I have 3 divs as colors to choose from and 3 blank divs. I want to let the user be able to:
(1) click a colored div and then a blank div, then the blank div is colored as the color the user choose. And the code seems to work.
(2) I want the user to be able to click the colored blank div again and it becomes white. And the code seems to work.
The problem is, if the blank div is colored and the user choose another color and click the colored blank div again, a newer color class will be added to the div, and things become unpredictable. You can open the console and track the messy change of the class of the blank div.
How can I solve this problem? I only want the blank divs to toggle between two classes.
var chosenColor;
function pickColor(arg){
chosenColor=arg.id;
}
function draw(id){
document.getElementById(id).classList.toggle("white");
document.getElementById(id).classList.toggle(chosenColor);
}
.box{
width: 100px;
height: 100px;
border: 1px solid black;
display: inline-block;
}
.red{background: red}
.blue{background: blue;}
.yellow{background: yellow;}
.white{background: white;}
<html>
<body>
<div class="box red" id="red" onclick="pickColor(this)">1</div>
<div class="box blue" id="blue" onclick="pickColor(this)">2</div>
<div class="box yellow" id="yellow" onclick="pickColor(this)">3</div>
<br><br>
<div class="box white" id="4" onclick="draw(4)">4</div>
<div class="box white" id="5" onclick="draw(5)">5</div>
<div class="box white" id="6" onclick="draw(6)">6</div>
</body>
</html>
Instead of using classes and running into the issue of assigning multiple nested classes or having to use complicated white logic...
I'd use data-* attribute:
var chosenColor;
function pick(el) {
chosenColor = el.dataset.color;
}
function draw(el) {
el.dataset.color = el.dataset.color ? "" : chosenColor;
}
body { background: #eee; }
.box {
width: 100px;
height: 100px;
border: 1px solid black;
display: inline-block;
background: white; /* BY DEFAULT !!! */
}
[data-color=red] { background: red; }
[data-color=blue] { background: blue; }
[data-color=yellow] { background: yellow; }
<div class="box" onclick="pick(this)" data-color="red">1</div>
<div class="box" onclick="pick(this)" data-color="blue">2</div>
<div class="box" onclick="pick(this)" data-color="yellow">3</div>
<br><br>
<div class="box" onclick="draw(this)">4</div>
<div class="box" onclick="draw(this)">5</div>
<div class="box" onclick="draw(this)">6</div>
What the ternary el.dataset.color = el.dataset.color ? "" : chosenColor; does is:
if the element has already any data-color set data-color to "" (nothing)
otherwise set data-color to the preselected chosenColor
Check to see if the element's classname is white. If not, set its class name to white - else, set it to the chosen color. You can put the boxes in a container and use .container > div selector, removing the need to give the boxes the .box class. Also, in a listener, this will refer to the clicked element - there's no need to use getElementById when you already have a reference to the element.
var chosenColor;
function pickColor(arg) {
chosenColor = arg.id;
}
function draw(element, id) {
if (element.className !== 'white') element.className = 'white';
else element.className = chosenColor;
}
.container > div {
width: 100px;
height: 100px;
border: 1px solid black;
display: inline-block;
}
.red {
background: red
}
.blue {
background: blue;
}
.yellow {
background: yellow;
}
.white {
background: white;
}
<div class="container">
<div class="red" id="red" onclick="pickColor(this)">1</div>
<div class="blue" id="blue" onclick="pickColor(this)">2</div>
<div class="yellow" id="yellow" onclick="pickColor(this)">3</div>
<br><br>
<div class="white" id="4" onclick="draw(this, 4)">4</div>
<div class="white" id="5" onclick="draw(this, 5)">5</div>
<div class="white" id="6" onclick="draw(this, 6)">6</div>
</div>
Answer
See - https://codepen.io/stephanieschellin/pen/xyYxrj/ (commented code)
or ...
