i am trying to make a colour change when a button is clicked and i managed to do this however i want to change the colour of not just the main content container but more containers how do i do this?
function changeblackandwhite(objDivID) {
if(document.getElementById(objDivID).style.color=='black'){
document.getElementById(objDivID).style.color='white';
document.getElementById(objDivID).style.backgroundColor='black';
}
else if(document.getElementById(objDivID).style.color=='white'){
document.getElementById(objDivID).style.color='black';
document.getElementById(objDivID).style.backgroundColor = 'white';
}
else{
document.getElementById(objDivID).style.color='black';
document.getElementById(objDivID).style.backgroundColor='white';
}
}
<img src="images/colour.jpg" title="Change Text/Backgroud Colors">
There are dozens of ways you can accomplish this.
You could change the argument of your function to be an array of strings. You could also reduce the complexity of your function as well
<script type="text/javascript">
changeblackandwhite = function() {
for( var idx=0; idx < arguments.length; idx++) {
var tgtDiv= document.getElementById(arguments[i]);
if(tgtDiv.style.color=='black'){
tgtDiv.style.color='white';
tgtDiv.style.backgroundColor='black';
}
else{
tgtDiv.style.color='black';
tgtDiv.style.backgroundColor='white';
}
}
};
</script>
<img src="images/colour.jpg" title="Change Text/Backgroud Colors">
As another reader questioned - you can do this with jQuery in a single line.
With jQuery, you can declare the elements in question to have a class attribute.
Using jQuery, you can then do something like:
$('div.someClass').css({'color': 'black', 'background-color': 'white'});
The argument to jQuery can be a class based selector, an id based selector, or any other selector you choose.
If you are open to jquery and you assign 1 class in common with these two divs you can do the following:
This should get you started (see this jsfiddle): I changed the fiddle to include a neater solution where clicking on the button adds and removes classes on the containers which allows you to set multiple attributes including the text color in one quick call.
<div class='container'>
</div>
<div class='container'>
</div>
<button id="changeColor" type="button">Change Color </button>
<script type="text/javascript">
$(document).ready( function() {
$('#changeColor').click( function() {
if ($('.container').hasClass("blackContainer")){
$('.container').addClass("whiteContainer");
$('.container').removeClass("blackContainer");
} else {
$('.container').removeClass("whiteContainer");
$('.container').addClass("blackContainer");
}
});
});
</script>
//CSS
.blackContainer {
background-color: black;
color: white;
}
.whiteContainer {
background-color: white;
color: black;
}
I made a jsfiddle for you to play around with jsfiddle
I also did the javascript/jQuery in a similar way as the OP since it usually helps them understand.
As stated above, there are several different ways to do this, I've done but one.
The document.ready function sets up an event listener for the object to be clicked, most of the time this is how you'll see events coded. So when the link is clicked, it calls the function with the string name of the object the listener is for.
$(document).ready(function() {
$("#changeit").click(function(){
changeblackandwhite("Maincontainer");
})
});
After the event listener is assigned, it will call the function below when the link is clicked on.
// Here's your function, put the current color in a var, check if it's black
// if black, change colors, else make it black.
function changeblackandwhite(objDivID) {
var curColor = $("#" + objDivID).css("color");
if( curColor == 'rgb(0, 0, 0)'){
$("#"+objDivID).css({'color':'white','background-color':'black'});
} else {
$("#"+objDivID).css({'color':'black','background-color':'ghostwhite'});
}
}
Related
I have a site with a lot of different div. The thing they have in common is all share (besides their unique classes) a shared class. Lets just call it .changeClass.
What I am looking for is code with a button (or radio buttons) and by clicking the button, the background instance of all these divs will get the same one (which the .changeClass has). So the .changeClass will just be active when the button is toggled/clicked.
I am looking for a way to do this with pure javascript and no Jquery.
Sorry for being a noob :-)
In the solution below, clicking the <button> element will add/remove the class style .changeClass to all elements that have the class style .apply applied.
let button = document.getElementById('change');
let containers = document.getElementsByClassName('apply');
function changeButtonText() {
if(button.innerHTML === "Add")
button.innerHTML = "Remove";
else
button.innerHTML = "Add";
}
button.addEventListener('click', function() {
for(let index = 0 ; index < containers.length ; ++index)
containers[index].classList.toggle('changeClass');
changeButtonText();
});
div {
margin-top: 25px;
}
.apply {
border: 3px solid black;
}
.changeClass {
background-color: black;
color: white;
border: 3px solid red;
margin-top: 25px;
}
<button id="change">Add</button>
<div class="apply">1</div>
<div class="apply">2</div>
<div class="apply">3</div>
<div class="apply">4</div>
<div class="apply">5</div>
First lets get all divs that are on the DOM
const divs = document.getElementsByTagName("div");
You will have array of all the divs that are on the DOM. Then add your class to all of it. In order to do that, lets loop it.
divs.forEach(div => div.className += div.className + " changeClass");
Could this be what you are looking for?
