data('timer', setTimeout(function () {
window.open(href, '_blank')
}, 500));
}
return false; // Prevent default action (redirecting)});
$('.a0').dblclick(function(){
clearTimeout($(this).find('a').data('timer'));
$(this).find('a').data('timer', null);
$(this).parent().find('input,textarea').val($(this).find('a').text()).show().focus();
$(this).hide();})
$('.a0').click(function(){
$(this).parent().find('input,textarea').val($.map($(this).find('a'),function(el){return $(el).text();}).join(" ")).show().focus();
$(this).hide();})
$('#url0, #url1,#url4').each(
function(index, element){
$(element).blur(function(){
var vals = this.value.split(/\s+/),
$container = $(this).hide().prev().show().empty();
$.each(vals, function(i, val) {
if (i > 0) $("<span><br /></span>").appendTo($container);
$("<a />").html(val).attr('href',/^https?:\/\//.test(val) ? val : 'http://' + val).appendTo($container);;
}); })
}).trigger('blur');
A double-click is always predeeded by the following chain of events:
mousedown, mouseup, click, mousedown, mouseup, click, dblclick
You can make your click-events wait and check if a double-click event happened afterwards. setTimeout is your friend. Be sure to copy any data you need from the event object passed to your handler. That object is destroyed after the handler finished - which is before your delayed handler is invoked.
You can manually dispatch a double click event to prevent click-events from being executed prior to them. See the Fiddle
// ms to wait for a doubleclick
var doubleClickThreshold = 300;
// timeout container
var clickTimeout;
$('#test').on('click', function(e) {
var that = this;
var event;
if (clickTimeout) {
try {
clearTimeout(clickTimeout);
} catch(x) {};
clickTimeout = null;
handleDoubleClick.call(that, e);
return;
}
// the original event object is destroyed after the handler finished
// so we'll just copy over the data we might need. Skip this, if you
// don't access the event object at all.
event = $.extend(true, {}, e);
// delay click event
clickTimeout = setTimeout(function() {
clickTimeout = null;
handleClick.call(that, event);
}, doubleClickThreshold);
});
function handleClick(e) {
// Note that you cannot use event.stopPropagation(); et al,
// they wouldn't have any effect, since the actual event handler
// has already returned
console.log("click", this, e);
alert("click");
}
function handleDoubleClick(e) {
// this handler executes synchronously with the actual event handler,
// so event.stopPropagation(); et al can be used!
console.log("doubleclick", this, e);
alert("doubleclick");
}
jsfiddle refuses to load on my connection for some reason, so cant see the code.
Based on your explanation i suggest you look into event.preventDefault to add more control on what should happen on your click events. This could be used in conjunction with #rodneyrehm's answer.
Refer to my previous answer.
For your quick reference, I have pasted my answer here
$('.a0 a').click(function(){
var href = $(this).attr('href');
// Redirect only after 500 milliseconds
if (!$(this).data('timer')) {
$(this).data('timer', setTimeout(function() {
window.open(href, '_blank')
}, 500));
}
return false; // Prevent default action (redirecting)
});
$('.a0').dblclick(function(){
var txt = document.createElement('div');
$.each($(this).find('a'), function(i, val) {
clearTimeout($(val).data('timer'));
$(val).data('timer', null);
$(txt).append($(val).text());
$("<br>").appendTo(txt);
});
var content = $(this).parent().find('input,textarea');
var text = "";
$.each($(txt).html().split("<br>"), function(i, val) {
if (val != "")
text += val + "\n";
});
$(content).html(text);
$(this).hide();
$(content).show().focus();
})
$('#url0, #url1, #url4').each(function(index, element) {
$(element).blur(function(){
if ($(this).val().length == 0)
$(this).show();
else
{
var ele = this;
var lines = $(ele).val().split("\n");
var divEle = $(ele).hide().prev().show().empty();
$.each(lines, function(i, val) {
$("<a />").html(val).attr({
'href': val,
'target': '_blank'}).appendTo(divEle);
$("<br/>").appendTo(divEle);
});
}
});
});
​

How do you log all events fired by an element in jQuery?

