html javascript - javascript

I have a problem with javascript.
I need to add onclick listener for all img tags in my page, so click on an image should call imageClicked and pass element to function. but this code all time pass img src="../images/3.jpg" to function.
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<link rel="stylesheet" href="style.css" type="text/css" />
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Sample Page</title>
</head>
<body onload="start()">
<script type="text/javascript">
function start(){
var images = document.getElementsByTagName("img");
for ( var i = 0; i < images.length; i++) {
var image=images[i];
image.addEventListener('click', function(){
imageClicked(image);
});
}
}
function imageClicked(image){
alert(image.src)
}
</script>
<div id="main">
<div id="center">
<button>نمایش اسلایدی</button>
</div>
<div id="gallery">
<div id="img1" class="image">
<img src="../images/1.jpg"></img>
<div id="title">
<label>عکس</label>
</div>
</div>
<div id="img2" class="image">
<img src="../images/2.jpg"></img>
<div id="title">
<label>عکس</label>
</div>
</div>
<div id="img" class="image">
<img src="../images/3.jpg"></img>
<div id="title">
<label>عکس</label>
</div>
</div>
</div>
</div>

That is because of the scope. Everytime you loop the image value is set again. And so it will always pass the last image in the loop.
You can do 2 thing. Use the this like below. Or create an anonymouse function.
function start(){
var images = document.getElementsByTagName("img");
for ( var i = 0; i < images.length; i++) {
images[i].addEventListener('click', function(){
imageClicked(this);
});
}
}
// Or even better
function start(){
var images = document.getElementsByTagName("img");
for ( var i = 0; i < images.length; i++) {
images[i].addEventListener('click', imageClicked);
}
}
function imageClicked(){
alert(this.src); // this refers to the image
}
Anonymouse function:
function start(){
var images = document.getElementsByTagName("img");
for ( var i = 0; i < images.length; i++) {
(function(image){
image.addEventListener('click', function(){
imageClicked(image); // Use the element clicked object (this)
});
})(images[i]);
}
}

What you want is something like this:
function start(){
var images = document.getElementsByTagName("img");
for ( var i = 0; i < images.length; i++) {
images[i].addEventListener('click', function(){
imageClicked(this);
});
}
}
function imageClicked(image){
alert(image.src)
}
In the code you wrote, you copied the image element and then assigned an eventListener to the copy of the object. Because this copy was over-written multiple times, imageClicked was referred to by the only one that wasn't over-written, the last image. The this is to refer to the actual image element in the callback function.

Related

Slideshow javascript play/pause button

I'm making a slideshow in Javascript with a play/pause button. When I press one time on the button, the slideshow starts to play. When I press a second time, the slideshow has to stop. I only have no idea how to put this function in one button.
Here's my code:
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title>Oefening 19.7</title>
<link href="stijl_Oefening19_6.css" rel="stylesheet" />
<script>
var i = 0;
var foto = new Array(3);
var timer;
foto[0] = "images/slideshow/slideshow1.png";
foto[1] = "images/slideshow/slideshow2.png";
foto[2] = "images/slideshow/slideshow3.png";
foto[3] = "images/slideshow/slideshow4.png";
function slide() {
document.getElementById("slideshow").src = foto[i];
if (i < foto.length - 1) i++;
else i = 0;
timer = setTimeout("slide()", 3000);
}
</script>
</head>
<body>
<div id="portfolio">
<img src="images/slideshow/slideshow1.png" id="slideshow" alt="slideshow" />
</div>
<div id="button">
<a href="#" id="startcycle" onclick="slide()">
<img id="btnCycle" src="images/slideshow/cyclebutton.png" />
</a>
</div>
</body>
</html>
Use setInterval() instead. And separate the switch function and the slide function.
function slide() {
document.getElementById("slideshow").src = foto[i];
i = (i + 1)%foto.length;
}
function setTimer(){
if (timer) {
// stop
clearInterval( timer );
timer=null;
}
else {
timer = setInterval("slide()",1000);
}
}
Let the button call setTimer().