In html:
<button onclick="changeColor('blue');">blue</button>
In JS
function changeColor(newColor) {
var elem = document.getElementsByClassName("changeClass");
elem.style.color = newColor;
}
The HTML color can be any color you would like it to be, just change they name from blue to any color or input a hex code.
We have multiple divs with the same class value
We have given a function to the button that we want the event to happen when it is clicked, using the onclick method. Now when we click the button, the function called myFunction will run.
HTML:
<div class="changeClass">Im Example Div</div>
<div class="changeClass">Me Too</div>
<button type="submit" onclick="myFunction()">Click To Change Div BgColors !
</button>
We must define myFunction as Javascript and change the background color.
We have defined a function called myFunction.
With the getElementsByClassName selector in our function, we got all the data with the class value changeClass in object format.
To add a background (or any css property) to all of these objects; We put the object in a for loop and now we split our elements.
We can now define a background color for our elements with the style.backgroundColor parameter.
JavaScript:
function myFunction(){
var divs = document.getElementsByClassName('changeClass');
for(var i=0; i< divs.length; i++){
divs[i].style.backgroundColor = 'red';
}
}
For more detailed information, you can refer to the resources: https://www.w3schools.com/jsref/met_document_getelementsbyclassname.asp
Don't be sorry for being new at something and wanting to learn more!
So what you are saying is that the divs you want to change all have a common class of "changeClass". If this is the case then you want a function is passed an argument value of the color you want to be changed. Since all of your divs are static and you probably don't plan on changing, declare a variable outside of this function that has the following code
const divs = document.getElementsByClassName("changeClass")
Then, inside of the function, loop through all of the divs collected inside the variable "divs", or whatever you want to call it. Since "getElementsByClassName" returns a collection, it does not have the built in "foreach" and "map" methods. So you have to use a for loop preferably the following.
const divs = document.getElementsByClassName("changeClass");
function changeColor(color) {
for (let element of divs) {
element.style.backgroundColor = color;
}
}
I may have interpreted this wrong but I hope it helps
You may find using a CSS variable helpful.
For example:
function bg(color) {
document.body.style.setProperty('--bg', color);
}
body {
--bg: cyan;
}
.container {
display: flex;
gap: 1vw;
}
.container div {
width: 100px;
height: 100px;
background-color: black;
}
.container div.changeClass {
background-color: var(--bg);
}
<body>
<button onclick="bg( 'red');">Red</button>
<button onclick="bg( 'green');">Green</button>
<button onclick="bg( 'blue');">Blue</button>
<button onclick="bg( 'black');">Black</button>
<div class="container">
<div class="changeClass"></div>
<div class="changeClass"></div>
<div class="changeClass"></div>
<div></div>
<div class="changeClass"></div>
</div>
</body>
Then when one of the radio buttons is clicked it sets the variable --bg.
Here's a simple snippet:
First of all - thank you for all your replies. And yes I should have included code. I tried so many things that i just gave up at som point - got confused what was right code and what was just rubbish. So I appreciate so much that you all took time to answer me. This was my first post so now I know for the future. The answers I got all was possible ways to solve my problem - so thank you all. I will do better next time. You are awesome...
BTW - All solutions seems to work - but can only checkmark one of them as you know.
You can add or remove a class to change the colours of different div:
document.queryselector('.className').classList.add('classNamethatyouwanttoadd');
document.queryselector('.className').classList.remove('classNamethatyouwanttoadd');
I will need to put 2 different actions on a single link which would have an active/inactive state, right now I only know how to do one at the time, something like this (active):
State One
And I would like to have another one on same click (inactive), is there a way to have this dynamically changed? The label shouldn't change, except for color for example - style.
On the other side, it would be a great thing if I could show the list of active items as well, something like:
Active states: State one, State two, State ...
I recommend something other than an A tag for what you're doing. I also recommend the modern equivalent of an onclick, an event listener. I also recommend assigning and toggling the class.
