I have this code in JavaScript:
function change() {
document.getElementById("mem").className = 'gif';
}
The fig and gif are like this:
a.fig {
background: #FFFFFF;
}
a.gif {
background: #000099 ;
}
and the function is used like this
<a class ="fig" id ="mem" onClick="javascript:change()" href="users" >
Where the only difference between gif and fig in CSS is that they have different background colors. The problem is that the change is only noticeable in just a second and it is not permanent!
Any ideas?
HTML:
<a id="mem" class="fig" href="users"> MEMBERS </a>
JavaScript:
var a = document.getElementById('mem');
a.onclick = function() {
this.className = this.className == 'fig' ? 'gif' : 'fig';
}
Live demo: http://jsfiddle.net/eVQjB/
Note: in the demo, I return false; from the click handler to prevent the anchor from being activated.
function change() {
var mem = document.getElementById("mem");
if (mem.className == 'fig') {
mem.className = 'gif';
}
else {
mem.className = 'fig';
}
}
You may be looking for a different problem with JavaScript and styles, but if I understand your problem, you'll still need a different color for the anchor if it has been visited. You can let CSS do that for you:
#mem {
background: #FFF;
}
#mem:visited {
background: #009;
}
<a id="mem" href="users">Lead me to the promised land!</a>
you can try by following way
document.getElementById("idElement").setAttribute("class", "className");
IF still not working you r class is not chaning the style of your html element
Just add return false:
onClick="change(); return false;"
The thing is that without it, the class is changed then the page is redirected as this is the default behavior of anchor tag.
If you want to reload the page and change the class in the reloaded page, have such link:
href="?change=true"
Then in the server side code check for this flag and if true put different class. I'm not familiar with PHP but here is classic ASP version, hopefully similar enough to PHP:
<%
Dim sClassName
If Request("change")="true" Then
sClassName = "gif"
Else
sClassName = "fig"
End If
%>
<a class ="<%=sClassName%>" id ="mem" href="?change=true">
Related
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>
So I'm trying to make a code that allows me to change the image once I hover over it.
The initial code works. But I have 72 other images to go through with this feature. I'm trying to call each one individually so I don't have to repeat so much code.
I want a simple html code like
<img id="seal" src="img/seal/dantalion.png" onmouseover="rollover(dantalion)"
onmouseout="rollaway(dantalion)" />
<img id="seal" src="img/seal/vassago.png" onmouseover="rollover(vassago)"
onmouseout="rollaway(vassago)" />
Here is the code that works.
function rollover(img) {img.src = "img/seal/hover/vassago.png";}
function rollaway(img) {img.src = "img/seal/vassago.png";}
Here is what I want to do. Keep in mind please, I'm new to this sort of thing.
function rollover() {
dantalion.src = "img/seal/hover/dantalion.png";
vassago.src = "img/seal/hover/vassago.png";
}
function rollaway() {
dantalion.src = "img/seal/dantalion.png";
vassago.src = "img/seal/vassago.png";
}
How do I individually call the object in the HTML code?
This is a simple solution to your problem. On mouseover of the wrapper div #images we check if you are hovering an image and if so, update the image src with the hover url.
On mouseout or if you hover on a different image the images are reset back to the original src
var images = document.getElementById('images');
var prevEl;
function resetImages() {
if (prevEl) {
prevEl.src = prevEl.src.replace('/hover', '');
prevEl = null;
}
}
images.addEventListener('mouseover', function(e) {
resetImages();
if (e.target && e.target.nodeName == "IMG") {
prevEl = e.target;
e.target.src = e.target.src.replace('/seal', '/seal/hover');
}
});
images.addEventListener('mouseout', resetImages);
<div id="images">
<img src="img/seal/dantalion.png">
<img src="img/seal/vassago.png">
</div>
Here's an example using event delegation. I've tried to use only core JS APIs because you didn't mention any libraries but if you were using a library there's a good chance it would be able to do some of this for you.
