Showing random divs images every time page is load - javascript

Lets say I have these images gallery, how do i randomly display the images everytime when i reload the page?
http://creativepreviews.com/fiddle/study/20131007/

Let's say the image will display in the background of the DIV, then the following should do it.
// JS
var imgArray = ["img1.jpg", "cat.jpg", "sky.jpg"]
function randomBg() {
x = Math.random()
y = Math.round(x * 10)
if (imgArray[y] != undefined) {
document.getElementById("blah").style.backgroundImage = "url('" + imgArray[y] + "')"
} else {
document.getElementById("blah").style.backgroundImage = "url('default.jpg')"
}
}
...and the HTML.
<script src="test.js"></script>
<body onload="randomBg()">
<div id="blah"></div>
...or you could replace the style.backgroundImage in the JS with innerHTML = <img src=" etc...

You could do something along these lines (not tested)
var grd = $('#grid');
var imgs = grd.children();
imgs.sort(function(){return (Math.round(Math.random()) - 0.5);});
grd.remove('li');
for(var i=0;i < imgs.length;i++) grd.append(imgs[i]);
In essence what we are doing is getting all the li elements in 'grid' into an array, randomizing them, removing them all from 'grid' and then putting them back in again.
If you had supplied a working fiddle rather than a link to the finished article it would be easier to modify it and provide a more complete solution.

Related

Generate array of image in javascript inside <div>

I need to make the background image in div tag and it has to change automatically, I already put the array of images inside the javascript, but the images is not showing when i'm run the site.The background should behind the menu header.
This is the div
<div style="min-height:1000px;position:relative;" id="home">
below of the div is containing the logo, menu and nav part.
<div class="container">
<div class="fixed-header">
<!--logo-->
<div class="logo" >
<a href="index.html">
<img src="images/logo.png" alt="logo mazmida" height="142" width="242">
</a>
</div>
<!--//logo-->
This is the javascript
<script>
var imgArray = [
'images/1.jpg',
'images/2.jpg',
'images/3.jpg'],
curIndex = 0;
imgDuration = 2000;
function slideShow() {
document.getElementID('home').src = imgArray[curIndex];
curIndex++;
if (curIndex == imgArray.length) { curIndex = 0; }
setTimeout("slideShow()", imgDuration);
}
slideShow();
You have a few issues with your script. I've made a live JSbin example here:
https://jsbin.com/welifusomi/edit?html,output
<script>
var imgArray = [
'https://upload.wikimedia.org/wikipedia/en/thumb/0/02/Homer_Simpson_2006.png/220px-Homer_Simpson_2006.png',
'https://upload.wikimedia.org/wikipedia/en/thumb/0/0b/Marge_Simpson.png/220px-Marge_Simpson.png',
'https://upload.wikimedia.org/wikipedia/en/a/aa/Bart_Simpson_200px.png'
];
var curIndex = 0;
var imgDuration = 1000;
var el = document.getElementById('home');
function slideShow() {
el.style.backgroundImage = 'url(' + imgArray[curIndex % 3] + ')';
curIndex++;
setTimeout("slideShow()", imgDuration);
}
slideShow();
</script>
There are a few issues with your script:
On the element since it's a div not an img, you need to set style.backgroundImage instead of src. Look at https://developer.mozilla.org/en-US/docs/Web/CSS/background for other attributes to related to background image CSS
Also it's document.getElementById
Optimizations
And you can use mod % trick to avoid zero reset
Use setInterval instead of setTimeout
Further optimzations
Use requestAnimationFrame instead of setTimeout/setInterval
I suggest getting familiar with your browser debugging tools which would help identify many of the issues you face.
document.getElementID('home').src = imgArray[curIndex]
You are targeting a div with an ID of home, but this is not an Image element (ie ,
But since you want to alter the background colour of the DIV, then you use querySelector using javascript and store it in a variable, then you can target the background property of this div (ie Background colour).
I hope this helps.
You are trying to change the src property of a div, but divs do not have such property.
Try this:
document.getElementById('home').style.backgroundImage = "url('" + imgArray[curIndex] + "')"
This changes the style of the target div, more precisely the image to be used as background.
As you want to change the background image of the div, instead of document.getElementID('home').src = imgArray[curIndex] use
document.getElementById("#home").style.backgroundImage = "url('imageArray[curIndex]')";
in JavaScript or
$('#home').css('background-image', 'url("' + imageArray[curIndex] + '")'); in jquery.
To achieve expected result, use below option of using setInterval
Please correct below syntax errors
document.getElementID to document.getElementById
.src attribute is not available on div tags
Create img element and add src to it
Finally use setInterval instead of setTimeout outside slideShow function
var imgArray = [
'http://www.w3schools.com/w3css/img_avatar3.png',
'https://tse2.mm.bing.net/th?id=OIP.ySEgAgJIlDQsIQTu_MeoLwHaHa&pid=15.1&P=0&w=300&h=300',
'https://tse4.mm.bing.net/th?id=OIP.wBAPnR04OfXaHuFI9Ny2bgHaE8&pid=15.1&P=0&w=243&h=163'],
curIndex = 0;
imgDuration = 2000;
var home = document.getElementById('home')
var image = document.createElement('img')
function slideShow() {
if(curIndex != imgArray.length-1) {
image.src = imgArray[curIndex];
home.appendChild(image)
curIndex++;
}else{
curIndex = 0;
}
}
setInterval(slideShow,2000)
<div style="position:relative;" id="home"></div>
code sample - https://codepen.io/nagasai/pen/JLKvME