I'd like to see all the events fired by an input field as a user interacts with it. This includes stuff like:
Clicking on it.
Clicking off it.
Tabbing into it.
Tabbing away from it.
Ctrl+C and Ctrl+V on the keyboard.
Right click -> Paste.
Right click -> Cut.
Right click -> Copy.
Dragging and dropping text from another application.
Modifying it with Javascript.
Modifying it with a debug tool, like Firebug.
I'd like to display it using console.log. Is this possible in Javascript/jQuery, and if so, how do I do it?
I have no idea why no-one uses this... (maybe because it's only a webkit thing)
Open console:
monitorEvents(document.body); // logs all events on the body
monitorEvents(document.body, 'mouse'); // logs mouse events on the body
monitorEvents(document.body.querySelectorAll('input')); // logs all events on inputs
$(element).on("click mousedown mouseup focus blur keydown change",function(e){
console.log(e);
});
That will get you a lot (but not all) of the information on if an event is fired... other than manually coding it like this, I can't think of any other way to do that.
There is a nice generic way using the .data('events') collection:
function getEventsList($obj) {
var ev = new Array(),
events = $obj.data('events'),
i;
for(i in events) { ev.push(i); }
return ev.join(' ');
}
$obj.on(getEventsList($obj), function(e) {
console.log(e);
});
This logs every event that has been already bound to the element by jQuery the moment this specific event gets fired. This code was pretty damn helpful for me many times.
Btw: If you want to see every possible event being fired on an object use firebug: just right click on the DOM element in html tab and check "Log Events". Every event then gets logged to the console (this is sometimes a bit annoying because it logs every mouse movement...).
$('body').on("click mousedown mouseup focus blur keydown change mouseup click dblclick mousemove mouseover mouseout mousewheel keydown keyup keypress textInput touchstart touchmove touchend touchcancel resize scroll zoom focus blur select change submit reset",function(e){
console.log(e);
});
I know the answer has already been accepted to this, but I think there might be a slightly more reliable way where you don't necessarily have to know the name of the event beforehand. This only works for native events though as far as I know, not custom ones that have been created by plugins. I opted to omit the use of jQuery to simplify things a little.
let input = document.getElementById('inputId');
Object.getOwnPropertyNames(input)
.filter(key => key.slice(0, 2) === 'on')
.map(key => key.slice(2))
.forEach(eventName => {
input.addEventListener(eventName, event => {
console.log(event.type);
console.log(event);
});
});
I hope this helps anyone who reads this.
EDIT
So I saw another question here that was similar, so another suggestion would be to do the following:
monitorEvents(document.getElementById('inputId'));
Old thread, I know. I needed also something to monitor events and wrote this very handy (excellent) solution. You can monitor all events with this hook (in windows programming this is called a hook). This hook does not affects the operation of your software/program.
In the console log you can see something like this:
Explanation of what you see:
In the console log you will see all events you select (see below "how to use") and shows the object-type, classname(s), id, <:name of function>, <:eventname>.
The formatting of the objects is css-like.
When you click a button or whatever binded event, you will see it in the console log.
