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Changing onclick handler for an element after first click

div.onclick = function(data, dom) {
return function() {
if (data.seenAlready == true) { // HACK
$(this).children().toggle();
return;
}
recursiveSearch(data, dom);
// after this onclick, I want to assign it to a toggle like function. no clue how to do it.
}
}(child, mycontainer.appendChild(div));
I'm trying to swap the onclick method after first onclick on a dom element. I've just not had any success, it seems to some sort of closure loss, or something. I'm fine using jQuery.

You have two ways to do this and both ways are by using a jQuery function:
1) Use one API method - this will work just once. You will click it once and then you choose your own second handler and the first one will not fire again e.g.
$(myselector).one(function(){
$(this).click(myotherhandler);
});
Here is the link to this API http://api.jquery.com/one/.
2) You can choose the following way to replace the event handler .
$(myselector).click(function(){
$(this).off();
$(this).click("secondhandler");
});
this will turn the first handler off and will just fire second handler
Check this jsbin:
http://jsbin.com/fekuq/1/edit?html,js,output

Trigger event on specific condition

I have a div that will serve as container to other element, I have buttons that add element to that div.
Please see the demo for a get an idea about it.
So, what I want to do is to check before adding a new element is the div reached a maximum number of elements that I define, let's say 4.
I can check this condition before every add, but I am sure this is not the best way (we learned that if the code contains copy/paste then is not the best solution) Also, this is just a sample, in my case, I have many buttons..
Is there a way to have a listener like this?
$('#container').bind('divFull', function(){
//My code
});
So that I can disable buttons..

First, you have to listen to DOM change event, then you can trigger a custom event based on the number of children
$('#container').bind('DOMSubtreeModified', function(){
if($(this).children().length>=4){
$(this).trigger('divFull');
}
});
then you can bind to your custom divFull event
$('#container').bind('divFull', function(){
alert('container is full');
$('button').prop('disabled',true);
});
a working demo based on your example

I change a bit the #skafandri method because the event DOMSubtreeModified doesn't work on IE < 9 and it's depreciated.
The main change is to create a function which will call the divFull event if their is 4 children in the container.
var checkFull = function() {
if ($container.children().length === 4) {
$container.trigger('divFull');
}
}
$('#button1').click(function(){
$container.append('<div class="element">some text</div>');
checkFull();
});
Here is the demo.

How to check if there is already a click/event associated to an element

lets say I have
function trigger(){
$('a.pep').each(function(){
$('a.pep').click(function(){
console.log($(this).val());
});
});
}
function push(){
$('body').append('<a class="pep">hey mate i have no trigger yet</a>');
trigger(); //now i do but the others have duplicated trigger
}
$(document).ready(function(){
$('a.push').click(function(){
push();
});
});
So it seems that the click event is being applied twice/+ because the console.log is lauched more than once by click
How can i prevent this?

The problem is that you call $('a.pep').click() lots of times. (In fact, you bind as many click handlers as there are matching elements to each element. And then you do it again every time one of them is clicked.)
You should lever the DOM event bubbling model to handle this. jQuery helps you with the on method:
$(document.body).on('click', 'a.pep', function() {
console.log('element clicked');
$(document.body).append('<a class="pep">Click handlers handled automatically</a>');
});
See a working jsFiddle.
Note that I have removed the val call, because a elements can't have a value... Note also that the on method is introduced in jQuery 1.7; before that, use delegate:
$(document.body).delegate('a.pep', 'click', function() {

Small change to your trigger function is all you need. Just unbind the click event before binding to ensure that it is never added more than once. Also, you don't need to use each when binding events, it will add the event to each item automatically.
function trigger(){
$('a.pep').unbind('click').click(function() {
console.log($(this).val());
});
}

You can check using data('events') on any element if the required event is attached or not. For example to check if click event is attached or not try this.
if(!$('a.pep').data('events').click){
$('a.pep').click(function(){
console.log($(this).val());
});
}

you should use jQuery live here because you add DOM elements dynamicly and you want them to have the same click behaviour
function push(){
$('body').append('<a class="pep">hey mate i have no trigger yet</a>');
}
$(document).ready(function(){
$('a.push').click(function(){
push();
});
$('a.pep').live('click', function(){
console.log($(this).val());
});
});

Try:
if($('a.pep').data('events').click) {
//do something
}

i think if you use live() event you dont need to make function
$('a.pep').live('click', function(){
console.log($(this).val());
});

jQuery Issue: functions won't work on newly created HTML element

I have two functions: one that creates a new <textarea> when a button is clicked, and a second function that performs an action when the <textarea> is clicked (or blurred, changed, etc.) That second function selects elements based on a class name. It seems that the second function only works on those matching elements that existed when the page was loaded, but it will not activate on any newly created <textarea> elements. Can anyone figure out why and how to fix this? You'll find the code below. Thanks. --Jake
$('#add').click(function() {
$(this).before("<textarea class='test'></textarea>")
})
$('.test').blur(function () {
alert('just a test')
})

The textarea you create isn't around at the time jQuery assigns the action to elements tagged with the .test class. You'll need the live() function to make this work as desired.
$('.test').live('blur', function () {
alert('just a test')
});
Now any element tagged with .test will automatically bind the specified function on blur no matter when it's created.

You can bind it directly:
$('#add').click(function() {
$(this).before("<textarea class='test'></textarea>").prev().blur(function () {
alert('just a test');
});
});
Or place use jQuery's .delegate() method to place a handler on the parent of #add.
$('#add').click(function() {
$(this).before("<textarea class='test'></textarea>")
}).parent().delegate('.test','blur',function() {
alert('just a test');
});
This is a more efficient approach than using .live().

Add click event to Div and go to first link found

I think I've been too much time looking at this function and just got stuck trying to figure out the nice clean way to do it.
It's a jQuery function that adds a click event to any div that has a click CSS class. When that div.click is clicked it redirects the user to the first link found in it.
function clickabledivs() {
$('.click').each(
function (intIndex) {
$(this).bind("click", function(){
window.location = $( "#"+$(this).attr('id')+" a:first-child" ).attr('href');
});
}
);
}
The code simply works although I'm pretty sure there is a fairly better way to accomplish it, specially the selector I am using: $( "#"+$(this).attr('id')+" a:first-child" ). Everything looks long and slow. Any ideas?
Please let me know if you need more details.
PS: I've found some really nice jQuery benchmarking reference from Project2k.de here:
http://blog.projekt2k.de/2010/01/benchmarking-jquery-1-4/

Depending on how many of these div.click elements you have, you may want to use event delegation to handle these clicks. This means using a single event handler for all divs that have the click class. Then, inside that event handler, your callback acts based on which div.click the event originated from. Like this:
$('#div-click-parent').click(function (event)
{
var $target = $(event.target); // the element that fired the original click event
if ($target.is('div.click'))
{
window.location.href = $target.find('a').attr('href');
}
});
Fewer event handlers means better scaling - more div.click elements won't slow down your event handling.

optimized delegation with jQuery 1.7+
$('#div-click-parent').on('click', 'div.click', function () {
window.location.href = $(this).find('a').attr('href');
});

Instead of binding all the clicks on load, why not bind them on click? Should be much more optimal.
$(document).ready(function() {
$('.click').click(function() {
window.location = $(this).children('a:first').attr('href');
return false;
});
});

I would probably do something like;
$('.click').click(function(e){
window.location.href = $(this).find('a').attr('href');
});