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Creating Facebook share button that is accessibility friendly

Im trying to create a facebook share button for my page that is accessibe by tab-indexing and pressing enter (for accessibility). A lot of the solutions I had created were using javascript and wouldn't load my script until after tabbing out of the share button.
So far I have created this button.
<a tabindex="0" class="fb-share-button" href="javascript:window.location=%22http://www.facebook.com/sharer.php?u=%22+encodeURIComponent(document.location)+%22&t=%22+encodeURIComponent(document.title)" data-layout="button_count">
<img src="/sites/all/themes/saralee/images/icon-facebook.png" alt="facebook icon">
</a>
This almost gives the desired outcome except I need it to open in either a new tab or an iframe. Which I haven't been able to do with keeping a valid url. (since the above button parses the current url). using target="_blank" doesnt work.

Quick Note - The best option would be to build the URL on the server and serve it as part of the HTML, use the JavaScript option below if you are unable to do that for any reason.
All other points other than the URL below are important to make your share 'button' accessible.
Instead of using an inline function on the button, build the URL in a separate JavaScript function and then apply it on document load.
JS
var URL = "http://www.facebook.com/sharer.php?u=%22+encodeURIComponent(document.location)+%22&t=%22+encodeURIComponent(document.title)";
var elements = document.getElementsByClassName("fb-share-button");
elements[0].setAttribute("href", URL); //using [0] to get first element, would be better to use an ID or simply **build the URL on the server before loading the page** and serve it as part of the HTML.
HTML
<a target="_blank" class="fb-share-button" href="fallback URL In Case Of JS Failure" data-layout="button_count">
<img src="/sites/all/themes/saralee/images/icon-facebook.png" alt=""/>
<span class="visually-hidden">Share This Page on Facebook (opens in new window)</span>
</a>
CSS
.visually-hidden {
position: absolute !important;
height: 1px;
width: 1px;
overflow: hidden;
clip: rect(1px 1px 1px 1px); /* IE6, IE7 */
clip: rect(1px, 1px, 1px, 1px);
white-space: nowrap; /* added line */
}
Because you are no longer setting window.location using target="_blank" will work as expected (window.location was overriding the functionality of the link).
Also notice that I removed the tabindex as links are focusable by default (so it isn't needed).
I also changed the alt description to "" and added a 'visually hidden' <span> containing the purpose of the link.
I have included the CSS to make something 'visually-hidden' by applying that class to an item, as it is a useful tool to have in your accessibility toolkit!
Note how I indicated the link 'opens in a new window' within brackets to let screen readers know the behaviour of this link.
An empty alt tag is used to mark an image as decorative (make sure it is empty and not null, i.e. alt="" NOT alt).
Visually Hidden text is still accessible to screen readers but will not show visually.

Search and replace a string with hyperlink

I'm not sure if this is possible but I am helping out with a rather large website that was compiled with .aspx
We are wanting to change a link on the website but there is no actual place to edit the text for the link. I can however use CSS or possibly Javascript to edit the site.
<li>
Other Pages
</li>
<li>
Blue Page
</li>
I want to change the link and text that says Blue Page to something such as Red Page.
example:
<li>
Red Page
</li>
Is it possible to search and replace the text for that hyperlink using CSS?
I have already tried creating an overlay that covers the original text and link but it doesn't position properly on
the page depending on the browser the user uses.
example:
<div id="cover"></div>
#cover {
background: url('../images/cover.png') no-repeat;
top: 80%;
margin-left: 0px;
height: 30px;
width: 203px;
position: relative;
}
Anyone have any other ideas on how I can possibly replace text with CSS or Javascript?

