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jQuery delete trigger conditionally

I was wondering if Javascript or jQuery have a way to delete an event listener. Let's say I want to make a function that I want to trigger only once, for example let's say I want to have a button that shows some hidden elements on the document, I would make this function (assuming the hidden elements have a hidden class that hides them):
jQuery('#toggler').click(function() {
console.log('Hidden elements are now shown');
jQuery('.hidden').removeClass('hidden');
});
Simple enough, right ? Now, my actual problem comes in, I don't want jquery to run that function again and again each time the button is clicked, because the elements are already revealed, so is there a clean way to do it ? So, in this example after clicking the toggler multiple times I want to get only one console message.
I could do jQuery(this).unbind('click'), but this results into removing ALL triggers and I only want to remove the current trigger.
What I usually do when I face such scenarios is solve it like this (which is ugly and doesn't actually prevent code execution, but only handles the code's results) :
var toggler_clicked = false;
jQuery('#toggler').click(function() {
if(toggler_clicked) return;
toggler_clicked = true;
console.log('Hidden elements are now shown');
jQuery('.hidden').removeClass('hidden');
});
Also I don't want to use jQuery's one, because I will have the same problem when I'll need to delete the trigger conditionally, so if you can help please give me a dynamic answer.
Thanks in advance !

You have to name your function like that:
var myFunction = function() {
console.log('Hidden elements are now shown');
jQuery('.hidden').removeClass('hidden');
};
And bind it this way
jQuery('#toggler').click(myFunction);
Then you can unbind it with :
jQuery('#toggler').off('click',myFunction);
Without unbinding the other listeners

You can try this:
var myFunc = function() {
console.log('Hidden elements are now shown');
jQuery('.hidden').removeClass('hidden');
jQuery(this).unbind('click', myFunc);
};
jQuery('#toggler').click(myFunc);
This way of calling unbind is such that only the listener for myFunc handler is removed and not all the events connected to the click on the toggler.

I would use the .on() and its opposite .off() methods to attach/detach the event handler. It is the recommended way since 1.7 instead of the .bind() and .unbind() versions that became deprecated as of jQuery 3.0.
$("#toggler").on("click", function(event) {
console.log('Hidden elements are now shown');
$('.hidden').removeClass('hidden');
// if (/* Add your condition here */) {
$(this).off(event);
// }
});
$("#toggler").on("click", function(event) {
console.log('Hidden elements are now shown');
$('.hidden').removeClass('hidden');
// if (/* Add your condition here */) {
$(this).off(event);
// }
});
.hidden {
display: none;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<button id="toggler">Toggle</button>
<div class="hidden">
HIDDEN
</div>

Try this
var myFunction = function() {
console.log('Hidden elements are now shown');
jQuery('.hidden').removeClass('hidden');
};
Add the event listener like this:
jQuery('#toggler').addEventListener("click", myFunction);
And remove it like this:
jQuery('#toggler').removeEventListener("click", myFunction);
So all together this will do the trick:
var myFunction = function() {
console.log('Hidden elements are now shown');
jQuery('.hidden').removeClass('hidden');
jQuery('#toggler').removeEventListener("click", myFunction);
};
jQuery('#toggler').addEventListener("click", myFunction);
more about the HTML DOM removeEventListener() Method

Jquery unbind function takes 2 parameters eventType and handler
You can put your event listener into separate function like this:
var clickEventHandler = function(){
//your logic goes here
}
After you add listener as reference:
jQuery('#toggler').click(clickEventHandler);
And then, later, anytime, anywhere you want you can unbind that specific handler:
jQuery('#toggler').unbind('click', clickEventHandler);

What i used to do in the past is toggle the click behavior using css classes, ex i used to set a click listener on the parent and delegate to all of the children something that jquery is doing now by default i believe. Anyway based on the css class it will trigger an event for ex.
$('.some-parent-element').on(
'click',
'the-behavior-css-class',
function() { // do stuff here.... }
)
Now if you want to remove this behavior you can just toggle the class of the element and it should do the job. ex
$('.some-parent-element').on(
'click',
'hide-me-on-click-or-whatever',
function() {
$(this).toggleClass('hide-me-on-click-or-whatever')
// perform the action
}
)

You can check if the element has the class hidden

'.on' click not running function?