The code I wrote:
function setJQueryEventHandlersDebugHooks(bMonTrigger, bMonOn, bMonOff)
{
jQuery.fn.___getHookName___ = function()
{
// First, get object name
var sName = new String( this[0].constructor ),
i = sName.indexOf(' ');
sName = sName.substr( i, sName.indexOf('(')-i );
// Classname can be more than one, add class points to all
if( typeof this[0].className === 'string' )
{
var sClasses = this[0].className.split(' ');
sClasses[0]='.'+sClasses[0];
sClasses = sClasses.join('.');
sName+=sClasses;
}
// Get id if there is one
sName+=(this[0].id)?('#'+this[0].id):'';
return sName;
};
var bTrigger = (typeof bMonTrigger !== "undefined")?bMonTrigger:true,
bOn = (typeof bMonOn !== "undefined")?bMonOn:true,
bOff = (typeof bMonOff !== "undefined")?bMonOff:true,
fTriggerInherited = jQuery.fn.trigger,
fOnInherited = jQuery.fn.on,
fOffInherited = jQuery.fn.off;
if( bTrigger )
{
jQuery.fn.trigger = function()
{
console.log( this.___getHookName___()+':trigger('+arguments[0]+')' );
return fTriggerInherited.apply(this,arguments);
};
}
if( bOn )
{
jQuery.fn.on = function()
{
if( !this[0].__hooked__ )
{
this[0].__hooked__ = true; // avoids infinite loop!
console.log( this.___getHookName___()+':on('+arguments[0]+') - binded' );
$(this).on( arguments[0], function(e)
{
console.log( $(this).___getHookName___()+':'+e.type );
});
}
var uResult = fOnInherited.apply(this,arguments);
this[0].__hooked__ = false; // reset for another event
return uResult;
};
}
if( bOff )
{
jQuery.fn.off = function()
{
if( !this[0].__unhooked__ )
{
this[0].__unhooked__ = true; // avoids infinite loop!
console.log( this.___getHookName___()+':off('+arguments[0]+') - unbinded' );
$(this).off( arguments[0] );
}
var uResult = fOffInherited.apply(this,arguments);
this[0].__unhooked__ = false; // reset for another event
return uResult;
};
}
}
Examples how to use it:
Monitor all events:
setJQueryEventHandlersDebugHooks();
Monitor all triggers only:
setJQueryEventHandlersDebugHooks(true,false,false);
Monitor all ON events only:
setJQueryEventHandlersDebugHooks(false,true,false);
Monitor all OFF unbinds only:
setJQueryEventHandlersDebugHooks(false,false,true);
Remarks/Notice:
Use this for debugging only, turn it off when using in product final
version
If you want to see all events, you have to call this function
directly after jQuery is loaded
If you want to see only less events, you can call the function on the time you need it
If you want to auto execute it, place ( )(); around function
Hope it helps! ;-)
https://github.com/robertleeplummerjr/wiretap.js
new Wiretap({
add: function() {
//fire when an event is bound to element
},
before: function() {
//fire just before an event executes, arguments are automatic
},
after: function() {
//fire just after an event executes, arguments are automatic
}
});
Just add this to the page and no other worries, will handle rest for you:
$('input').live('click mousedown mouseup focus keydown change blur', function(e) {
console.log(e);
});
You can also use console.log('Input event:' + e.type) to make it easier.
STEP 1: Check the events for an HTML element on the developer console:
STEP 2: Listen to the events we want to capture:
$(document).on('ch-ui-container-closed ch-ui-container-opened', function(evt){
console.log(evt);
});
Good Luck...
