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How to make sure clickable objects don't propagate to the wrong element?

Languages involved: HTML, CSS, JS
Context: I'm relatively new to web development. I have two elements overlapping each other. One is a slider, one is a div. The slider is on top of the div.
Code snippets:
<div id="myDiv">
<input id="mySlider" type="range" min=1 max=100 step=1>
</div>
and
initListeners() {
document.getElementById("myDiv").addEventListener("click", divFunction);
document.getElementById("mySlider").addEventListener("input", sliderFunction);
}
I need to make it that when you click the slider, it doesn't click the div. How would I go about doing that? I've tried z-index, but that doesn't seem to change anything.
Thanks in advance!

As I'm sure you've figured out by now, events in JavaScript by default bubble up from a child to a parent. You need to stop that from happening at the child level, also known as preventing propagation.
Using the stopPropagation function, you can handle this as follows:
function sliderFunction(e) {
e.stopPropagation();
}
Simple. That event will no longer reach the parent.
EDIT
While stop propagation is the correct method to use, event listeners must also match in type. Therefore, both the slider and the parent DIV must have click event listeners (instead of input and click). stopPropagation stops propagation of a specific type of event.
function divFunction() {
console.log('DIV clicked!');
}
function sliderFunction(event) {
event.stopPropagation();
console.log('Slider clicked!');
}
function initListeners() {
document.getElementById('myDiv').addEventListener('click', divFunction);
document.getElementById('mySlider').addEventListener('click', sliderFunction);
}
initListeners();
/* unnecessary visual aides */
body *:not(label) {
padding: 2rem;
outline: 1px solid red;
position: relative;
}
label {
display: inline-block;
position: absolute;
background: #222;
color: #fff;
top: 0; left: 0;
}
<div id="myDiv">
<label>#myDiv</label>
<div id="tools">
<label>#tools</label>
<input type="range" id="mySlider">
</div>
</div>

You can also check the target once you fire that click event. I've used this approach before:
JSFiddle: http://jsfiddle.net/L4ck7ygo/1/
function divFunction(e) {
if (e.target !== this) {
return;
} else {
console.log('hit');
}
}
When the fiddle first loads, click the slider and you'll see the console log out some text. To see it work, remove the line that is being pointed to and rerun the fiddle. Now when you click the slider, you won't see anything logged in the console, but if you click on the div and not the slider, it will log to the console.
function initListeners() {
document.getElementById("myDiv").addEventListener("click", divFunction);
document.getElementById("mySlider").addEventListener("input", sliderFunction);
}
initListeners();
function divFunction(e) {
console.log('Firing...') // <-- This will log on any click
if (e.target !== this) {
return;
} else {
console.log('hit'); // <-- This will NOT log except for div click
}
}
function sliderFunction() {
console.log('Doing stuffs...');
}
<div id="myDiv">
<input id="mySlider" type="range" min=1 max=100 step=1>
</div>

UPDATE: Stupidity on my part. I had the ordering wrong for the elements which caused propagation to not act as intended.

calling different functions from inside and outside of div

I am having a div inside a div. And I want to call a function on the click of outer div and another function on the click of inner div. Is it possible to do so?
<div onclick="function1()">
<div onclick=function2()></div>
</div>

Yes, this is very much possible. And the code you have will get the job done.
NOTE: You need to add event.stopPropagation() in case you want to prevent the bubbling of the event from the inner function.
Try this out:
function function1() {
console.log("From outer div");
}
function function2(event) {
console.log("From inner div");
event.stopPropagation();
}
#outer-div {
width: 100px;
height: 100px;
background: yellow;
}
#inner-div {
width: 50px;
height: 50px;
background: red;
position: relative;
top: 25px;
left: 25px;
}
<div id="outer-div" onclick="function1()">
<div id="inner-div" onclick="function2(event)"></div>
</div>

Yes, it is; one way to do it is the way you've done it in your question, except:
You need quotes around the inner onclick attribute value, just as you have around the outer onclick attribute value.
You probably want to pass event into at least the inner one:
<div onclick="function2(event)"></div>
and then have it call stopPropagation on that:
function function2(event) {
event.stopPropagation();
}
so that the click event isn't propagated to the parent (doesn't bubble any further). If the click bubbles, function1 will be called as well.
Example:
function function1() {
console.log("function1 called");
}
function function2(event) {
event.stopPropagation();
console.log("function2 called");
}
<div onclick="function1()">
<div onclick="function2(event)">this div fires function2</div>
clicking here will fire function1
</div>
You might also consider modern event handling rather than onxyz-attribute-style event handlers; search for examples of addEventListener for details; my answer here also has a useful workaround for obsolete browsers.