Auto Refresh Picture does not work in IE version 9

<!DOCTYPE html>
<html>
<head>
<meta http-equiv="X-UA-Compatible" content="IE=EmulateIE7">
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<link rel="stylesheet" type="text/css" href="test.css">
</head>
<body>
<img name="img" src="http://4.bp.blogspot.com/-Jdj5JKTA1xQ/T-BzvrQDZhI/AAAAAAAABhs/bX0TUEFb3Ck/s1600/windows-help1.png" width="90%" height="100%">
<script>
setInterval(function () {
var images = document.getElementsByTagName('img'); // get all img DOM objects
for (var i = 0; i < images.length; i++) {
images[i].src = images[i].src.replace(/\btime=[^&]*/, 'time=' + new Date().getTime());
}
}, 1000);
</script>
</body>
</html>
In Chrome I can see my picture refresh every second, but in IE version 9 it does not work. It does not refresh after displaying one time. How can I solve this problem, or is there any other way to do it?
The code, as is, should work. Also in IE 9.
Try something like this to verify that the scr attribute actually get changed:
Sample fiddle
JSFiddle does not work well in IE 8 – which I tested on, but this should give you a viewable sample for IE:
Sample fiddle
HTML:
<img src="http://jsfiddle.net/img/initializing.png?time=123" />
<img src="http://jsfiddle.net/img/initializing.png?time=123" />
<br/>
Img0.src: <input type="text" /><br/>
Img1.src: <input type="text" /><br />
Counter : <input type="text" />
CSS:
input {
width : 500px;
}
Javascript:
var img = document.getElementsByTagName('img');
var inp = document.getElementsByTagName('input');
var cnt = 0;
setInterval(function () {
inp[2].value = ++cnt;
for (var i = 0; i < img.length; i++) {
img[i].src = img[i].src
.replace(/\btime=[^&]*/, 'time=' + new Date().getTime());
inp[i].value = img[i].src;
}
}, 1000);

jquery preloaded imgages with rollovers

So I am doing something very basic that can be done with CSS but I want to do it with jQuery to get familiar with the library.
I am trying to create a rollover image gallery. Where when you put the mouse over the image it will be swapped with a slightly edited version of it.
Here is the code:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
<title>jQuery</title>
<script src="jquery-1.9.1.js"></script>
<style>
</style>
</head>
<body>
<div id="gallery">
<img src="images/one_s.jpg" />
<img src="images/two_s.jpg" />
<img src="images/three_s.jpg" />
<img src="images/four_s.jpg" />
<img src="images/five_s.jpg" />
<img src="images/six_s.jpg" />
</div>
<script>
$(document).ready(function(){
var alternate = ['images/one_s_edited.jpg',
'images/two_s_edited.jpg',
'images/three_s_edited.jpg',
'images/four_s_edited.jpg',
'images/five_s_edited.jpg',
'images/six_s_edited.jpg'];
var $selection = $("#gallery img");
for(var i = 0; i < alternate.length; i++)
{
var imgObject = new Image();
var downloadedImg = imgObject.src = alternate[i];
console.log(downloadedImg);
var originalSrc = $selection.eq(i).attr("src");
console.log(originalSrc + "\n");
$selection.eq(i).hover(
function(){
$(this).attr("src", downloadedImg);
},
function(){
$(this).attr("src", originalSrc);
}
);//End hover
}//End loop
});//End ready
</script>
</body>
</html>
Here is a link to the final result: link
As you can see it rolls over but not as planned. It ends up with the last rollover-image and doesn't change back to the original nor does it show the appropriate rollover image that corresponds with it.
Any simple suggestions without using regular expressions?
The problem is the wrong usage of a closure variable in a loop.
But the solution can be simplified to
$(document).ready(function () {
var $selection = $("#gallery img");
$selection.hover(function () {
this.src = this.src.replace('.jpg', '_edited.jpg')
}, function () {
this.src = this.src.replace('_edited.jpg', '.jpg')
})
}); //End ready

Javascript for slideshow [closed]