State One
I have removed your onclick and put it into an event listener. I've added a class, so you can toggle it.
function classToggle() {
this.classList.toggle('class123');
this.classList.toggle('class456');
}
This toggles your class, thus allowing you to change the behavior of the link based on the class. Active/Inactive or Class123/Class456 whatever you want to use will work.
document.querySelector('#myDiv').addEventListener('click', classToggle);
This is your listener. It applies the classToggle function on click. You can do this with a div/button/whatever. Personally I'd change the A tag to a Div.
<div id="myElem" class="class123">click here</div>
And here is an example of this stuff working and changing based on the toggle and classes.
function classToggle() {
this.classList.toggle('class123');
this.classList.toggle('class456');
}
document.querySelector('#myElem').addEventListener('click', classToggle);
document.querySelector('#myElem').addEventListener('click', mogrify);
function mogrify(){
if (document.querySelector('#myElem').classList.contains('class123')) {
document.querySelector('#myElem').style.backgroundcolor = "#54C0FF"
document.querySelector('#myElem').innerText = "State Two";
} else {
document.querySelector('#myElem').style.backgroundcolor = "#FF8080"
document.querySelector('#myElem').innerText = "State One";
}
}
.class123 {
color: #f00;
}
.class456 {
color: #00f;
}
State One
I think I got it to work, here's my code, please let me know if good enough.
A href:
State One
js:
<script>
function toggleState(a) {
if ( a.className === 'visible' ) {
HideOneState('state_One', gameInstance);
a.className = '';
} else {
ShowOneState('state_One', gameInstance);
a.className = 'visible';
}
}
</script>
#shandoe2020 has a good answer but here is the "old way" which is pretty easy to understand too. It can be adapted to links (or anything else) quite easily.
<!DOCTYPE html>
<html>
<head>
<style>
.my-button { width:150px; height:150px; }
.my-red { background-color:#ff0000; }
.my-blue { background-color:#0000ff; }
</style>
<script>
/* toggle the state of my-red and my-blue class */
function toggle()
{
/* yeah yeah, hardcoding the item to change is bad */
var elem = document.getElementById("btn")
elem.classList.toggle("my-red")
elem.classList.toggle("my-blue")
}
</script>
</head>
<body>
<div>
<p><button id="btn" class="my-button my-red" onclick="toggle()">Button</button></p>
</div>
</body>
</html>
Goal
In my program I want to do both things with jquery/javascript:
Change styling of css classes dynamically
Add/remove classes to elements
Problem
To do the first thing I use $(".className").css() method, but it changes style only for those elements that already have className class, i.e. if I later add className to an element its style won't be new. How can I solve this?
Example
See it also at jsfiddle.
$("p").addClass("redclass");
$(".redclass").css("color", "darkRed");
$("span").addClass("redclass");
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<p>I want to be red! And I am.</p>
<span>I want to be red too but I'm not :'(</span>
Result:
A more shorten format:
$("<style/>", {text: ".redclass {color: darkRed;}"}).appendTo('head');
The snippet:
$("<style/>", {text: ".redclass {color: darkRed;}"}).appendTo('head');
$("p").addClass("redclass");
$("span").addClass("redclass");
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<p>I want to be red! And I am.</p>
<span>I want to be red too but I'm not :'(</span>
While other (working) answers have been supplied, they don't actually answer your question - namely, they don't change the specified css class, but instead override it by adding another rule later in the document.
They achieve this, basically:
Before
.someClass
{
color: red;
}
After
.someClass
{
color: red;
}
.someClass
{
color: white;
}
When in many cases, a better option would see the color attribute of the existing rule altered.
Well, as it turns out - the browser maintains a collection of style-sheets, style-sheet rules and attributes of said rules. We may prefer instead, to find the existing rule and alter it. (We would certainly prefer a method that performed error checking over the one I present!)
The first console msg comes from the 1 instance of a #coords rule.