I have a function that when it runs new markup is generated on the fly...
$('.search input[type="image"]').on('click', function(){
// Open directions in a map
if($('#TXT_SAddr').val() === ''){
return false;
$('.directions .search').css('background' , '#ff0000');
} else {
var from = $('#TXT_SAddr').val();
var to = $('.postal-code').html();
var directions = 'http://maps.google.com/maps?saddr=' + from + '&daddr=' + to + '&output=embed';
var modal = '<div class="apply-modal modal"><a class="close-apply-now" style="margin-bottom: 20px;"><img src="http://site.co.uk/images/closeModal.png" alt="Close" style="border-width:0px;"></a><div class="holder"><iframe src="'+directions+'" style="border:none; width:100%; height:500px;" border="0"></iframe></div></div>';
$('body').prepend('<div class="modalOverlay"/>' + modal);
$('.modal').animate({
'opacity': 1,
'top': '100px'
}, 700, 'easeOutBack');
}
return false;
});
If you can see, the above generates a div with an anchor under the class name of 'close-apply-now'.
I now want to bind a function to this and I've tried using...
$('a.close-apply-now').on('click', function(){
alert('asdasd');
});
with no luck, can anybody see where I may be going wrong? Not even my alert is working.

Since the close-apply-now div is added dynamically, you need to use event delegation to register the event handler like:
// New way (jQuery 1.7+) - .on(events, selector, handler)
$('body').on('click', 'a.close-apply-now', function(event) {
event.preventDefault();
alert('asdasd');
});
This will attach your click event to any anchors with class close-apply-now within the body element.

The syntax for event delegation is slightly different.
The event need to be bind to an element which is already existing in the dom while the target element selector needs to be passed as the second argument
$(document).on('click', 'a.close-apply-now', function(){
alert('asdasd');
});

The close-apply-now div is added dynamically. You have to add the selector parameter, otherwise the event is directly bound (doesn't work for dynamically loaded content) instead of delegated. See http://api.jquery.com/on/#direct-and-delegated-events
Change your code to
$(document.body).on('click', '.update' ,function(){
The jQuery set receives the event then delegates it to elements matching the selector given as argument. This means that contrary to when using live, the jQuery set elements must exist when you execute the code.
Use jQuery's live() method. Description: Attach an event handler for all elements which match the current selector, now and in the future.
$("a.close-apply-now").live("click", function(){
alert('asdasd');
});
Try Both in Jsfiddle

dynamic selectors added when a function is performed

I am echoing some php lines with some class id and need to be able to use them with jquery .click as the selector. Is there a way to do this?? The property is not loaded with everthing else, it is added later on by php.
play.js-
$(".link").click( function(){
/* var l = ""
$.post('input_commands/move_to.php',{l:l}, function(data) {
text=data;
elem = $("#placeholder");
//delay=100;
addTextByDelay(text,elem,delay);
}); */
alert("omg whyyyyy");
});
get_locations.php -
if($array_loc['loc_north']>0){echo "<a class='link' id='location_north'>Go north to ".$array_loc_north['loc_name']."</a> <br>";}

You need to use a delegated event because your elements are added to the DOM dynamically (or after the event handler is created).
$(document).on('click', '.link', function(){
console.log("clicked");
});
In the above, the event is delegated to the document and so all clicks will be checked against the .link selector, even if the target is an element that didn't exist when the event was delegated.

in order to bind an event to a dynamic element (one that was added after first DOM load),
replace:
$(".link").click( function(){
with:
$(document).on('click', '.link', function(){
hope that helps.

If it's added dynamically using ajax you might want to call that selector and append the .click() on the callback.
$.ajax({
url: '...',
success: function(response) {
// do stuff with response (assume that .link will be appended)
$(".link").click( function(){
//stuff when click link
}
}
});
Otherwise, you can output the links with the onclick attribute and define a custom function:
if($array_loc['loc_north']>0){echo "<a class='link' id='location_north' onclick='customFunction(this)'>Go north to ".$array_loc_north['loc_name']."</a> <br>";}
and in the JS:
function customFunction(element) {
//do stuff here after the link was clicked
//element variable passed as parameter contains the link element clicked
}
PS: If there are multiple elements it's not ok to specify constant value for "id" attribute because it should be unique.

