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JQuery select elements in <span> that doesn't exist initially

I've been looking for so long and found several answers that suggest using .on() as in $('.idOfMyElemenet').on() works even for elements that don't exist yet. But this doesn't seem to be finding the element. Am I doing something wrong?
The highest level <span> (in screenshot) does not exist until I click on a drop-down. Ultimately I'm trying to trigger an event when the user clicks on any of the <li> (aka selects an option from the drop-down).
$(document).ready(function () {
var test = "#select2-id_customer-results";
$(test).on("click", function() {
console.log('hello')
})
})
EDIT:
Thanks to Drew Baker - I think his second solution is the way to go. But not quite there yet...
From the select2 documentation
All public events are relayed using the jQuery event system, and they
are triggered on the <select> element that Select2 is attached to.
So I tried listening to it via the id (which doesn't seem to exist but would probably be id_customer) and the class. The class I added below did not work. Is there a way to listen to this using Jquery?
$(document).ready(function () {
// console.log($('#id_customer'));
$('.modelselect2 form-control select2-hidden-accessible').on('select2:select', function (e) {
var data = e.params.data;
console.log(data);
});
});

I'll answer your question, but then give you a better solution.
First, you need to make sure the thing you are attaching .on() to actually exists. I typically use a containing DIV or failing that body or html will work.
Secondly you are missing a parameter that tells jQuery the thing you are looking to watch to be clicked on. In this case, I'm assuming it is the UL tag with the ID you provided.
This should do what you want:
$(document).ready(function () {
$('body').on("click", "#select2-id_customer-results", function() {
console.log('hello')
})
})
But a better solution would be to use the Select2 API to have it tell you when something is selected. This will be way more reliable and should make your code work after upgrades to Select2.
Something like this:
$('select[name="customer"]').on('select2:select', function (e) {
var data = e.params.data;
console.log(data);
});
NOTE: #mySelect2 is probably not what you have. Use whatever ID you used to initialize Select2 in jQuery.
You can read more about that API here: https://select2.org/programmatic-control/events

if your element is dynamically generated and you want to target that specific element. You need to specify a static container/parent element to indicate where it belongs.
Try this:
$( '#dynamicallyAddedElement' ).on( 'click', '#wrapper', function () { ... });
//where #wrapper is a static parent element in which you add the dynamic links.
So, you have a wrapper which is hard-coded into the HTML source code:
PS. Hope I helped in some way.

If you need to trigger an event when click on <li> elements, you have to use that elements id or class as the selector. Check the below code:
$(document).ready(function () {
var test = ".select2-results__option";
$(test).on("click", function() {
console.log('hello')
})
})

It turns out this is an old bug in django-auto-complete.
The code below works. I have no idea why but now I can move on.
Note: the 'name' is the value of the select2 select element (see screenshot at bottom)
document.querySelector('select[name="customer"]').onchange=function() {
console.log("myselect2name changed");
};

Checkbox and click event handling

I'm trying to set a textbox to 'readonly', add a class, and put a text into the textbox at that moment when I check the checkbox. Moreover, I'm also trying to remove 'readonly' attribute from the textbox, add a class, and delete text in the textbox.
I have
$('#CheckBoxSectionCode').click(function () {
if ($(this).is(':checked')) {
$('#TextBoxSectionCode').attr('readonly', 'readonly');
$('#TextBoxSectionCode').addClass('disabled');
$('#TextBoxSectionCode').text(document.getElementById('TextBoxSectionName').val);
}
else {
$('#TextBoxSectionCode').attr('readonly', false);
$('#TextBoxSectionCode').addClass('abled');
$('#TextBoxSectionCode').text('');
}
});
This code doesn't work for me.
Thanks,
Phillip
Thanks everyone for answers.
According to your comments and answers, I've changed my code but it's still not working.
$('#CheckBoxSectionCode').click(function () {
if ($(this).is(':checked')) {
$('#TextBoxSectionCode').prop('readonly', true);
$('#TextBoxSectionCode').addClass('disabled');
$('#TextBoxSectionCode').text('disabled');
}
else {
$('#TextBoxSectionCode').prop('readonly', false);
$('#TextBoxSectionCode').removeClass('disabled').addClass('enabled');
$('#TextBoxSectionCode').text('');
}
});
I'm using chrome browser to run this code, and using developer tools in chrome and put a break point at the code above to see what's happening in the jquery. However, when I click the check box to check/uncheck, nothing happens there.