Try something like this with JavaScript,
var bluePage = document.querySelectorAll("a[href='bluepage.aspx']");
if (bluePage[0]) {
bluePage[0].setAttribute("href", "redpage.aspx");
bluePage[0].innerHTML="Red Page";
}

CSS would only change the appearance of the link. The href URI would remain the same underneath, and if a user clicked the link, they'd be taken to the old link location. Hence, you need to use Javascript for this.
As per this answer, you can do search and replace with Javascript like so:
<script type="text/javascript">
function replaceScript() {
var toReplace = 'http://google.com';
var replaceWith ='http://yahoo.com';
document.body.innerHTML = document.body.innerHTML.replace(toReplace, replaceWith);
}
</script>
And you can initialize this function on page load like so:
<body onload="replaceScript();">
That should replace the strings throughout the page. However, the major drawback here is that it only replaces the links on page load. The pages saved on your server will still have the old links, which means there will be a small delay (tens to hundreds of milliseconds, probably) when the user loads any page, because the script needs to do its work, which takes a little bit of time. Also, it won't work if the user has JavaScript disabled in their browser, or if it's visited by a non-browser agent (like bot, crawler or web service), which is less than perfect.

Changing The Size of Twitter's Follow Button?

I'm looking at the new Twitter Follow Button (https://twitter.com/about/resources/followbutton), but unfortunately my sidebar is smaller than the default size, thus throwing my whole site out of whack.
Is there an easy way to hack the script to resize the button, or at least to put a line break between the actual follow button and the account name?

If you look at the page source, then your twitter code converts from
<div class="twitter">
<!-- twitter code here -->
</div>
to
<div class="twitter">
<iframe ...>...</iframe>
</div>
Now it's easy to change the width of the button via css:
.twitter iframe {
width: 80px !important;
}

I'd wrap the button in a container with a nice class name and use CSS to adjust the styling.
.twitter-button-container{
width: 100px;
height:100px;
}
Something like that.
UPDATE
On second thought, it seems that the image is a background image to the anchor tag. I don't think it's possible to resize background images using CSS etc. You'd need to have the image in an img tag.

How to override HTML image using CSS

I have my current code:
#content img[src="/img/test.gif"] {
background-image:url(dark-img.png) !important;
}
From my understanding !important; overrides existing values?
Why isn't this overriding the current HTML image in place there? The background shows up, behind the HTML image.
I want it in front of the HTML image, is this possible using CSS or JS?
Edit: For what its worth, im making a userscript that will modify the existing style of the site. So I do not have direct access to the HTML image.

You don't need javascript for image replacement! As long as you can identify the image by a CSS selector, you can use CSS to do the trick.
See the solution here
http://www.audenaerde.org/csstricks.html#imagereplacecss

Here is the code using only css:
<img src="tiger.jpg"
style="padding: 150px 200px 0px 0px;
background: url('butterfly.jpg');
background-size:auto;
width:0px;
height: 0px;">
sets the image size to 0x0,
adds a border of the desired size (150x200), and
uses your image as a background-image to fill.
If you upvote this answer, give #RobAu's answer an upvote, too.

The replacement of an image in CSS can be done in several ways.
Each of them has some drawbacks (like semantics, seo, browsercompatibility,...)
On this link 9 (nine!) different techniques are discussed in a very good way :
http://css-tricks.com/css-image-replacement/
If you are interested in css in general : the whole site is worth a look.

The background-image property, when applied to an image, refers to (drum roll ... ) the background-image of the image. It will always be behind the image.
If you want the image to appear in front of the image, you are going to have to use two images, or another container with a background-image that covers the first image.
BTW, it is bad practice to rely on !important for overriding. It can also be ineffective since 1) it can't override declarations in an element's style attribute, and 2) it only works if it can work based on the markup and the current CSS. In your case, all the huffing and puffing and !important declarations won't make an image do something it can't do.

I answered a similar question in another SO page..
https://robau.wordpress.com/2012/04/20/override-image-src-in-css/
<img src="linkToImage.jpg" class="egg">
.egg {
width: 100%;
height: 0;
padding: 0 0 200px 0;
background-image: url(linkToImage.jpg);
background-size: cover;
}
So effectively hiding the image and padding down the background. Oh what a hack but if you want an with alt text and a background that can scale without using Javascript?