var activeColor
function setPickerColor(event) {
activeColor = event.target.dataset.boxColorIs
}
function setThisBoxColor(event) {
let element = event.target
let the_existing_color_of_this_box = element.dataset.boxColorIs
if (the_existing_color_of_this_box == activeColor) {
delete element.dataset.boxColorIs
} else {
element.dataset.boxColorIs = activeColor
}
}
.box {
width: 100px;
height: 100px;
border: 1px solid black;
display: inline-block;
background: white;
}
[data-box-color-is="red"] {
background: red
}
[data-box-color-is="blue"] {
background: blue;
}
[data-box-color-is="yellow"] {
background: yellow;
}
<html>
<body>
<div id="box-1" class="box" data-box-color-is="red" onclick="setPickerColor(event)">1</div>
<div id="box-2" class="box" data-box-color-is="blue" onclick="setPickerColor(event)">2</div>
<div id="box-3" class="box" data-box-color-is="yellow" onclick="setPickerColor(event)">3</div>
<br>
<br>
<div id="box-4" class="box" onclick="setThisBoxColor(event)">4</div>
<div id="box-5" class="box" onclick="setThisBoxColor(event)">5</div>
<div id="box-6" class="box" onclick="setThisBoxColor(event)">6</div>
</body>
</html>
Using data- attributes you are able to decouple the JavaScript functional concerns form the CSS classes. This simplifies your logic but most importantly it allows folks styling your app to work independently from the folks adding JS functionality. This decoupling becomes really important when your team is using BEM or an OOCSS pattern.
Ideally instead of attaching styles to the data- attribute you would maintain the 'state' using data- and have another function that sets the classList based on the data- state. Allowing you to be 100% sure style changes you make will never effect JS functionality (QA will love you). But that's an evolution beyond this post.
With this setup we are not using the id's but I left them in because its an important best practice. Most likely this code would evolve into a component with listeners instead of inline onClick calls. JavaScript selectors should always be attached to id's or data- variables, never classes. Also, the id's should always be there for the QA team to utilize in their scripts. You risk some one changing a class name or removing it to adjust the styles and inadvertently breaking your JS listener.
I switched the arguments to pass the 'event' instead of the 'this' which is the element. Anyone using your JS event functions is going to expect the event object as the first parameter. You can pass 'this' as the second parameter if you like, but event.target will give you the same thing.
One other thing to note is the syntax change between declaring the data- variable and calling it from the JS.
HTML <div data-box-color-is="red">1</div>
JS event.target.dataset.boxColorIs
Regardless of how you format you data- attribute name it will always be parsed into camelCase when referencing it in JS ... data-box_color--IS would still become ... dataset.boxColorIs
Also as an evolution to your code you could remove the global JS var and store the value on the <body> or some other element on the page using data-. This will give you a single source of truth or 'state' that multiple features/components can reference without cluttering the global space.
Further Reading
https://css-tricks.com/bem-101/
https://en.bem.info/
https://philipwalton.com/articles/side-effects-in-css/
https://csswizardry.com/2015/03/more-transparent-ui-code-with-namespaces/
https://philipwalton.com/articles/decoupling-html-css-and-javascript/
Related
I have a game where there are balloons and each balloon has an onclick attribute which passes the id into a JS function to change the css.
Example:
<div id="balloon" class="container" onclick="popBalloon(this.id);"></div>
clicking this item will call the function below
function popBalloon(id){
document.getElementById(id).setAttribute("class","pop");
}
Problem is that I have multiples balloons of the same type, and instead of using a unique id for each one, I would like a way to determine the specific balloon being clicked using the same attribute names.
Is this possible?
If you pass event as the function parameter, you can use event.target to get the clicked Element
function popBalloon (event) {
event.target.setAttribute("class", "pop");
}
div {
margin-top: 10px;
height: 30px;
width: 30px;
border: 1px solid;
border-radius: 50%;
}
.container {
background-color: red;
}
.pop {
background-color: blue;
}
<div class="container" onclick="popBalloon(event);"></div>
<div class="container" onclick="popBalloon(event);"></div>
<div class="container" onclick="popBalloon(event);"></div>
<div class="container" onclick="popBalloon(event);"></div>
<div class="container" onclick="popBalloon(event);"></div>
Most of current answers suggest a function that defines click listener to a group of elements however you asked how to omit unique IDs where there are too many elements in a game. The simple answer is to pass OBJECT instead of ID to the function:
<div class="container" onclick="popBalloon(this);"></div>
and in the function:
function popBalloon(myobj){
myobj.setAttribute("class","pop");
}
Thats all.