document.body.addEventListener('mouseover', function(ev) {
var target = ev.target,
cls = target.classList;
if (!cls.contains('seal')) {
return;
}
cls.add('seal-over');
target.innerHTML = target.innerHTML.replace('/seal/', '/seal/hover/');
});
document.body.addEventListener('mouseout', function(ev) {
var target = ev.target,
cls = target.classList;
if (!cls.contains('seal')) {
return;
}
cls.remove('seal-over');
target.innerHTML = target.innerHTML.replace('/hover', '');
});
.seal {
border: 1px dotted #777;
height: 70px;
margin: 10px;
width: 200px;
}
.seal-over {
background: #eee;
}
<div class="seal">img/seal/dantalion.png</div>
<div class="seal">img/seal/vassago.png</div>
While my example changes the innerHTML you would change the src instead - I didn't have your images so I couldn't easily use img tags. The id attribute has to be unique so I've changed it to using a class instead. Adding the seal-over class isn't required, I just thought it made the example more interesting: you'd probably use a CSS :hover pseudo-class for that if this were real code.
One of many guides to delegation, you can find others with a quick search online:
https://davidwalsh.name/event-delegate
The idea is to add a single listener on an element higher up the tree. Events propagate up so you can react to events on descendent elements. The event target refers to the element on which the actual event occurred. The code checks whether this element is one of the elements we care about and then makes the changes accordingly.
According to This page I was able to remove all the CSS preloaded and added on the webpage using that. I wanted to implement a button system where "onclick" = enable/disable webpage CSS even the ones pre-loaded by my web-host. I would like to eliminate the style tags to prevent lags for my website users. I prefer using the script that I have linked above unless there is another alternative that works better. Is it possible to enable CSS onclick the same button to disable? If not is it possible, can it be done with this quick? example with the preferred script below:
if (disable) {
style = "disable";
} else {
location.reload();
}
PREFERRED SCRIPT:
function removeStyles(el) {
el.removeAttribute('style');
if(el.childNodes.length > 0) {
for(var child in el.childNodes) {
/* filter element nodes only */
if(el.childNodes[child].nodeType == 1)
removeStyles(el.childNodes[child]);
}
}
}
removeStyles(document.body);
What about a different aproach?
Add initially a class to a body called 'styled' for example
<body class="styled">
use it as a main selector in your css definitions
<style>
.styled a { ... }
.styled h1 { .... }
</style>
then an example jquery script to toggle the class:
<script>
$(function() {
$('#myswitch').click(function() {
$('body').toggleClass('styled');
});
});
</script>
when class is present, the page will be styled, when absent there will be no styling.
Of coures there could be better aproach, but this is the first thing which pops up in my mind
To remove all style on an element, you could do
function removeStyles(el) {
el.style = {};
}
If you want to enable/disable the CSS on the page, then the goal is not to merely remove all the styles on the page, but you will need to save them somewhere also so they can be recalled when the user re-clicks the button. I would recommend having jQuery to help you with this, and it could be done the following way:
var style_nodes = $('link[rel="stylesheet"], style');
style_nodes.remove();
$('*').each(function(num, obj) {
var style_string = $(obj).attr("style");
if (style_string) {
$(obj).data("style-string", style_string);
$(obj).attr("style", "");
}
});
Now you've saved the stylesheets and style DOM nodes inside of style_nodes, and the actual style attribute inside of a jQuery data attribute for that specific DOM node. When you click to add the CSS back to the page, you can do the following:
$('head').append(style_nodes);
$('*').each(function(num, obj) {
if ($(obj).data("style-string"))
$(obj).attr("style", $(obj).data("style-string"));
});
Check out this JS Fiddle I put together to demonstrate it:
https://jsfiddle.net/5krLn3w1/
Uses JQuery, but I'm sure most frameworks should give you similar functionality.