Use your 'userscript' to change 'src' attribute value.
If there is an ID there, you can do this:
document.getElementById('TheImgId').src = 'yournewimagesrc';
If there is no ID:
var imgElements = document.getElementsByTagName('img');
Do iteration of imgElements. When its src value is match with your criteria, change the value with your own, do break.
Update:
Javascript:
<script language="javascript">
function ChangeImageSrc(oldSrc, newSrc) {
var imgElements = document.getElementsByTagName('img');
for (i = 0; i < imgElements.length; i++){
if (imgElements[i].src == oldSrc){
imgElements[i].src = newSrc;
break;
}
}
}
</script>
HTML:
<img src="http://i.stack.imgur.com/eu757.png" />
<img src="http://i.stack.imgur.com/IPB9t.png" />
<img src="http://i.stack.imgur.com/IPB9t.png" />
<script language="javascript">
setTimeout("ChangeImageSrc('http://i.stack.imgur.com/eu757.png', 'http://i.stack.imgur.com/IPB9t.png')", 5000);
</script>
Preview:
The first image will be replaced after 5 secs. Try Live Demo.

you'll have to place the first image as a background-image too. Then you can override it. You could do in a "standard" css file for the site, and every user gets its own, where he can override what he wants.

i agree with all the answers here, just thought id point out that 'browsers' such as IE won't like the img[src="/img/test.gif"] as a means of selecting the image. it would need a class or id.

The images shown in tags are in the foreground of the element, not the background, so setting a background image in an won't override the image; it'll just appear behind the main image, as you're seeing.
What you want to do is replace the image. Here's your options:
Start with an element with a background image, not an tag. Then changing the background image in CSS will replace it.
Start with an tag, but use Javascript to change the src attribute. (this can't be done in CSS, but is simple enough in JS)
EDIT:
Seeing your edit in the question, I'd suggest option 2 - use Javascript to change the src attribute. It's quite simple; something like this would do the trick:
document.getElementById('myimgelement').src='/newgraphic.jpg';

You should be able to replace it by just doing something like:
.image {
content: url('https://picsum.photos/seed/picsum/400');
width: 200px;
height: 200px;
}
Unfortunately seems that it does not work in Firefox :(

Don't load hidden images

I have a bunch of hidden images on my website. Their container DIVs have style="display: none". Depending on the user's actions, some images may be revealed via javascript. The problem is that all my images are loaded upon opening the page. I would like to put less strain on the server by only loading images that eventually become visible. I was wondering if there was a pure CSS way to do this. Here are two hacky/complicated ways I am currently doing it. As you can see, it's not clean code.
<div id="hiddenDiv">
<img src="spacer.gif" />
</div>
.reveal .img {
background-image: url(flower.png);
}
$('hiddenDiv').addClassName('reveal');
Here is method 2:
<img id="flower" fakeSrc="flower.png" />
function revealImage(id) {
$('id').writeAttribute(
'src',
$('id').readAttribute('fakeSrc')
);
}
revealImage('flower');

The browser will load any images that has a src attribute set, so what you want to do is to use data-src in the markup and use JavaScript to set the src attribute when you want it to load.
<img class="hidden" data-src="url/to/image.jpg" />
I created this tiny plugin that will take care of the problem:
(function($){
// Bind the function to global jQuery object.
$.fn.reveal = function(){
// Arguments is a variable which is available within all functions
// and returns an object which holds the arguments passed.
// It is not really an array, so by calling Array.prototype
// he is actually casting it into an array.
var args = Array.prototype.slice.call(arguments);
// For each elements that matches the selector:
return this.each(function(){
// this is the dom element, so encapsulate the element with jQuery.
var img = $(this),
src = img.data("src");
// If there is a data-src attribute, set the attribute
// src to make load the image and bind an onload event.
src && img.attr("src", src).load(function(){
// Call the first argument passed (like fadeIn, slideIn, default is 'show').
// This piece is like doing img.fadeIn(1000) but in a more dynamic way.
img[args[0]||"show"].apply(img, args.splice(1));
});
});
}
}(jQuery));
Execute .reveal on the image(s) you want to load/show:
$("img.hidden").reveal("fadeIn", 1000);
See test case on jsFiddle.

