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Javascript onclick menu change background colors

I have my menu like this:
https://jsfiddle.net/23r4q610/
And my code to change the selected menu button like below:
$('#bluebutton').click(function () {
$('.testul li').removeClass('selectedred selectedpurple selectedgreen selectedorange');
$('#bluebutton').addClass('selectedblue');
});
$('#redbutton').click(function () {
$('.testul li').removeClass('selectedblue selectedpurple selectedgreen selectedorange');
$('#redbutton').addClass('selectedred');
});
$('#purplebutton').click(function () {
$('.testul li').removeClass('selectedblue selectedred selectedgreen selectedorange');
$('#purplebutton').addClass('selectedpurple');
});
$('#greenbutton').click(function () {
$('.testul li').removeClass('selectedblue selectedred selectedpurple selectedorange');
$('#greenbutton').addClass('selectedgreen');
});
$('#orangebutton').click(function () {
$('.testul li').removeClass('selectedblue selectedred selectedpurple selectedgreen ');
$('#orangebutton').addClass('selectedorange');
});
Ofcourse this is bad code since it could be written much shorter. Should I go about this using just numbers so I can do some foreach, or is there a better way to do this?

This can be condensed by adding a generic click event on all buttons by using [id*="button"]. Then grab the relevant color from the nested anchor.
$('[id*="button"]').click(function(){
$('.testul li').removeClass();
$(this).addClass('selected'+$('a',this).attr('class'));
});
or
$('li').click.../*this would be the same as above*/
fiddle

In this particular case, there doesn't appear to be a good reason to add and remove classes. Just change the background color instead of adding and removing a class to do so.
$(this).css("background-color", "red");

I would avoid hard-coding the color names into the HTML IDs. Rather use a CSS class name like "selected" and describe in your CSS what that should look like. Example:
<li id="home-button" class="color-button">Home
CSS:
#home-button.selected,
#home-button:hover {
background: -webkit-linear-gradient(#78b1ff, #4881dc);
}
JS:
$('.color-button').click(function () {
$(this).toggleClass("selected").siblings(".color-button").removeClass("selected");
}
This way color information (presentation) is separated from semantic information (like "home") and JS code is daramtically shorter.
Note: this is just an advice, I have not tested it but should give you a good point to start.

You can reduce the code to only 1 click binding. Where when an element is clicked, class from all the li's is removed and then on the current clicked li, selected class is added.
$(".testul > li").click(function(){
$('.testul li').removeClass('selectedred selectedpurple selectedgreen selectedorange selectedblue');
var color = $(this).attr("id").replace("button","");
$('#'+color+'button').addClass('selected'+color);
});
Here is the updated fiddle - https://jsfiddle.net/23r4q610/2/

How to change CSS pseudo-class element using JavaScript

I want to change this image using javascript:
dance:active { background-image: url("myImage.png") }
You can use
document.getElementById(element).style.backgroundImage = url(image);
to change
#element {background-image: url(image)}
I would like to change the image of when the element is active using javascript. Thanks!

I figured it out!
You can have multiple classes in your CSS :
element.dance1 { stuff }
element.dance1:active { active stuff }
element.dance2 { stuff 2 }
element.dance2:active { active stuff 2 }
and then change the class of the element in javascript:
document.getElementById(element).className = dance1/dance2

You can try using jQuery to achive what you want. dance: active is CSS Pseudo-classes. Learn more about Pseudo-class.
The demo change the div color when mouse down and switch the color back when mouse up. Leave comments if this is not what you want.
$("#dance").on("mousedown", function () {
$("#dance").css("background", "blue");
}).on("mouseup", function(){
$("#dance").css("background", "black");
});
https://jsfiddle.net/x_li/5nkvms8q/
and jQuery can also do the following
$('#damce:checked').val();

CSS get parent elements attribute

So i just ran into this problem. Let's say I have the following markup:
<article data-color='#123456'>
<header>...</header>
<a href='#'>Lorem ipsum</a>...
...
</article>
So I have an element with a custom color attribute. I want to have the header have it as a background color, and the link as a color (the color is either randomly generated or user-defined). Is there a way to do this is CSS alone? (I am aware that jQuery would do this without a problem, but I'd like to kepp things as pretty as possible, not using Javascript for styling alone.)

