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JavaScript "<SCRIPT>" in Image src attribute

So I have the following JavaScript function.
var LogoUrl = function() {
document.write('views/img/common/site-logo.svg');
}
And I want to have this function used in a html img src attribute.
Here is a example though this syntax wouldn't work, it should give you an idea of what I am looking for.
<img class="site-logo" src="<script> LogoUrl() </script>" alt="Site Logo">
And hoping this would export the following in the browser
<img class="site-logo" src="views/img/common/site-logo.svg" alt="Site Logo">
What is the best approach to doing this?

You can do this with the following instead:
<script>
document.write('<img class="site-logo" src="' + 'views/img/common/site-logo.svg' + '" alt="Site Logo">');
</script>
Since the script tag is indeed a tag, you can't put it inside the attributes of another tag.
A much better approach however would be the following:
Prepare a span element for the element to appear in, and give it a specific id. This would be your HTML:
This is my image: <span id="myImg"></span>.
and this will be your jQuery code:
$(function() {
$('<img>').class('site-logo')
.attr('src', 'views/img/common/site-logo.svg')
.attr('alt', 'Site Logo')
.appendTo('#myImg');
});
Alternatively, instead of preparing a span, you could prepare the image without defining a src attribute, with the following HTML:
This is my image: <img id="myImg" class="site-logo" alt="Site Logo">.
and the following jQuery code:
$(function() {
$('#myImg').attr('src', 'views/img/common/site-logo.svg');
});

You can use jquery $(document).ready() to set the image src.
$(document).ready(function (){
$('img.site-logo').attr('src', 'views/img/common/site-logo.svg');
});

You could do this - but this makes it obstructive.
<script>document.write("<img class=\"site-logo\" src=\"views/img/common/site-logo.svg\" alt=\"Site Logo\">")</script>
It is also not very organised because it ties everything so much with the markup that you might as well just have it as markup.
You're better off doing it properly by changing the src property
var logo = document.getElementsByClassName('site-logo')[0];
logo.src = 'http://www.develop.com/Images/v3/tech-symbols/angularjs_logo.png';
demo here http://jsfiddle.net/andyw_/XxTuA/268/
If this is all you need to do - I don't think it justifies the use of a selector library or front-end framework.

Swap images with single button JavaScript function using %

Fellow Programmers! A wonderful afternoon (or whatever the case) to you!
With some assistance of fellow users I was able to manage getting an image to change back and forth between a second image every couple seconds. It's awesome! So I counted out some of the math with the % operator, and sure enough when the image first displays, I get the default broken link image of the browser, but after the 2 seconds everything goes as planned.
So begins this investigative experiment.
I decided instead of swapping automatically, lets make the swap with a button as to be able to investigate the page as long as I would like. But who want's to do the exact same thing again, why not learn another cool trick along the way. That trick is to display both of the images at the same time, such that when the button is clicked they swap places. Same math, different effect for the user. Isn't that awesome!
The goal:
display two images and below them one button. When the button is clicked the images are to swap places. The images that was on the left should be on the right, the one on the right ought now be on the left. Use no jQuery, this is after all a JavaScript experiment (and I have yet to learn much jQuery but I can't wait to get there!)
Browser error console messages:
Interestingly enough firefox give me nothing. I open the browser, load the page in it from VS 2012 clear the error conslole, refresh the page. And nothing.
In chrome (my default browser) however, I get a localhost pic src 404 not found.
I find this strange because this code is on a page that happens to have other code which references those same pictures and works fine. The 2 second auto img flip thing being some of that other code.
debugging:I'm to much of a noob to know what's going on with that. I get the basic Idea and looked into it some. On the VS site there's all this info about setting breaking points and running multiple instance of VS to do something with another engine. I will soon be on youtube to hammer that out. I apologize however, if there is some simple debug fix to this and I should have witnessed it. Hammering through my 2nd web class and that topic has not been covered :(
Here are articles that I found similar to my question.
This was helpful to see how they had set up the if else:
https://stackoverflow.com/questions/15671442/swap-image-with-onclick-not-responding
all in all that turned out to be more that I could read, clearly the writer is more advanced than I.
a second: javascript swap text block onclick anchor link a bit of an information overload I think. There was a lot going on with that, but I never managed to change any of my code after reading through it.
If your curious here is the VS article I briefly mentioned:
http://blogs.msdn.com/b/visualstudioalm/archive/2013/06/28/javascript-native-interop-debugging-in-visual-studio-2013.aspx
And here is my code:
<script type="text/javascript">
function swap_pics() {
var c = 1
//I had:
//var andy_arr = ["andy_white.jpg","andy_black.jpg"];
var andy_src1 = "andy_left.jpg";
var andy_src2 = "andy_right.jpg";
c = ((c + 1) % 2);
if (c == 0) {
//I was using an array which looked like:
// document.getElementById('andy_left').src = "andy_arr[0]";
// document.get ... _right').src = andy_arr[Math.abs(c-1)];
//0-1 abs = 1
//1-1 = 0, so It looks like it should now toggle.
document.getElementById('andy_left').src = andy_src1;
document.getElementById('andy_right').src = andy_src2;
}
else {
document.getElementById('andy_left').src = andy_src2;
document.getElementById('andy_right').src = andy_src1;
}
}
</script>
<div id="mini_lab_5">
<img src=""
id="andy_left"
height="100"
width="100"
/>
<img src=""
id="andy_right"
height="100"
width="100"
/>
<br />
<input type="button" value="Swap"
onclick="swap_pics();
"/>
</div>
Thanks for being a part of the community and making it great!