Here's a jQuery solution:
$(function () {
$("img").not(":visible").each(function () {
$(this).data("src", this.src);
this.src = "";
});
var reveal = function (selector) {
var img = $(selector);
img[0].src = img.data("src");
}
});
It's similar to your solution, except it doesn't use the fakeSrc attribute in the markup. It clears the src attribute to stop it from loading and stores it elsewhere. Once you are ready to show the image, you use the reveal function much like you do in your solution. I apologize if you do not use jQuery, but the process should be transferable to whichever framework (if any) that you use.
Note: This code specifically must be ran before the window has fired the load event but after the DOM has been loaded.

Weirdly, there's no answer about native lazy loading which is implemented in the majority of the browsers already.
you can do it by adding loading="lazy" attribute to your image.
Addy Osmani wrote a great article about it. You can read more about lazy loading here: https://addyosmani.com/blog/lazy-loading/

It partially depends on how your images must be placed in your code. Are you able to display the images as the background of a <div>, or are you required to use the <img> tag? If you need the <img> tag, you may be screwed depending on the browser being used. Some browsers are smart enough to recognize when an image is inside of a hidden object or in an object of 0 width/height and not load it since it's essentially invisible, anyway. For this reason many people will suggest putting an image in a 1x1 pixel <span> if you want the image to be pre-loaded but not visible.
If you don't require the <img> tag, most browsers won't load images referenced by CSS until the element in question becomes visible.
Mind you that short of using AJAX to download the image there's no way to be 100% sure the browser won't pre-load the image anyway. It's not unbelievable that a browser would want to pre-load anything it assumes may be used later in order to "speed up" the average load times.

Using CSS to put the image an unused class, then adding that class to an element with javascript is going to be your best bet. If you don't use image tags at all, this solution becomes a bit more obvious.
Though, for perspective, most people have the opposite problem where they want to preload an image so it shows up instantly when it's told to be shown.

If you are okay relying on scripting, there is the background image method and the image src method. Put simply, set all your hidden images to some very small image (reduce strain on server) or one that does not exist at all (who cares? The visitor cannot see the image-missing [X] anyway, the div is hidden) then change it with script...
<img src="I_do_not_exist.jpg" id="my_image" />
<input type="button" onclick="document.getElementById('my_image').src='I_exist.jpg';" Value="change image" />
<br /><br /><br />
<div id="mydiv" style="width:40px; height:40px; border:2px solid blue"></div>
<input type="button" onclick="document.getElementById('my_div').style.width='455px';document.getElementById('my_div').style.height='75px';document.getElementById('my_div').style.backgroundImage='url(I_exist.jpg)';" Value="change background image" />
I left a width on the above example to show that nothing is in the div image wise until you ask it to load.

If you make the image a background-image of a div in CSS, when that div is set to 'display: none', the image will not load.
You can do the following for a pure CSS solution, it also makes the img box actually behave like an img box in a responsive design setting (that's what the transparent png is for), which is especially useful if your design uses responsive-dynamically-resizing images.
<img style="display: none; height: auto; width:100%; background-image:
url('img/1078x501_1.jpg'); background-size: cover;" class="center-block
visible-lg-block" src="img/400x186_trans.png" alt="pic 1">
The image will only be loaded when the media query tied to visible-lg-block is triggered and display:none is changed to display:block. The transparent png is used to allow the browser to set appropriate height:width ratios for your <img> block (and thus the background-image) in a fluid design (height: auto; width: 100%).
1078/501 = ~2.15 (large screen)
400/186 = ~2.15 (small screen)
So you end up with something like the following, for 3 different viewports:
<img style="display: none; height: auto; width:100%; background-image: url('img/1078x501_1.jpg'); background-size: cover;" class="center-block visible-lg-block" src="img/400x186_trans.png" alt="pic 1">
<img style="display: none; height: auto; width:100%; background-image: url('img/517x240_1.jpg'); background-size: cover;" class="center-block visible-md-block" src="img/400x186_trans.png" alt="pic 1">
<img style="display: none; height: auto; width:100%; background-image: url('img/400x186_1.jpg'); background-size: cover;" class="center-block visible-sm-block" src="img/400x186_trans.png" alt="pic 1">
And only your default media viewport size images load during the initial load, then afterwards, depending on your viewport, images will dynamically load.
And no javascript!