HTML:
<h1>Hello World</h1>
Turn off CSS
Turn on CSS
JS:
$(document).ready(function() {
$('a#turn_off').click(function(evt) {
evt.preventDefault();
var css = $('head').find('style[type="text/css"]').add('link[rel="stylesheet"]');
$('head').data('css', css);
css.remove();
});
$('a#turn_on').click(function(evt) {
evt.preventDefault();
var css = $('head').data('css');
console.info(css);
if (css) {
$('head').append(css);
}
});
});
CSS:
body {
color: #00F;
}
h1 {
font-size: 50px;
}
I am working on a class project and need to be able to toggle the background color of a transparent png on click. I have been working through a number of examples from the site, but I can't get it working. I am a total novice at Javascript and haven't had luck trying to plug in jQuery code either.
Here is the targeted section:
<div class="expenseIcon"><a href="#">
<img src="images/mortgage.png"></a><br/>
<p>Rent or Mortgage</p>
</div>
On clicking the linked image, the goal is for the background on the image to change to green. Clicking it again would change it back to the default, white. Here's the CSS I'd like to toggle on/off with click.
.colorToggle {
background: #A6D785;
}
I had tried adding class="iconLink" to the href and class="iconBox" to the image with the following Javascript adapted from another post, but it didn't work.
var obj = {};
$(document).ready(function () {
$(".iconLink").click(function () {
var text = $(this).find(".iconBox");
obj.var1 = text;
//alert(obj.var1);
//return false;
$('.iconBox').removeClass('colorToggle');
$(this).addClass('colorToggle')
});
});
Any advice would be greatly appreciated!
Let's break down what is happening with your current code when you click the link.
var obj = {};
$(document).ready(function () {
$(".iconLink").click(function () {
var text = $(this).find(".iconBox");
obj.var1 = text;
$('.iconBox').removeClass('colorToggle');
$(this).addClass('colorToggle')
});
});
JQuery finds all elements with the classname "iconBox". In your case, this is the img element. The reference to that element is then saved in "obj.var1". You do not end up doing anything with this reference, so these two lines can be removed.
All elements with the class "iconBox" have the class "colorToggle" removed. Your img element didn't have this class on it, so nothing happens.
The class "colorToggle" is added to the anchor element. Yes! Now the element wrapping the img has a background color.
Unfortunately, clicking the anchor tag again won't do anything, since the anchor tag will already have the "colorToggle" class and all we would be doing would be trying to add it again. Hmm. Let's try changing addClass to toggleClass. Here's our new code:
$(document).ready(function () {
$(".iconLink").click(function () {
$(this).toggleClass('colorToggle');
}
});
Also, note that because we're working with the anchor element, the p element won't be affected by this change. If you want the entire div to change background colors, use this line instead:
$(".expenseIcon").toggleClass('colorToggle');
Using the given markup:
<!-- to toggle the bg-color onClick of anchor tag -->
<div class="expenseIcon">
<a href="#">
<img src="images/mortgage.png">
</a>
<br/>
<p>Rent or Mortgage</p>
</div>
since the question asks for javascript, heres an option for updating the background-color of an element using the built-in js.style method
//get a handle on the link
//only one element w/ className 'expenseIcon'
//first child of 'expenseIcon' is the anchor tag
var link = document.getElementsByClassName('expenseIcon')[0].children[0];
//get a handle on the image
var image = link.children[0];
//listen for click on link & call bgUpdate()
link.addEventListener('click', bgUpdate, false);
function bgUpdate() {
if(image.style.backgroundColor === 'lightgoldenrodyellow'){
image.style.backgroundColor = 'aliceblue';
} else if (image.style.backgroundColor === 'aliceblue') {
image.style.backgroundColor = 'lightgoldenrodyellow';
}
else console.log('image bgColor: ' + image.style.backgroundColor);
}
a similar example
css
.expenseIcon{
background: red;
}
.colorToggle {
background: blue;
}
jquery
$(".expenseIcon").click(function () {
$('.expenseIcon').toggleClass('colorToggle');
});
By default, the div will have expenseIcon background. ToggleClass will toggle the div class with colorToggle so will override the previous color.
You don't need an hyperlink tag A to manage clicks, just put it on the DIV.
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'});
}
}