Show / Hide images randomly using jQuery

I want to create a function that grabs all the instances of an image class on the page. As default these will be hidden, then randomly after a certain interval show one of those images (can be any image). Then the function will rerun and show another image. (whilst hiding the image that was shown on the first run through.
I've got to this stage with the function (not currently working)
(function randomShow() {
var showDiv = $('.show'),
el = showDiv.eq(Math.floor(Math.random() * showDiv.length));
el.show().delay(2000).show(randomShow);
})();
Thanks
I put together a jsFiddle using divs in place of images to demonstrate (pure js):
http://jsfiddle.net/oogley_boogley/az9gd8wf/
the script:
var divs = document.getElementsByClassName('square');
var arrLength = divs.length;
var randomNumberLimit;
var interval_speed = 1000;
setInterval(function(){
randomNumberLimit = Math.floor((Math.random() * arrLength) + 1);
for(i=0;i<arrLength;i++){
var matchingDiv = divs[i];
if(matchingDiv.id == randomNumberLimit){
matchingDiv.setAttribute("class","showing square blue");
}
if(matchingDiv.id != randomNumberLimit){
matchingDiv.setAttribute("class","hiding square blue");
}
}
}, interval_speed);

get name of files in a folder with javascript

I have a background image folder that there is some picture that i want to use them for background.
how i can get their names and put them on array whit javascript?if i cant they do with javascript,how can i do that?
i want to read name of files and use javacsript and link for change background image whit css.
<script>
function nextbg(){
$('#bg').css('background-image','url(Images/bg2.jpg)');
}
</script>
This solution is created according to the fact that browser dont have access to folders/filesystem.
Javascript can not access the filesystem. This has to be done by a server script and then be feed to the javascript.
I had the simliar problem when building my game engine when I was loading all my diffrent tiles. I ended up doing it like this.
This solution do pose two a problems when implementing it.
You will have to define the amout of images in the "NrofTiles" array
The images must be named like tile1, tile2 ... tile9 so you can
increment the path to them.
The typeOfTiles[typeCounter] is just there to give me access to different folders, in my case for my tiles, grass, houses, water and so on.
for(var i = 0; i <= nrofTiles.length; i++)
{
for(var x = 0; x <= nrofTiles[i]; x++)
{
console.log
("Fetching tile "+(x + 1 )+" of " + 14);
img = new Image();
//My path
img.src = 'Images/Cart/' + typeOfTiles[typeCounter] + '/' + (x + 1) + '.png';
imgArray.push(img);
var intervalFunctionen = function () {
alert("calls back here");
};
}//end for loop!
}end outer for loop!
When everything is loaded(the tiles), you do this to change the background picture.
This is an example of a changing body background. You could make a link with an ID lets say "iamthelink".
HTML
Change BG
JAVASCRIPT
var link = document.getElementsById('iamthelink');
link.onclick= function() {
var body = document.getElementsByTagName('body')[0];
body.style.backgroundImage = 'url(http://localhost/background.png)';
}

I can change background images, but how to print link?