You could add the images directly to your img tags like this :
<img src="andy_left.jpg"
id="andy_left"
height="100"
width="100"
/>
<img src="andy_right.jpg"
id="andy_right"
height="100"
width="100"
/>
Then your images should appear by default in your page, if not your links to the images are not good.
Then you could replace your current swap_pics function with the following :
function swap_pics() {
var andy_left = document.getElementById('andy_left'),
andy_right = document.getElementById('andy_right'),
andy_left_src = andy_left.src,
andy_right_src = andy_right.src;
andy_left.src = andy_right_src;
andy_right.src = andy_left_src;
}
Here is a simple jsfiddle doing this: http://jsfiddle.net/X9YTP/

Here you go good luck.
<html>
<head>
<script type="text/javascript">
function switchImage () {
var imgleft = document.getElementById('image1'),
imgright = document.getElementById('image2'),
img_left_src = imgleft.src,
img_right_src = imgright.src;
imgleft.src = img_right_src;
imgright.src = img_left_src;
}
</script>
</head>
<body>
<div>
<img id="image1" src="./home-cat.jpg" />
<button id="butnum" onclick="switchImage();">Switch</button>
<img id="image2" src="./images.jpeg" />
</div>
</body>
</html>

JavaScript HTML: Image with hover function disappears

I am experiencing some problems with my javaScript hover function on two images. When the user hovers over the arrow image it should change into a hover-version of that image, and if the user clicks on it it should start another javascript function to expand/collapse the below tabs. Here is the live site. The problem is with the arrows on the right side below the navigation.
At first I tried doing this with only HTML code (onMouseOver and onMouseOut, and just load different image), but got a nasty bug where if the user hovered over the first arrow, then the second, and back to the first, then the second would completely disappear.
Now I tried with JavaScript instead, but now you can only see the first arrow, and that disappears if you hover to the right of it.
The annoying part is that it works perfectly fine from the local server, but not on the web server. I've not used much HTML/Javascript before, and never used JQuery. If this can be solved easily with something like that, I would be really grateful for some help on how to do so. I've read some solutions with CSS background, but don't think that would work because the image must work as a button as well?
Here is the JS code for changing the images
var images= new Array();
images[0] = "img/ArrowDown.png";
images[1] = "img/ArrowDownHover.png";
images[2] = "img/ArrowUp.png";
images[3] = "img/ArrowUpHover.png";
function DownChange()
{
document.getElementById("expandAll").src = images[1];
}
function DownGoBack()
{
document.getElementById("expandAll").src = images[0];
}
function UpChange()
{
document.getElementById("collapseAll").src = images[3];
}
function UpGoBack()
{
document.getElementById("collapseAll").src = images[2];
}
Here is the HTML code
<div id="collapse">
<img src="img/arrowDown.png" id="expandAll" onMouseOver="DownChange()" onMouseOut="DownGoBack()" onClick="openAll()"></img>
<img src="img/arrowUp.png" id="collapseAll" onMouseOver="UpChange()" onMouseOut="UpGoBack()" onClick="closeAll()"></img>
</div>

If it is working on your local machine, the problem isn't coming from your JS.
The problem I would guess is that your images are not correctly referenced on your web server. Try using explicit paths from the server root on both your local and remote machine, and try to have both machines mirror each other's folder structure.

img tag doesn't have any closing pair like < / img>. try this code
<div id="collapse">
<img src="img/arrowDown.png" id="expandAll" onMouseOver="DownChange();" onMouseOut="DownGoBack();" onClick="openAll();" />
<img src="img/arrowUp.png" id="collapseAll" onMouseOver="UpChange();" onMouseOut="UpGoBack();" onClick="closeAll();" />
</div>
if that doesn't work then try to find if the images are in the correct folder or the names of the images are correct.
Edit:
I used this code and working fine on mozilla firefox and IE 6 -
<script type="text/javascript">
<!--
var images= new Array();
images[0] = "img/ArrowDown.png";
images[1] = "img/ArrowDownHover.png";
images[2] = "img/ArrowUp.png";
images[3] = "img/ArrowUpHover.png";
function DownChange()
{
document.getElementById("expandAll").src = images[1];
}
function DownGoBack()
{
document.getElementById("expandAll").src = images[0];
}
function UpChange()
{
document.getElementById("collapseAll").src = images[3];
}
function UpGoBack()
{
document.getElementById("collapseAll").src = images[2];
}
-->
</script>
<div id="collapse">
<img src="img/arrowDown.png" id="expandAll" onMouseOver="DownChange();" onMouseOut="DownGoBack();" onClick="openAll();" />
<img src="img/arrowUp.png" id="collapseAll" onMouseOver="UpChange();" onMouseOut="UpGoBack();" onClick="closeAll();" />
</div>