You can use an attribute selector in your CSS:
article[data-color="#123456"] header {
background-color: "#123456";
}
article[data-color="#123456"] a {
color: "#123456";
}
However, this assumes you can enumerate the data-color attributes in your CSS. If it's generated dynamically and can take any value, you can't do it in CSS -- it doesn't have variables or back-references.

Unfortunately CSS cannot do this. the JS is relatively simple though:
$('article').filter(function() {
return $(this).data('color');
}).each(function() {
var $el = $(this), color = $el.data('color');
$el
.find('header').css('background-color', color).end()
.find('a').css('color', color);
});
Example fiddle

I think you can do it like this:
article[data-color="#123456"] header {
background-color: attr(data-color color);
}
article[data-color="#123456"] a {
color: attr(data-color color);
}
UPDATE
The first answer is incorrect, it doesn't work.
Do this rather:
article[data-color="#123456"] header {
background-color: "#123456";
}
article[data-color="#123456"] a {
color: "#123456";
}

Alternate colors on click with jQuery

I'm sure there is a simple solution to this, and I'm sure this is a duplicate question, though I have been unable to solve my solution particularly because I don't really know how to phrase it in order to search for other questions/solutions, so I'm coming here hoping for some help.
Basically, I have spans with classes that assigns a background-color property, and inside those spans are words. I have three of these spans, and each time a user clicks on a span I want the class to change (thus changing the background color and inner text).
HTML:
<span class="alternate">
<span class="blue showing">Lorem</span>
<span class="green">Ipsum</span>
<span class="red">Dolor</span>
</span>
CSS:
.alternate span { display : none }
.alternate .showing { display : inline }
.blue { background : blue }
.green { background : green }
.red { background : red }
jQuery:
$(".alternate span").each(function() {
$(this).on("click", function() {
$(this).removeClass("showing");
$(this).next().addClass("showing");
});
});
This solution works great using $.next until I get to the third click, whereafter .showing is removed, and is not added since there are no more $.next options. How do I, after getting to the last-child, add .showing to the first-child and then start over? I have tried various options including if($(".alternate span:last-child").hasClass("showing")) { etc. etc. }, and I attempted to use an array and for loop though I failed to make it work.
Newb question, I know, but I can't seem to solve this so as a last resort I'm coming here.

try this:
$(".alternate span").each(function() {
$(this).on("click", function() {
$(this).removeClass("showing");
if($(this).is(":last-child"))
$(".alternate span:first-child").addClass("showing");
else
$(this).next().addClass("showing");
});
});
http://jsfiddle.net/NPx2x/

Check this, and also it performs faster. .next() returns undefined if no element found.
$(".alternate span").on("click", function() {
$(this).removeClass("showing");
var next = $(this).next();
next.length ? next.addClass("showing") : $("span.blue").addClass("showing");
});

Dynamically changing cursor/setting cur files

How can I dynamically change the style of cursors on my div using JS or CSS?
Because I have multiple situations...
I've tried the code below:
div.addEventListener("mouseover", function(evt) {
if (tool == "BC"){
div.style.cursor = "url(/icons/bc.cur)";
}
if (tool == "pan"){
div.style.cursor = "url(/icons/pan.cur)";
}
}

Assuming you're using conditional comments as in html5 boilerplate you could define this style (note the different syntax for newer browser — see MDN docs for further information):
div.bc { cursor : url(/icons/bc.cur), auto; }
div.pan { cursor : url(/icons/pan.cur), auto; }
/* style for IE<9 */
.lt-ie9 div.bc { cursor : url(/icons/bc.cur); }
.lt-ie9 div.pan { cursor : url(/icons/pan.cur); }
and, assuming for simplicity that your div hasn't any class applied, just change your js code like so:
div.addEventListener("mouseover", function(evt) {
this.className = tool.toLowerCase();
}
This approach will ensure good scalability, since in case you have another cursor to list, the javascript doesn't need to be modified further, just add a new couple of css rules. Furthermore you will totally keep off css from javascript, thus your javascript has a better mantainability.