Select <divs> within parent <div> using jQuery

I have a parent <div>, #amwcontentwrapper, which has a series of divs within it with their own classes and ids.
I want to use jQuery to select these child divs, and IF they have the class .amwhidden, do nothing, but if not, remove the .amwshown class and add the .amwhidden class.
This is what I have so far, but it is not working. I think it may be my selecting of the child divs within the parent.
Can anybody see any obvious problems? Thanks for your help.
if ($('#amwcontentwrapper > div').hasClass('amwhidden')){
} else {
$('#amwcontentwrapper > div').fadeIn(600, function(){
$('#amwcontentwrapper > div').removeClass('amwshown');
$('#amwcontentwrapper > div').addClass('amwhidden');
});
}
And here is the basic html that I am using:
<div class="amwshown" id="amwintro">
Intro Section, which should have the 'amwshown' class removed, and the
'amwhidden' class added, when the jQuery runs. Currently, this does not happen.
</div>
UPDATE: Using War10ck's solution in the comments below (i.e. $('#amwcontentwrapper > div.amwshown')) I have managed to get the classes changing as I wished. However, those which have had the .amwshown class removed and .amwhidden class added still show on the page, despite the CSS looking like this:
.amwhidden {
display:none;
}
.amwshown {
display:block;
}
Looking at the Dev Tools, it seems that, when the jQuery is run (on a click event) the classes are changing, but any classes which are having the .amwshown class added (thus displaying them on the page) are also having the a <style> tag added to them which makes them display:block;
When I then press another button, which should hide the aformentioned <div> to make way for another one, the class is being changed to .amwhidden, but that <style> tag is not being deleted, so even though it has the .amwhidden class, it is still on the page.
I've created a JSFiddle here, if anybody still wants to help!
`
$(document).ready(function() {
$('#buybutton').click(function() {
$('#amwcontentwrapper > div.amwshown').fadeIn(600, function() {
$(this).removeClass('amwshown').addClass('amwhidden');
});
if ($('#amwbuy').hasClass('amwshown')) {} else {
$('#amwbuy').fadeIn(600, function() {
$('#amwbuy').removeClass('amwhidden');
$('#amwbuy').addClass('amwshown');
});
}
});
$('#phdbutton').click(function() {
$('#amwcontentwrapper > div.amwshown').fadeIn(600, function() {
$(this).removeClass('amwshown').addClass('amwhidden');
});
if ($('#amwphd').hasClass('amwshown')) {} else {
$('#amwphd').fadeIn(600, function() {
$('#amwphd').removeClass('amwhidden');
$('#amwphd').addClass('amwshown');
});
}
});
});
#sidebar {
position: absolute;
left: 1%;
top: 1%;
font-size: 5em;
color: #000000;
width: 10%;
display: block;
background-color: red;
}
#amwcontentwrapper {
position: absolute;
left: 20%;
top: 5%;
}
.amwshown {
display: block;
}
.amwhidden {
display: none;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div id="amwsidebar">
<span class="sidebarbutton" id="phdbutton">PhD Button</span>
<br />
<br />
<span class="sidebarbutton" id="buybutton">Buy Button</span>
</div>
<div id="amwcontentwrapper">
<div class="amwshown" id="amwintro">
<p>An intro section to welcome the visitor. Disappears when one of the other sections is clicked.</p>
<br />
<br />
</div>
<div class="amwhidden" id="amwbuy">
Buy Section
</div>
<div class="amwhidden" id="amwphd">
PhD Section
</div>
</div>
`

You can use not to remove the elements you do not want, like this:
$('#amwcontentwrapper > div').not('.amwhidden')
.removeClass('amwshown')
.addClass('amwhidden');
And work with that.

Try this
$(document).ready(function() {
$("#amwcontentwrapper").children().each(function(elem, x) {
if ($(x).attr("class") == "amwhidden") {
alert($(x).attr("class"));
$(x).removeClass("amwhidden").addClass("amwshow");
alert($(x).attr("class"));
}
});
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.0/jquery.min.js"></script>
<div id="amwcontentwrapper">
<div class="amwhidden"></div>
<div></div>
<div></div>
</div>

You can try each as follow,
$("#amwcontentwrapper div").each(function(){
if($(this).hasClass('amwhidden'))
//DO something
else
//DO something
});