Instead of manually entering the function signature in each balloon entry, handle it all in the javascript below. Throw all those balloons into a list. As Scott Hunter suggested, place each balloon in a class. Let's call it "balloon". Then add an event listener to each of those balloons. Here's a quick demo.
var balloonArray = document.querySelectorAll(".balloon");
balloonArray.forEach(function(item) {
item.addEventListener('click', function() {
item.innerText = "Clicked";
});
});
.container {
color: white;
height: 80px;
margin: 10px;
text-align: center;
}
<div class="container balloon" style="background-color: blue">Click me</div>
<div class="container balloon" style="background-color: red">Click me</div>
<div class="container balloon" style="background-color: green">Click me</div>
A good way to do it is add some class to all the balloons. Let's modify your code a bit
<div class="balloon"></div>
<div class="balloon"></div>
<div class="balloon"></div>
I have 3 of those divs with a class of balloon here. For the js we can do
Array.from(document.querySelectorAll(".balloon")).forEach(balloon=>{
balloon.addEventListener('click',()=>{
//On click event here
});
});
Here's how you add a click event to each of the balloon.
Basically i have this JSFiddle,
As you can see on the fiddle there is a long string of numbers ( they are an rgb code)
You can see that there also is just one box inside mydiv (totally forgot to add the others in for the palette).
Basically i need all the other RGB codes to have their own box to show the colors that the RGB represents.
Here is the code for you none JS Fiddlers
HTML
<span class="glyphicon glyphicon-ok"></span>
<h3>Make a Custom Theme from your image</h3>
<p> Based on your logo we believe this is the best colour scheme for you</p>
<div id="mydiv" style="background-color: rgb({{dominantColor}})"></div>
<h4>{{palette}}</h4>
<h4>
[[59,214,252],[217,236,252],[14,137,250],[4,31,156],[43,188,251],[13,86,199],[107,162,231],[53,117,204],[61,159,245]]
</h4> <!-- This is whats returned via the {{palette}} -->
<p>is this correct?</p>
<!--<button type="submit" class="btn btn-danger">Submit</button>-->
</div>
Css
#mydiv {
width: 100px;
height: 100px;
border: 1px solid #000;
}
I'm expecting to use JS to split up the codes, I can return the data without the square brackets [] So in theory i need the js to grab each rgb code and display the colour inside the box.
Half baked jsfiddle doesn't help much, really. Fiddle is for working example so we can see the existing condition and debug right away, not for you to paste your code for people to read.
Please refer to the snippet for solution. You can use ng-style to dynamically place the rgb values as css style.
angular.module('test', [])
.controller('Test', function($scope){
$scope.data = [[59,214,252],[217,236,252],[14,137,250],[4,31,156],[43,188,251],[13,86,199],[107,162,231],[53,117,204],[61,159,245]];
});
.box {
width: 50px;
height: 50px;
border: 1px solid #000;
float: left;
margin-right: 10px;
}
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.4.1/angular.min.js"></script>
<div ng-app='test' ng-controller='Test'>
<div class='box' ng-style="{'background-color': 'rgb('+color[0]+', '+color[1]+', '+color[2]+')'}" ng-repeat='color in data'></div>
</div>
I am trying to use JavaScript to change the background color of an element after being selected, and also to make sure that only one element at a time has the particular background color. Once the user selects on a different element I would like the previous element that was selected to be replaced by a different background color. Currently I am only able to toggle individual elements by selecting on EACH element. I need to be able to select on an element and apply the new background color, then have JavaScript change the background color of the previously active element to a different color (one less click).
What I am trying to do is very similar to modern navbars or list items where only one element at a time is “active” and has a background color that is different than the other elements in the same div, row, etc.
Notes about my work I am utilizing bootstrap and have no desire to use jQuery for this particular project.
CSS:
<!DOCTYPE html>
<html lang="en">
<head>
<style>
h4 {
border: 1px solid black;
border-radius: 8px;
padding: 10px 2px 10px 2px;
margin: 20px 20px 0px 20px;
background-color: #F0F0F0;
border-color: #F8F8F8;
color: #505050;
cursor: pointer;
}
.active {
background-color: #99E6FF;
}
</style>
</head>
</html>
HTML:
<div id="pTwoRowOne">
<div class="row">
<div class="col-md-4 row row-centered">
<h4 id="techBio" class="test">Biology</h4>
</div>
<div class="col-md-4 row row-centered">
<h4 id="techCart" class="test">Cartography</h4>
</div>
<div class="col-md-4 row row-centered">
<h4 id="techChem" class="test">Chemistry</h4>
</div>
</div>
</div>
JavaScript:
document.getElementById("techBio").onclick=function() {
document.getElementById("techBio").classList.toggle('active');
}
document.getElementById("techCart").onclick=function() {
document.getElementById("techCart").classList.toggle('active');
}
document.getElementById("techChem").onclick=function() {
document.getElementById("techChem").classList.toggle('active');
}
An example can be seen here: http://jsbin.com/fugogarove/1/edit?html,css,js,output
If clarification is needed let me know.