Trapping all `a` clicks including ones added dynamcally

I know you can bind to click events with jQuery like so:
$('a').click(function(){});
But what about html elements that are added dynamically? Lets say I have a div with the following contents:
<div>
<a href='location.html'>location</a>
</div>
Now I call:
$('a').click(
function(){
console.log("going to " + $(this).attr('href'));
return true;
});
And that will work fine. But if somewhere along the line I call
$('div').("<a href='location2.html'>location2</a>");
without explicitly binding that event handler to that event then the event handler will pick up on it.
Is it possible to rebind when ever a new a element is added. Or even better, when ever the location.href property is changing so I can add a get parameter to it every time.
For example if I was binding to a click event on an a element the event handler would be:
function(){
var newid = parseInt(Obj.Request('pageid'), 10) + 1;
location.href = $(this).attr('href') + '?pageid=' + newid.toString();
return false;
}
Assuming the Obj.Request is a function that returns a get parameter. (I already have this in place).

Use it in this manner:
$(document).on( 'click', 'a', function() {
console.log("going to " + $(this).attr('href'));
return true;
});
Working on your fiddle link.

You want to use the function .on.

$('a').on('click', function() {
//works on non dynamic elements present at page load
});
$('#some_non_dynamic_parent_ID').on('click', 'a', function() {
//works on dynamic elements added later
});

You want to use .on(), but as a delegation method.
Bind it to the closest static parent - for this example I'll just use body.
$('body').on('click', 'a', function(e){
e.preventDefault();
});
This will wait until the event bubbles up to the body element and check what the original target of the event was - if it was an a element, it'll fire the handler.

You can use .on() or live() functions if you use jquery upper then 1.7 version. About the difference of these functions you can read in this article

jQuery: Any way to "refresh" event handlers?

I have two divs, one that holds some stuff and the other with all possible stuff. Clicking on one of the divs will transfer items to the other div. The code I came up with is:
$("#holder > *").each(function() {
$(this).click(function(e) {
$(this).remove();
$("#bucket").append(this);
});
});
$("#bucket > *").each(function() {
$(this).click(function(e) {
$(this).remove();
$("#holder").append(this);
});
});
This one works perfectly, except that the event handlers need to be refreshed once I append or remove elements. What I mean is, if I first click on an element, it gets added to the other div, but if I click on this element again, nothing happens. I can do this manually but is there a better way to achieve this?

Try jquery live events .. the $.live(eventname, function) will bind to any current elements that match as well as elements added to the Dom in the future by javascript manipulation.
example:
$("#holder > *").live("click", function(e) {
$(this).remove();
$("#bucket").append(this);
});
$("#bucket > *").live("click", function(e) {
$(this).remove();
$("#holder").append(this);
});
Important:
Note that $.live has since been stripped from jQuery (1.9 onwards) and that you should instead use $.on.
I suggest that you refer to this answer for an updated example.

First, live is deprecated. Second, refreshing isn't what you want. You just need to attach the click handler to the right source, in this case: the document.
When you do
$(document).on('click', <id or class of element>, <function>);
the click handler is attached to the document. When the page is loaded, the click handler is attached to a specific instance of an element. When the page is reloaded, that specific instance is gone so the handler isn't going to register any clicks. But the page remains so attach the click handler to the document. Simple and easy.

Here you go, using the more intuitive delegate API:
var holder = $('#holder'),
bucket = $('#bucket');
holder.delegate('*', 'click', function(e) {
$(this).remove();
bucket.append(this);
});
bucket.delegate('*', 'click', function(e) {
$(this).remove();
holder.append(this);
});

EDIT: don't use live, it be deprecated!
Take advantage of the fact that events bubble. Using .on():
var = function( el1, el2 ) {
var things = $('#holder, #bucket');
things.each(function( index ) {
// for every click on or in this element
things.eq(index).on('click', '> *', function() {
// append will remove the element
// Number( !0 ) => 1, Number( !1 ) => 0
things.eq( Number(!index) ).append( this );
});
});
any click on any element (existing at the time of bind or not) will bubble up (assuming you haven't manually captured the event and stopped propagation). Thus, you can use that event delegation to bind only two events, one on each container. Every click that passed the selector test of the 2nd argument (in this case, > *, will remove that element and then append it to the alternate container as accesesed by things.eq( Number(!index) )

Have you looked at jQuery's live function?

The most Efficient way (dont load all event for all elements) it:
//NORMAL FUNCTION
function myfunction_click(){
//custom action
}
$('id_or_class_of_element').on('click', myfunction_click);
//LOAD OR REFRESH EVENT
$(document).on('click', 'id_or_class_of_element', myfunction_click);