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Want to improve this question? Update the question so it focuses on one problem only by editing this post.
Closed 8 years ago.
Improve this question
Can someone suggest good javascript code to implement slideshow such that all the elements of slideshow are declared in or an array.I want it using purely javascript without using jQuery
This may be useful to you. Copy and replace images.
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>image slide show</title>
<style type="text/css">
body {
background:#FFC;
}
input[type="button"] {
background:#939907;
color:#fff;
border:1px solid #434603;
-moz-border-radius:5px;
-webkit-border-radius:5px;
-ms-border-radius:5px;
font-weight:bold;
cursor:pointer;
height:25px;
}
img {
width:525px;
height:200px;
border:2px solid #CF3;
-moz-border-radius:15px;
-webkit-border-radius:15px;
-ms-border-radius:15px;
}
</style>
<script type="text/javascript">
var images=new Array();
var i=0, t, f=false;
images[0] ="images/heli1.jpg";
images[1] ="images/heli2.JPG";
images[2] ="images/heli3.JPG";
images[3] ="images/heli4.JPG";
images[4] ="images/heli5.JPG";
images[5] ="images/heli6.JPG";
images[6] ="images/heli7.JPG";
images[7] ="images/heli2.JPG";
images[8] ="images/heli9.JPG";
images[9] ="images/heli1.jpg";
images[10] ="images/heli2.JPG";
images[11] ="images/heli3.JPG";
images[12] ="images/heli4.JPG";
images[13] ="images/heli5.JPG";
images[14] ="images/heli6.JPG";
function start(){
if(i>=images.length){
i=0;
document.getElementById('img').src=images[i];
i++;
}
else{
document.getElementById('img').src=images[i];
i++;
}
t=setTimeout("start()", 1000);
}
function play(){
if(f==false){
f=true;
start();
}
}
function Stop(){
clearTimeout(t);
f=false;
}
function next(){
if(i>=images.length){
i=0;
document.getElementById('img').src=images[i];
i++;
}
else{
document.getElementById('img').src=images[i];
i++;
}
}
function previous(){
if(i>=images.lenght){
i=images.length;
document.getElementById('img').src=images[i];
i--;
}
else if(i<=0){
i=images.length;
document.getElementById('img').src=images[i-1];
i--;
}
else if(i>images.length){
document.getElementById('img').src=images[images.length-i];
}
else if(i<=images.length || i>0){
document.getElementById('img').src=images[i-1];
i--;
}
}
</script>
</head>
<body>
<table width="50%" border="0" cellspacing="0" cellpadding="0" align="center">
<tr>
<td><input type="button" value="Previous" onclick="previous()" /></td>
<td align="center"><img src="images/heli6.JPG" alt="" id="img" /></td>
<td><input type="button" value="Next" onclick="next()" /></td>
</tr>
<tr>
<td colspan="3" align="center" height="50"><input type="button" value="Play" onclick="play()" />
<input type="button" value="Stop" onclick="Stop()" /></td>
</tr>
</table>
</body>
</html>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Untitled Document</title>
</head>
<body>
<script language="javascript">
loaded_img = 0;
no_of_img = 12;
img_name = new Array();
img_name.length = no_of_img - 1;
for ( var count = 0; count < no_of_img; count++)
{
var file_num = count + 1;
var filename = ("img" + file_num + ".jpg");
img_name[count] = filename;
}
var whichlink=0
function slideit(){
if (!document.images)
return
document.images.myimage.src=img_name[loaded_img].src
whichlink=loaded_img
if (loaded_img<img_name.length-1)
loaded_img++
else
loaded_img=0
setTimeout("slideit()",1000)
}
slideit()
function changeImage(direction)
{
loaded_img=loaded_img+direction;
if (loaded_img < 0)
loaded_img = no_of_img - 1;
if (loaded_img == no_of_img)
loaded_img = 0;
document.myimage.src = img_name[loaded_img];
}
</script>
<script language="javascript">
//slideshowimages()=new Array()
//slideshowimages("img1.jpg")
var whichlink=0
var whichimage=0
function slideit(){
if (!document.images)
return
document.images.myimage.src=slideimages[whichimage].src
whichlink=whichimage
if (whichimage<slideimages.length-1)
whichimage++
else
whichimage=0
setTimeout("slideit()",1000)
}
slideit()
</script>
<form>
<img src="left-disabled.gif" width="27" height="22" border="0">
<img src="img1.jpg" name="myimage">
<img src="right-enabled.gif" width="27" height="22" border="0">
</form>
</body>
</html>
This question is old, but here is a more comprehensive example with pure JavaScript. It assumes that index.html and slideshow.js are on the same level. It begins with an automatically playing slideshow (that can be paused and resumed), and it also has previous and next buttons. If you only want one of those sets of functionality, it should be fairly straightforward to remove the other.
The HTML is very barebones and can be altered as desired for the most part as long as you mind the ids. I haven't provided any styling, so that's all you.
<!-- index.html -->
<!DOCTYPE html>
<html>
<head lang="en">
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>slideshow</title>
</head>
<body>
<section>
<div>
<img id="image">
</div>
<div>
<button type="button" id="playBtn">Play</button>
<button type="button" id="pauseBtn">Pause</button>
</div>
<div>
<button type="button" id="prevBtn">Prev</button>
<button type="button" id="nextBtn">Next</button>
</div>
</section>
<script src="slideshow.js"></script>
</body>
</html>
If you want to support IE8 and/or below, you'll need to ditch the DOMContentLoaded listener. Essentially, you could just extract the IIFE and then replace its final line return beginSlideshow with beginSlideshow(). I hope that makes sense, and I hope you find this helpful. Good luck.
// slideshow.js
document.addEventListener(
// IE 9 and up. See http://caniuse.com/#feat=domcontentloaded
'DOMContentLoaded'
, (function STRICT() {
'use strict';
// Avoid 'new' and stick to array literals where possible.
var images =
[ 'img/30.gif'
, 'img/31.gif'
, 'img/32.gif'
, 'img/33.gif'
, 'img/34.gif'
]
, img = document.getElementById('image')
, playBtn = document.getElementById('playBtn')
, pauseBtn = document.getElementById('pauseBtn')
, prevBtn = document.getElementById('prevBtn')
, nextBtn = document.getElementById('nextBtn')
, index = 0
, indexOfLastImage = images.length - 1
, play
, playInterval
, pause
, goToPrevious
, goToNext
, beginSlideShow
play = function() {
playInterval = setInterval(
function() {
if (index === indexOfLastImage) { index = 0 }
img.src = images[++index]
}
, 3000
)
}
pause = function() {
clearInterval(playInterval)
playInterval = null
}
goToPrevious = function() {
// if the slideshow was running
if (playInterval) { pause() }
// if we're at the beginning of the array
if (index === 0) {
index = indexOfLastImage + 1
}
img.src = images[--index]
}
goToNext = function() {
// if the slideshow was running
if (playInterval) { pause() }
// if we're at the beginning of the array
if (index === indexOfLastImage) {
index = -1
}
img.src = images[++index]
}
beginSlideShow = function() {
// add listeners
playBtn.addEventListener('click', play)
pauseBtn.addEventListener('click', pause)
prevBtn.addEventListener('click', goToPrevious)
nextBtn.addEventListener('click', goToNext)
// set initial image for display prior to first interval
img.src = images[index]
// kick off auto play
play()
}
// This is what's attached to and will fire on the DOMContentLoaded event
return beginSlideShow
}())
)