Yup, pretty straightforward.
Assumptions
You're not trying to support IE8, since you're using classList
You're okay with housing your elements as variables as opposed to repeatedly querying the DOM.
Example
JSBin
Code
I rewrote your JavaScript to make it a little bit cleaner and to DRY it up a bit:
var techs = [].slice.call(document.querySelectorAll('#pTwoRowOne h4'));
function set_active(event) {
techs.forEach(function(tech){
if (event.target == tech) { return; }
tech.classList.remove('active');
});
event.target.classList.toggle('active');
}
techs.forEach(function(item) {
item.addEventListener('click', set_active);
});
Some explanation
[].slice.call(document.querySelectorAll('#pTwoRowOne h4')); – We're using this to change the output from a NodeList to an Array. This allows us to use forEach later. querySelectorAll returns a NodeList that contains all elements matching the CSS selector. You can probably replace that with a better CSS selector depending on your environment.
addEventListener is a much nicer way than the iterative add via onclick += to bind an event listener. It's also the recommended way (as far as I know) in ECMA5 and later.
By setting the element queries as variables, you'll be able to keep the reference in memory instead of polling the DOM every time to alter elements. That'll make your JavaScript marginally faster, and it's again just a nicer, cleaner version of the code which it produces.
updates
I reworked the JS to make more sense.
Assuming you only ever have one active element, you can find it using document.querySelector() - if you can have multiples you can use document.querySelectorAll() and iterate through them.
Simple case:
function activate(event) {
var active=document.querySelector('.active');
// activate the clicked element (even if it was already active)
event.target.classList.add('active');
// deactivate the previously-active element (even if it was the clicked one => toggle)
if (active) active.classList.remove('active');
}
document.getElementById("techBio").addEventListener("click",activate);
document.getElementById("techCart").addEventListener("click",activate);
document.getElementById("techChem").addEventListener("click",activate);
h4 {
border: 1px solid black;
border-radius: 8px;
padding: 10px 2px 10px 2px;
margin: 20px 20px 0px 20px;
background-color: #F0F0F0;
border-color: #F8F8F8;
color: #505050;
cursor: pointer;
}
.active {
background-color: #99E6FF;
}
<div id="pTwoRowOne">
<div class="row">
<div class="col-md-4 row row-centered">
<h4 id="techBio" class="test">Biology</h4>
</div>
<div class="col-md-4 row row-centered">
<h4 id="techCart" class="test">Cartography</h4>
</div>
<div class="col-md-4 row row-centered">
<h4 id="techChem" class="test">Chemistry</h4>
</div>
</div>
</div>
Another similar yet simpler way to do it: jsBin ;)
var H4 = document.getElementsByClassName("test"), act;
[].forEach.call(H4, function(el){
el.addEventListener("click", function(){
if(act) act.classList.remove("active");
return (this.classList.toggle("active"), act=this);
});
});
You can do something like this:
[].slice.call(document.querySelectorAll(".test")).forEach(function(element) {
element.addEventListener('click', function(event) {
if (activeElement = document.querySelector(".test.active")) {
activeElement.classList.remove("active");
};
event.target.classList.add('active');
});
});
Basically, first we remove the active class from the active element, then we add it to the target.
JSBin
I have a table each one of them have a favorite option. I have used two star images to toggle between favorite and not favorite. ( I didnt use the checkbox because I want IE8 too).
I came up with the example below.