document.getElementById('TextBoxSectionName').val this is wrong. You really should cache your jQuery object so it's not navigating the DOM over and over. Then you mix in native JS and .val is not a DOM property or method, nor is it a jQuery property, it should be .value for a DOM object or .val() for a jQuery object.
Obligatory explanation by #Archy Wilhes:
"Just to clarify; when #SterlingArcher says caching the jQuery object,
she/he means doing something like var obj = $('#TextBoxSectionCode')
then calling the functions using the variable like this:
obj.attr(...); obj.addClass(...). Every time you do a $(something) you
are calling a function in jQuery that looks for the DOM."

since everytime you are adding the class the element is going to end up having both the two classes. Consider removing the other class before adding one. For example,
$(selector).removeClass('disabled').addClass('enabled')

Try with change event instead of click:
$('#CheckBoxSectionCode').change(function () {
if ($(this).is(':checked')) {
$('#TextBoxSectionCode').attr('readonly', 'readonly');
$('#TextBoxSectionCode').addClass('disabled');
$('#TextBoxSectionCode').text(document.getElementById('TextBoxSectionName').val);
}
else {
$('#TextBoxSectionCode').attr('readonly', false);
$('#TextBoxSectionCode').addClass('abled');
$('#TextBoxSectionCode').text('');
}
});

You could do the following way.
//Cache reference to DOM as DOM scan is expensive!
var textBox = $('#TextBoxSectionCode');
$('#CheckBoxSectionCode').click(function () {
//Use prop as opposed to attr
textBox.prop("readOnly", false).removeClass('disabled').addClass('abled').text("");
if ($(this).is(':checked')) {
textBox.prop("readOnly", true).removeClass('abled').addClass('disabled').text($("#TextBoxSectionName").val());
}
});

Can I determine what was clicked using JavaScript?

Once again I've inherited someone else's system which is a bit of a mess. I'm currently working with an old ASP.NET (VB) webforms app that spits JavaScript onto the client via the server - not nice! I'm also limited on what I can edit in regards to the application.
I have a scenario where I have a function that does a simple exercise but would also need to know what item was clicked to executed the function, as the function can be executed from a number of places within the system...
Say I had a function like so...
function updateMyDiv() {
$('#div1').hide();
$('#div2').hide();
$('#div13').show();
}
how could I get the ID (for example) of the HTML element that was clicked to execute this?
Something like:
function updateMyDiv() {
alert(htmlelement.id) // need to raise the ID of what was clicked,
$('#div1').hide();
$('#div2').hide();
$('#div13').show();
}
I can expand on this if neccessary, do I need to pass this as an arguement?

The this keyword references the element that fired the event. Either:
<element onClick="doSomething(this);">
or
element.onclick = function() {
alert(this.id);
}

Bind your click events with jQuery and then reference $(this)
$('.myDivClass').live('click', function () {
updateMyDiv(this);
});
var updateMyDiv = function (that) {
alert(that.id);
// save the world
};

You don't need to pass "this", it is assigned automatically. You can do something like this:
$('div').click(function(){
alert($(this).attr('id'));
})

Attach the function as the elements event handler is one way,
$(htmlelement).click(updateMyDiv);
If you are working with an already generated event, you can call getElementByPoint and pass in the events x,y coords to get the element the mouse was hovering over.

$('.something').click(function(){
alert($(this).attr('id'));
});

You would need to pass it the event.target variable.
$("element").click(function(event) {
updateMyDiv($(event.target));
});
function updateMyDiv(target) {
alert(target.prop("id"));
}

Where is your .click event handler? Wherever it is, the variable this inside of it will be the element clicked upon.
If you have an onclick attribute firing your function, change it to
<tag attribute="value" onclick="updateMyDiv(this)">
and change the JavaScript to
function updateMyDiv(obj) {
alert(obj.getAttribute('id')) // need to raise the ID of what was clicked,
$('#div1').hide();
$('#div2').hide();
$('#div13').show();
}

use the .attr('id') method and specify the id which will return what you need.