Thank you for all help, it has prompted some brainstorming which has solved this issue.
Instead of adding the .amwhidden class and removing the .amwhidden class using jQuery, I have just created a .amwsection class, which all the sections belong to which has an initial display value of none. So far, so good; all of the sections are not there when you load up the page.
Then I use the .css jQuery function to change the display:none to display:block when the corresponding button is clicked, and changing all other .amwsections to display:none. This works just fine, but the effect is quite abrupt; there is no fading in, as you would get if you used the .animate function. .animate, however, does not work with the display value.
.fadeOut and .fadeIn to the rescue! By wrapping the .css change in these, I can create a fading in/out effect and can still use the display value.
Here is one example of this code.
The #buybutton is the button to be pressed.
#amwintro is just something which appears when the page loads - it will now be set to display:none if this is the first button pressed.
The .amwsection are all of the hidden sections. This portion of the code just resets all of them. This and the #amwintro section happen very quickly (1/100th of a second) to keep response time good.
The #amwbuy is the specific section that I want to reveal. As you can see, this fades in over a longer period.
Currently only tested in Chrome, but I think I've got it!
$(document).ready(function () {
$('#buybutton').click(function() {
$('#amwintro').fadeOut(1, function() {
$(this).css({
display:'none',
});
});
$('.amwsection').fadeOut(1, function() {
$(this).css({
display:'none',
});
});
$('#amwbuy').fadeIn(600, function() {
$(this).css({
display:'block',
});
});
});
});

Prevent custom event from executing

I want to prevent custom event on parent when child is clicked. Note that I don't have access to the code of parent event. I've tried doing e.preventDefault() on the button itself but it doesn't help.
Is there any way of ignoring all parent events when something inside of it is clicked?
$(function(){
// Note that this is just an example, I don't have access to this code
// This is some custom event inside custom plugin
$('.container').on('click', function() {
alert('This should be alerted only if you click on green box');
});
$('.btn').on('click', function() {
// Here I want to make sure that *parent* events are not triggered.
alert('Button is triggered, green box should be not triggered');
});
});
.container {
width: 300px;
height: 200px;
background: green;
padding-top: 100px;
}
.btn {
width: 100px;
height: 100px;
display: block;
margin: auto;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div class="container">
<button class="btn">Click Me</button>
</div>

Since you're using jQuery, you can use the event.stopPropagation() method. The event.stopPropagation() method stops the bubbling of an event to parent elements, preventing any parent event handlers from being executed. You can see it in action here
$(document).ready(function () {
$("#button").click(function (event) {
alert("This is the button.");
// Comment the following to see the difference
event.stopPropagation();
});
$("#outerdiv").click(function (event) {
alert("This is the outer div.");
});
});
In this simple example, if you click on the button, the event is handled by its own handler and it won't bubble up the DOM hierarchy. You can add a very simple handler calling event.stopPropagation() on the button and it won't bubble up. No need to mess with the parent's JS.

click to change background toggle

When I click on it changes background. It works fine. But what if I want to click on it again to restore the original background? I have this code:
jQuery(document).ready(function($) {
$(".select").on("click", function () {
$(this).css("background-image", "url(images/selected.png)");
});
});
Here is jsfiddle EXAMPLE
Basically when I click on the div it changes the background, which is fine. But I want to have ability to click on it again to restore the original background.
It will be an alternative solution for tick box, but just for demo purposes.
Thanks

JS
replace
$(this).css("background-image", "url(images/selected.png)");
with
$(this).toggleClass("active");
Style
#multiselect .active {
background-image: url('...');
}
Fiddle http://jsfiddle.net/09xgrhxo/4/

Instead of using .css() to change the background-image I would add a class in your CSS and use .toggleClass().
Also be aware that simply adding a class will not be specific enough because your css is using:
#multiselect .select
you're going to have to target the class you add as a child of #multiselect:
#multiselect .change
CSS
#multiselect .change{
background-image: url(http://t2.gstatic.com/images?q=tbn:ANd9GcSZ51HqKXkejWAFcSBrodHd5eUN2QaIJro0jhN1YpmljSdQ5dj2)
}
JS
$(".select").on("click", function () {
$(this).toggleClass("change");
});
FIDDLE

You could use data-* attribute.
$('.select').attr('data-img', $('.select').css('background-image'));
$(".select").on("click", function() {
$(this).css("background-image", ($(this).css('background-image') == $(this).data('img')) ? "url(http://t2.gstatic.com/images?q=tbn:ANd9GcSZ51HqKXkejWAFcSBrodHd5eUN2QaIJro0jhN1YpmljSdQ5dj2)" : $(this).data('img'));
});
#multiselect .select {
background: url(http://t0.gstatic.com/images?q=tbn:ANd9GcQF_ErOlc78eOGZaEWb-dwPkrv2uyAoKx0Pbn3-e0tAZoUDSQRCsA) center;
width: 250px;
height: 100px;
margin-bottom: 20px;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
<div id="multiselect">
<div class="select">Option1</div>
<div class="select">Option2</div>
<div class="select">Option3</div>
</div>

Instead of writing background-img url in javascrpt, I would suggest to create two classes having same properties but different background-img url which you want to toggle. so here we will be toggling class (ultimately background-img) in javascript.
see jsfiddle [example][1]
[1]: http://jsfiddle.net/09xgrhxo/13/