HTML
<div class="on" id="on_1" onclick="div_off(this.id);" style="display:none">off</div>
<div class="off" id="off_1" onclick="div_on(this.id);">on</div>
<div class="on" id="on_2" onclick="div_off(this.id);" style="display:none">off</div>
<div class="off" id="off_2" onclick="div_on(this.id);">on</div>
<div class="on" id="on_3" onclick="div_off(this.id);" style="display:none">off</div>
<div class="off" id="off_3" onclick="div_on(this.id);">on</div>
<div class="on" id="on_4" onclick="div_off(this.id);" style="display:none">off</div>
<div class="off" id="off_4" onclick="div_on(this.id);">on</div>
CSS
<style>
.on, .off {
cursor: pointer;
}
.on{
color: red;
}
.off{
color: blue;
}
</style>
JS:
<script>
function div_on(onId){
onId = onId.replace('off_','');
var on = document.getElementById('on_'+onId);
var off = document.getElementById('off_'+onId);
on.style.display = "block"
off.style.display = "none"
}
function div_off(offId){
offId = offId.replace('on_','');
var on = document.getElementById('on_'+offId);
var off = document.getElementById('off_'+offId);
on.style.display = "none"
off.style.display = "block"
}
</script>
Is there an other simple way of doing the same. I am trying to avoid any js classes / jquery.
example:
http://jsfiddle.net/yellowandred/LZkVb/1/
How about this? I've also included an example on how to get the clicked element's ID.
HTML:
<div class="off" id="toggle1" onclick="toggle(this);">off</div>
<div class="off" id="toggle2" onclick="toggle(this);">off</div>
<div class="off" id="toggle3" onclick="toggle(this);">off</div>
<div class="off" id="toggle4" onclick="toggle(this);">off</div>
JAVASCRIPT:
function toggle(el) {
var newState = (el.className === "off") ? "on" : "off";
el.className = newState;
el.innerHTML = newState;
alert("\"" + el.id + "\" is now " + newState + "!");
}
CSS:
.on, .off {
cursor: pointer;
}
.on {
color: red;
}
.off {
color: blue;
}
JSFiddle here.
Browser support for these JavaScript properties.
If you are looking to use star images for on/off states I would create an image sprite (an image containing the two images of the star) and use it as background image in a div. Then you use CSS classes to control the position of the background image. For example:
HTML:
<div id="star1" class="star"></div>
<div id="star2" class="star"></div>
CSS:
.star {
width: 20px;
height: 20px;
background-image: url("img/starsprite.png");
background-size: 20px 40px; /*We assume that the sprite contains a 20x20 px star in off state above a 20x20 px star in on state. Notice that the background is bigger than the div */
background-position: 0px 0px;
cursor: pointer;
}
.star.on {
background-position: 0px 20px;
}
JS:
$('body').on('click', '#star', function(event) {
var $this = $(this);
if($this.hasClass('on')) {
$this.removeClass('on');
}
else {
$this.addClass('on');
}
});
This way you halve the amount of DIVs needed. This is a quick example so you get the logic of the image sprite solution.
If you want to avoid jQuery it is possible with plain JavaScript as well, but I don't see the reason for not keeping things simple with jQuery.
There are a lot of tutorials on the web if you google for CSS image sprites.
This fiddle http://jsfiddle.net/dJBKw/1/ uses on/off text like your example.
HTML:
<div class="container" style="width:200px; height: 200px; border: 10px solid #ccc">
contents..
</div>
JQUERY:
$('.container').hover(function() {
console.log('in');
},
function() {
console.log('out');
});
It makes console.log when hover occurs both on border and div.
Objectives:
1> Want to make a `hover` event only for `div`, but not for `border`.
2> Fire another `hover` event on `border`, but not for `div`
Are the possible? if, then I want your cordial help..
A pragmatic solution would be to:
<div class="container" style="width:200px; height: 200px; border: 10px solid #ccc">
<div class="inner" style="height: 200px;">
contents..
</div>
</div>
and
$('.container .inner').hover(function() {
console.log('in');
},
function() {
console.log('out');
});
Cleanest option imo. a javascript solution would be more complex and simply not worth it.
The border IS the div, at least in part.
There's no event for specifically hovering over a border that I know of.
What you can do is have a nested div (within another div) and have a 10px padding on the internal one. This will give you 2 divs to work with and apply hover events to as well as looking the way you require.
Working example: http://jsfiddle.net/jssSA/
HTML
<div id="outer">
<div id="inner">Some content</div>
</div>
CSS
#outer,#inner{width:300px; height:300px;}
#outer{
background-color:#000;
padding:10px;
}
#inner{
background-color:#ccc;
}
jQuery
$('#outer').hover(function(){
console.log("outer in")},
function(){console.log("outer out")});
$('#inner').hover(function(){
console.log("inner in")},
function(){console.log("inner out")});