jQuery - How to get attribute of an element when using the 'click' event

I'm using jQuery to get a click on an 'a' element. I have a list of those links where each one has a class which by him I'm capturing the click.
I would like to know which of the links has been clicked (I have an attribute 'setid' for each link) and also get the point where the mouse has been clicked.
How could this be accomplished?
example of the code:
click me
$('.newItem').click(function (e) {
alert(e.attr('setid'));
});
EDIT:
OK, so to get the position I would use e.pageX

To use jQuery methods you have to wrap this with a call to jQuery.
$('.newItem').click(function () {
alert($(this).attr('setid'));
});

refer to the code given below:
document.getElementById("element_id").addEventListener("click",function(e)
{
console.log(e.srcElement.getAttribute("data-name"));
},false);

Like Skylar said in the comment to your question, you can use "data-" in front of your new attribute (which is HTML5 valid).
click me
Then in jQuery (v1.4.3+) you can get it like:
var setid = $(this).data("foo");
It's even a little nicer than attr() that other people have mentioned. See this for more examples - http://www.broken-links.com/2010/11/18/data-attributes-in-html-and-jquery/

You're on the correct path.
$(function(){
$('.newItem').click(function () {
alert( $(this).attr('setid') );
})
});

Your code is almost right to get the attribute. The only thing missing is wrapping this (a DOM element) in the jQuery wrapper so you can use jQuery functions. $(this).attr('setid') should work.
To get the page coordinates, use the pageX and pageY properties of the event object. So:
$('.newItem').click(function (e) { // e is the event object
alert($(this).attr('setid'));
alert(e.pageX);
alert(e.pageY);
});
See the documentation on the Event object.

Changing the onclick event delegate of an HTML button?

How do you change the JavaScript that will execute when a form button is clicked?
I've tried changing its onClicked and its onclicked child attributes like so:
$('mybutton').onClick = 'doSomething';
and
$('mybutton').attributes["onclick"] = 'doSomething()';
Neither seem to work. My other options are:
To have two buttons and hide one and show the other.
To have it directed to a function that evals a string and change the string to the function I want to execute.
Neither seem very elegant.
I'm using Prototype as a js library so it that has any useful tools I can use them.

If the original onclick event was set through HTML attributes, you can use the following to overwrite it:
$("#myButtonId").setAttribute("onclick", "myFunction();");

For Prototype, I believe that it would be something like this:
$("mybutton").observe('click', function() {
// do something here
});
EDIT: Or, as it says in the documentation, you could simply specify the function you want to call on click:
$('mybutton').observe('click', respondToClick);
function respondToClick(event) {
// do something here
}
But this is all, again, Prototype-specific.

Using the Prototype framework you can do:
Event.observe("mybutton", "click", clickHandler);
or:
Event.observe("mybutton", "click", function() {
alert("Button clicked!");
});
or:
$("mybutton").observe("click", clickHandler);
or:
$("mybutton").observe("click", function() {
alert("Button clicked!");
});
See the Event class documentation

The general way to set an onclick handler in javascript is to set onclick to a function, by passing it the name of a function directly, not in a string. So if myButton is set to a DOM Element, you would write:
myButton.onclick = doSomething;
So when you click the 'mybutton' button, the doSomething function will be called as doSomething(). For anonymous functions, you can write:
myButton.onclick = function() {
alert("myButton was clicked!");
};

In JQuery it's
$("#myButtonId").click(myFunction);
function myFunction(){
alert("Clicked");
}
Or if you want to put the function inline:
$("#myButtonId").click(function(){
alert("Clicked");
});
If you are using JQuery firstly make sure you use the relevant selector prefix (IE: If your using the Id of the element put a # in front of it). Secondly it's the click method to assign a callback to the click event.

Last I used Prototype, it was something like this:
Event.observe('mybutton', 'click', doSomething);
By the way, your examples might've even worked if you didn't quote the function names.
EDIT: Yes, Element.observe(element, eventName, handler) and someElement.observe(eventName, handler) also work. And don't quote the handler name - you want to pass the function not a string!

I found a solution for your issue with prototype under firefox:
$("#myButtonId").writeAttribute('onclick', ''); // first remove the attribute
$("#myButtonId").observe('click', function () { ... }); // then add the event