The next three come from the 3 instances of the .that rule
function byId(id){return document.getElementById(id)}
window.addEventListener('load', onDocLoaded, false);
function onDocLoaded(evt)
{
byId('goBtn').addEventListener('click', onGoBtnClicked, false);
}
function onGoBtnClicked(evt)
{
alterExistingCSSRuleAttrib('#coords', 'background-color', 'blue');
alterExistingCSSRuleAttrib('.that', 'color', 'red');
}
// useful for HtmlCollection, NodeList, String types (array-like types)
function forEach(array, callback, scope){for (var i=0,n=array.length; i<n; i++)callback.call(scope, array[i], i, array);} // passes back stuff we need
function alterExistingCSSRuleAttrib(selectorText, tgtAttribName, newValue)
{
var styleSheets = document.styleSheets;
forEach(styleSheets, styleSheetFunc);
function styleSheetFunc(CSSStyleSheet)
{
forEach(CSSStyleSheet.cssRules, cssRuleFunc);
}
function cssRuleFunc(rule)
{
if (selectorText.indexOf(rule.selectorText) != -1)
forEach(rule.style, cssRuleAttributeFunc);
function cssRuleAttributeFunc(attribName)
{
if (attribName == tgtAttribName)
{
rule.style[attribName] = newValue;
console.log('attribute replaced');
}
}
}
}
#coords
{
font-size: 0.75em;
width: 10em;
background-color: red;
}
.that
{
color: blue;
}
<style>.that{color: green;font-size: 3em;font-weight: bold;}</style>
<button id='goBtn'>Change css rules</button>
<div id='coords' class='that'>Test div</div>
<style>.that{color: blue;font-size: 2em;font-weight: bold;}</style>
#synthet1c has described the problem. My solution is:
$("head").append('<style></style>');
var element = $("head").children(':last');
element.html('.redclass{color: darkred;}');
What you are having issue with is that when you use the jQuery selector $('.redclass').css('color', 'darkRed') you are getting all the elements that currently have that class and using javascript to loop over the collection and set the style property.
You then set the class on the span after. Which was not included in the collection at the time of setting the color
You should set the class in your css file so it is distributed to all elements that have that class
console.log($('.redclass').length)
$("p").addClass("redclass");
console.log($('.redclass').length)
// $(".redclass").css("color", "darkRed");
$("span").addClass("redclass");
console.log($('.redclass').length)
.redclass {
color: darkRed;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<p>I want to be red! And I am.</p>
<span>I want to be red too but I'm not :'(</span>
The below code takes into account different tags and turns the background red if the tag is clicked on. I want to code it so that if it is clicked on again, it changes back from red and 'deletes' the background, or at least set it to null. I have tried an if statement to no avail. I know that I can just make another click event that changes the background to white, but this is for experimental purposes and i was wondering if this CAN be done with if statements. thanks to ya.
<script>
$(document).ready(function() {
$("p, h1").click(function() {
$(this).css("background-color", "red");
if ($(this).css("background-color", "red")) {
$(this).css("background-color", "null");
}
});
});
</script>
First you need to use the getter version of .css() like
if($(this).css("background-color") == "red"){
but it still won't work because, the css getter will return a rgb format value and will return non consistent values across browsers.
So the solution is to use a css based solution using toggleClass()
.red {
background-color: red;
}
then
$(document).ready(function() {
$("p, h1").click(function() {
$(this).toggleClass("red");
});
});
Demo: Fiddle
$('p, h1').click(function() {
var $this = $(this);
var altColor = $this.data('altColor');
$this.css('background-color', altColor ? '' : 'red');
$this.data('altColor', ! altColor);
});
This answers your question, but you should really be using a CSS class for this.
This is easily done using CSS, and is a bit more straight forward. If you create a CSS class for the click, then you can just toggle it on/off each time the item is clicked:
CSS
p, h1 {
background-color: none;
}
p.red, p.h1 {
background-color: red;
}
JavaScript:
$('p, h1').click(function() {
$(this).toggleClass('red');
});
So I set the color of the <body> with:
body
{
color:Black;
}
within the <head> and <style> tags,
and then I've got various elements in the body, for which if I click them, they call a function. i.e.
<p id="CSE1020" onclick="prereq(this)">CSE1020</p>
The prereq function is as follows:
function prereq(code) {
if (code.style.color != "black") {
code.style.color = "black";
code.style.fontWeight = "normal";
}
}
And otherwise, if the element is already black, I change the color.
The problem/question is: I have to click the element twice before it changes color.
In other words, its not 'black' initially. The if statement is executed, even though the default color, before it is clicked should be black. How do I get it to recognize that when I first click the element, that it's 'black'?
Is jQuery an option? If it is you could do this:http://jsfiddle.net/CxayY/
$('#CSE1020').on('click', function(){
if($('body').css('color')!='black')
{
$('body').css('color','black');
$('body').css('font-weight','normal');
}
});
Try searching in CSSRules:
function prereq(code) {
var cssRules = window.getMatchedCSSRules(code);
...
}
So, it works when I add the style to the element itself, i.e.
<p id="CSE1020" style="color:black" onclick="prereq(this)">CSE1020</p>