Javascript get image source and inject into another image source

I've been working on a Javascript photo gallery and I want it to be very user-friendly. This involves only having to use one image and one link per image. I have it so all the images appear in a scrolling div on the left and onClick it is suppose to change the image source on the right but I can't seem to get javascript to get the image source from the original image and change the second one with it. I've tried a few other ways but this is the way I like and if I could get it to work it would be perfect.
This is inside a table so it is align differently I'm just giving the code needed.
This code was given below but it seems as though he deleted his answer. I think you were much close than me!
Javascript:
<script type="Text/javscript">
function setImage(this) {
document.getElementById("ImageFrame").src = this.childNodes[0].src;
}
</script>
break
<div style="width:275;height:400;overflow-x:scroll;">
<img class="gallery" src="JCF/PICT0421.jpg" />
<img class="gallery" src="JCF/PICT0422.jpg" />
<img class="gallery" src="JCF/PICT0423.jpg" />
</div>
The image being changed.
<div>
<img id="ImageFrame" src="JCF/PICT0421.jpg" width="400" />
</div>

here is a working example. NOTE: a.getElementsByTagName('img')[0].src as different browsers would add nodes to tag before and after the child tag. It is safe to use getElementsByTagName('img')[0].src
<html>
<head>
<script type="text/javascript">
function setImg(a){
//alert(a.getElementsByTagName('img')[0].src);
document.getElementById('ImageFrame').src =
a.getElementsByTagName('img')[0].src
}
</script>
</head>
<body>
<img src="JCF/PICT0421.jpg">
<div>
<img id="ImageFrame" src="JCF/PICT0421.jpg" width="400" />
</div>
</body>
</html>

var pic1 = document.getElementById("image1");
var src = pic1.src; // here is the src for image1
var pic2 = document.getElementById("image2");
pic1.src = src; // here we set the src for image2
So this code will take the image src from image1 and put it in image2.

I believe something like this should work for you:
HTML:
<img class="gallery" id="image1" src="image1.jpg" />
Javascript:
function setImage(imgParent) {
document.getElementById("ImageFrame").src = imgParent.childNodes[0].src;
}​
Live DEMO
The Demo will work better when you actually load in images. However, if you inspect the broken images, you can see that it is loading in the new image correctly.
Edit:
Since Kaf mentioned that he has had issues with childNodes, you may want to try this out instead:
Javascript:
function setImage(imgParent) {
document.getElementById("ImageFrame").src = imgParent.getElementsByTagName('img')[0].src;
}​

assuming you can use Jquery
$('.imageClass').click(function(){
var srcToCopy = $(this).attr('src');
$(somewheretoputsrc).attr('src', srcToCopy);
})
this code should work
edit : fiddle edited with working image
http://jsfiddle.net/jbduzan/b7adx/1/

You should go with so called "Unobtrusive JavaScript", i.e. don't mix content with JavaScript and apply the desired behaviors after the window has been loaded.
Something like that:
function addDomListener(element, eventName, listener) {
if (element.addEventListener) // most browsers
element.addEventListener(eventName, listener, true);
else if (element.attachEvent) // IE
element.attachEvent('on' + eventName, listener);
}
window.onload = function() {
var elements = getElementsByClassName('thumb-link');
for (int i=0; i < elements.size(); i++) {
var el = elements[i];
addDomListener(el, "click", function () {
setImage(el);
});
}
}
getElementsByClassName still needs an implementation here and every a tag that had onlick previously needs the class 'thumb-link'. But I'm sure you'll figure that out.
Using a library like jQuery or Prototype.js would make it easier here...

I need to create an Image element in an html form with all its attribute using javascript how could i do it?

i have a form in which I want to display a loader image only if the file upload field has any path in it, for that i thought of creating the image element in java script along with attributes: src, id and alt..
i am not aware of how to create elements using javascript. please help me.

This page has a good tutorial on dynamically creating DOM elements using javascript.
The standard way to do it is with the document.createElement function.

Small example which adds html code to a placeholder.
<script>
function example()
{
placeholder.innerHTML = "<img src='imagehere'/>";
}
</script>
<input type="button" value="Click" onclick="example();"/>
<div id="placeholder"/>

Using Jquery makes this nice and easy:
Javascript:
$('#MyElementID').html('<img alt="" src="Images/myimage.jpg" />');
HTML:
<div id="MyElementID"></div>
Renders as:
<div id="MyElementID"><img alt="" src="Images/myimage.jpg" /></div>