I recently found and modified this snippet from an existing SO post that I have not been able to find again but I've found it very useful
// specify any elements you've attached listeners to here
const nodes = [document]
// https://developer.mozilla.org/en-US/docs/Web/Events
const logBrowserEvents = () => {
const AllEvents = {
AnimationEvent: ['animationend', 'animationiteration', 'animationstart'],
AudioProcessingEvent: ['audioprocess'],
BeforeUnloadEvent: ['beforeunload'],
CompositionEvent: [
'compositionend',
'compositionstart',
'compositionupdate',
],
ClipboardEvent: ['copy', 'cut', 'paste'],
DeviceLightEvent: ['devicelight'],
DeviceMotionEvent: ['devicemotion'],
DeviceOrientationEvent: ['deviceorientation'],
DeviceProximityEvent: ['deviceproximity'],
DragEvent: [
'drag',
'dragend',
'dragenter',
'dragleave',
'dragover',
'dragstart',
'drop',
],
Event: [
'DOMContentLoaded',
'abort',
'afterprint',
'beforeprint',
'cached',
'canplay',
'canplaythrough',
'change',
'chargingchange',
'chargingtimechange',
'checking',
'close',
'dischargingtimechange',
'downloading',
'durationchange',
'emptied',
'ended',
'error',
'fullscreenchange',
'fullscreenerror',
'input',
'invalid',
'languagechange',
'levelchange',
'loadeddata',
'loadedmetadata',
'noupdate',
'obsolete',
'offline',
'online',
'open',
'open',
'orientationchange',
'pause',
'play',
'playing',
'pointerlockchange',
'pointerlockerror',
'ratechange',
'readystatechange',
'reset',
'seeked',
'seeking',
'stalled',
'submit',
'success',
'suspend',
'timeupdate',
'updateready',
'visibilitychange',
'volumechange',
'waiting',
],
FocusEvent: [
'DOMFocusIn',
'DOMFocusOut',
'Unimplemented',
'blur',
'focus',
'focusin',
'focusout',
],
GamepadEvent: ['gamepadconnected', 'gamepaddisconnected'],
HashChangeEvent: ['hashchange'],
KeyboardEvent: ['keydown', 'keypress', 'keyup'],
MessageEvent: ['message'],
MouseEvent: [
'click',
'contextmenu',
'dblclick',
'mousedown',
'mouseenter',
'mouseleave',
'mousemove',
'mouseout',
'mouseover',
'mouseup',
'show',
],
// https://developer.mozilla.org/en-US/docs/Web/Guide/Events/Mutation_events
MutationNameEvent: ['DOMAttributeNameChanged', 'DOMElementNameChanged'],
MutationEvent: [
'DOMAttrModified',
'DOMCharacterDataModified',
'DOMNodeInserted',
'DOMNodeInsertedIntoDocument',
'DOMNodeRemoved',
'DOMNodeRemovedFromDocument',
'DOMSubtreeModified',
],
OfflineAudioCompletionEvent: ['complete'],
OtherEvent: ['blocked', 'complete', 'upgradeneeded', 'versionchange'],
UIEvent: [
'DOMActivate',
'abort',
'error',
'load',
'resize',
'scroll',
'select',
'unload',
],
PageTransitionEvent: ['pagehide', 'pageshow'],
PopStateEvent: ['popstate'],
ProgressEvent: [
'abort',
'error',
'load',
'loadend',
'loadstart',
'progress',
],
SensorEvent: ['compassneedscalibration', 'Unimplemented', 'userproximity'],
StorageEvent: ['storage'],
SVGEvent: [
'SVGAbort',
'SVGError',
'SVGLoad',
'SVGResize',
'SVGScroll',
'SVGUnload',
],
SVGZoomEvent: ['SVGZoom'],
TimeEvent: ['beginEvent', 'endEvent', 'repeatEvent'],
TouchEvent: [
'touchcancel',
'touchend',
'touchenter',
'touchleave',
'touchmove',
'touchstart',
],
TransitionEvent: ['transitionend'],
WheelEvent: ['wheel'],
}
const RecentlyLoggedDOMEventTypes = {}
Object.keys(AllEvents).forEach((DOMEvent) => {
const DOMEventTypes = AllEvents[DOMEvent]
if (Object.prototype.hasOwnProperty.call(AllEvents, DOMEvent)) {
DOMEventTypes.forEach((DOMEventType) => {
const DOMEventCategory = `${DOMEvent} ${DOMEventType}`
nodes.forEach((node) => {
node.addEventListener(
DOMEventType,
(e) => {
if (RecentlyLoggedDOMEventTypes[DOMEventCategory]) return
RecentlyLoggedDOMEventTypes[DOMEventCategory] = true
// NOTE: throttle continuous events
setTimeout(() => {
RecentlyLoggedDOMEventTypes[DOMEventCategory] = false
}, 1000)
const isActive = e.target === document.activeElement
// https://developer.mozilla.org/en-US/docs/Web/API/DocumentOrShadowRoot/activeElement
const hasActiveElement = document.activeElement !== document.body
const msg = [
DOMEventCategory,
'target:',
e.target,
...(hasActiveElement
? ['active:', document.activeElement]
: []),
]
if (isActive) {
console.info(...msg)
}
},
true,
)
})
})
}
})
}
logBrowserEvents()
// export default logBrowserEvents
function bindAllEvents (el) {
for (const key in el) {
if (key.slice(0, 2) === 'on') {
el.addEventListener(key.slice(2), e => console.log(e.type));
}
}
}
bindAllEvents($('.yourElement'))
This uses a bit of ES6 for prettiness, but can easily be translated for legacy browsers as well. In the function attached to the event listeners, it's currently just logging out what kind of event occurred but this is where you could print out additional information, or using a switch case on the e.type, you could only print information on specific events
Here is a non-jquery way to monitor events in the console with your code and without the use of monitorEvents() because that only works in Chrome Developer Console. You can also choose to not monitor certain events by editing the no_watch array.