I am using JavaScript to randomly change the background image upon refresh. What I have been wanting to do is then take the current background-image url and paste it in a certain div within
so that people can download the image.
The background image script works and is as follows:
var totalCount = 3;
function ChangeIt()
{
var num = Math.ceil( Math.random() * totalCount );
document.body.background = 'bgimages/'+num+'.jpg';
document.body.style.backgroundRepeat = "repeat";// Background repeat
}
Sorry if this is easy but I haven't been able to figure out how to do it! Can anyone point me in the right direction?
Let's assume you have this link somewhere in your document and you want it to point to the current background image:
<a href='#' id='bgDownload'>Download background image</a>
The following function changes now the "href"-attribute of the link to the current background and the background itself:
var totalCount = 3;
function ChangeIt()
{
var num = Math.ceil( Math.random() * totalCount );
document.body.background = 'bgimages/'+num+'.jpg';
document.body.style.backgroundRepeat = "repeat";// Background repeat
// change link
document.getElementById("bgDownload").href = 'bgimages/'+num+'.jpg';
}
I hope it helps...
Put a DIV on your page in the HTML, and switch the content using...
document.getElementById("[ID of DIV]").innerHTML = '' + [text_var] + '';
Something like this...
document.getElementById("[ID of DIV]").innerHTML = 'Image #' + num + '';
Try this
<a href='javascript:window.location.href=document.body.background'>
Download Background
</a>
try this :  
  
function downloadImage{
window.open(document.body.background,'_blank');
}

Getting images to change in a for loop in javascript

So far I created an array with 11 images, initialized the counter, created a function, created a for loop but here is where I get lost. I looked at examples and tutorial on the internet and I can see the code is seeming simple but I'm not getting something basic here. I don't actually understand how to call the index for the images. Any suggestions. Here is the code.
<script type="text/javascript">
var hammer=new Array("jackhammer0.gif",
"jackhammer1.gif",
"jackhammer2.gif",
"jackhammer3.gif",
"jackhammer4.gif",
"jackhammer5.gif",
"jackhammer6.gif",
"jackhammer7.gif",
"jackhammer8.gif",
"jackhammer9.gif",
"jackhammer10.gif")
var curHammer=0;
var numImg = 11;
function getHammer() {
for (i = 0; i < hammer.length; i++)
{
if (curHammer < hammer.length - 1) {
curHammer = curHammer +1;
hammer[i] = new Image();
hammer[i].src="poses/jackhammer" +(i+1) + ".gif";
var nextHammer = curHammer + 1;
nextHammer=0;
{
}
}
}
}
setTimeout("getHammer()", 5000);
</script>
</head>
<body onload = "getHammer()";>
<img id="jack" name="jack" src = "poses/jackhammer0.gif" width= "100" height ="113" alt = "Man and Jackhammer" /><br/>
<button id="jack" name="jack" onclick="getHammer()">Press button</button>
Following on what Paul, said, here's an example of what should work:
var hammer=["jackhammer0.gif","jackhammer1.gif","jackhammer2.gif","jackhammer3.gif",
"jackhammer4.gif","jackhammer5.gif","jackhammer6.gif","jackhammer7.gif",
"jackhammer8.gif","jackhammer9.gif","jackhammer10.gif"];
var curHammer=0;
function getHammer() {
if (curHammer < hammer.length) {
document.getElementById("jack").src= "poses/" + hammer[curHammer];
curHammer = curHammer + 1;
}
}
setTimeout("getHammer()", 5000);
The big missing element is that you need to call getElementById("jack") to get a reference to the DOM Image so that you can change it's source. If you're using jQuery or most other JS frameworks, just type $("#jack") to accomplish the same.
I don't understand the need for the for loop at all, just increment the index value [curHammer] each time you click, and reset if it passes your max index length (in this case 11).
Pseudo-Code:
currentHammer = -1
hammers = [ "a1.jpg", "a2.jpg", "a3.jpg"]
getHammer()
{
currentHammer = currentHammer + 1;
if(currentHammer > 2)
currentHammer = 0;
image.src = hammers[currentHammer];
}
a) are you just trying to show an animated gif? If so, why not use Adobe's Fireworks and merge all those gifs into a single gif?
b) you know that the way you have it the display is going to go crazy overwriting the gif in a circle right?
c) you might want to put a delay (or not). If so, make the load new gif a separate function and set a timeout to it (or an interval).
Also, you are being redundant. How about just changing the src for the image being displayed?:
var jackHammer = new Array();
for (var i=0;i<11;i++) { //pre-loading the images
jackHammer[i] = new image();
jackHammer[i].src = '/poses/jackHammer'+i.toString()+'.gif';
} //remember that "poses" without the "/" will only work if that folder is under the current called page.
for (var i=0;i<11;i++) { //updating the image on
document.getElementById('jhPoses').src = jackHammer[i].src;
}
on the document itself,
< img id='jhPoses' src='1-pixel-transparent.gif' width='x' height='y' alt='poses' border='0' />

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