change to next image automatically

I have the following code used for displaying several images changed on hover, but i also would like to add a feature that changes the image automatically if i dont do it manually.
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Untitled Document</title><br />
</head>
<body>
<p>
<script type="text/javascript" language="javascript">
function changeImage(img){
document.getElementById('bigImage').src=img;
}
</script>
<img src="../Pictures/lightcircle.png" alt="" width="284" height="156" id="bigImage"
/>
<p> </p>
<div>
<p>
<img src="../Pictures/lightcircle2.png" height="79" width="78"
onmouseover="changeImage('../Pictures/lightcircle2.png')"/>
</p>
<p><img src="../Pictures/lightcircle.png" alt="" width="120" height="100"
onmouseover="changeImage('../Pictures/lightcircle.png')"/></p>
<p><img src="../Pictures/lightcircle2.png" alt="" width="78" height="79"
onmouseover="changeImage('../Pictures/lightcircle2.png')"/></p>
<p> </p>
</br>
</div>
</body>
</html>
What i want to do is automatically change the images displayed using javascript preferrably. How can i do that?
Use setInterval to run a function that changes the image src.
var x = 0;
var images = new Array("../Pictures/lightcircle2.png","../Pictures/lightcircle.png");
var i = setInterval(auto, 3000);
function auto()
{
x++;
if (x == images.length)
x=0;
document.getElementById('bigImage').src=images[x];
}
This should help you:
http://www.switchonthecode.com/tutorials/javascript-tutorial-using-setinterval-and-settimeout
Sounds like you want a carousel. If so, try this.
Add this to your JavaScript
// The list of images you want to cycle through
var imageRotation = [
'../Pictures/lightcircle.png',
'../Pictures/lightcircle2.png'
];
// The current image being displayed
var currentImage = 0;
// A variable to hold the timer
var t;
// Call this to automatically start rotation. Currently set for a 5 sec rotation
function startCarousel(){
t=setInterval(changeCarousel,5000);
}
// Moves to the next picture
function changeCarousel(){
// Change to the next image
currentImage++;
// If there isn't a next image, go back to the start
if (currentImage == imageRotation.length) currentImage = 0;
// Change the image
document.getElementById('bigImage').src=imageRotation[currentImage];
}
Then modify your function to
function changeImage(img){
// Stops the rotation
clearInterval(t);
// Assigns currentImage to the image they selected
currentImage = imageRotation.indexOf(img);
// Swap the image
document.getElementById('bigImage').src=imageRotation[currentImage];
// Start the rotation again in 10 sec
setTimeout(startCarousel, 10000);
}

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