function getEvents(obj) {
window["events_list"] = [];
var no_watch = ['mouse', 'pointer']; // Array of event types not to watch
var no_watch_reg = new RegExp(no_watch.join("|"));
for (var prop in obj) {
if (prop.indexOf("on") === 0) {
prop = prop.substring(2); // remove "on" from beginning
if (!prop.match(no_watch_reg)) {
window["events_list"].push(prop);
window.addEventListener(prop, function() {
console.log(this.event); // Display fired event in console
} , false);
}
}
}
window["events_list"].sort(); // Alphabetical order
}
getEvents(document); // Put window, document or any html element here
console.log(events_list); // List every event on element
How to listen for all events on an Element (Vanilla JS)
For all native events, we can retrieve a list of supported events by iterating over the target.onevent properties and installing our listener for all of them.
for (const key in target) {
if(/^on/.test(key)) {
const eventType = key.substr(2);
target.addEventListener(eventType, listener);
}
}
The only other way that events are emitted which I know of is via EventTarget.dispatchEvent, which every Node and thefore every Element inherits.
To listen for all these manually triggered events, we can proxy the dispatchEvent method globally and install our listener just-in-time for the event whose name we just saw ✨ ^^
const dispatchEvent_original = EventTarget.prototype.dispatchEvent;
EventTarget.prototype.dispatchEvent = function (event) {
if (!alreadyListenedEventTypes.has(event.type)) {
target.addEventListener(event.type, listener, ...otherArguments);
alreadyListenedEventTypes.add(event.type);
}
dispatchEvent_original.apply(this, arguments);
};
🔥 function snippet 🔥
function addEventListenerAll(target, listener, ...otherArguments) {
// install listeners for all natively triggered events
for (const key in target) {
if (/^on/.test(key)) {
const eventType = key.substr(2);
target.addEventListener(eventType, listener, ...otherArguments);
}
}
// dynamically install listeners for all manually triggered events, just-in-time before they're dispatched ;D
const dispatchEvent_original = EventTarget.prototype.dispatchEvent;
function dispatchEvent(event) {
target.addEventListener(event.type, listener, ...otherArguments); // multiple identical listeners are automatically discarded
dispatchEvent_original.apply(this, arguments);
}
EventTarget.prototype.dispatchEvent = dispatchEvent;
if (EventTarget.prototype.dispatchEvent !== dispatchEvent) throw new Error(`Browser is smarter than you think!`);
}
// usage example
const input = document.querySelector('input');
addEventListenerAll(input, (evt) => {
console.log(evt.type);
});
input.focus();
input.click();
input.dispatchEvent(new Event('omg!', { bubbles: true }));
// usage example with `useCapture`
// (also receives `bubbles: false` events, but in reverse order)
addEventListenerAll(
input,
(evt) => { console.log(evt.type); },
true
);
document.body.dispatchEvent(new Event('omfggg!', { bubbles: false }));

Categories

Resources