This is one I have not had to tackle before. I need to use alt tags on all images in a site including those used by CSS background-image attribute.
There is no CSS property like this as far as I know, so what is the best way to do this please?
Background images sure can present data! In fact, this is often recommended where presenting visual icons is more compact and user-friendly than an equivalent list of text blurbs. Any use of image sprites can benefit from this approach.
It is quite common for hotel listings icons to display amenities. Imagine a page which listed 50 hotel and each hotel had 10 amenities. A CSS Sprite would be perfect for this sort of thing -- better user experience because it's faster. But how do you implement ALT tags for these images? Example site.
The answer is that they don't use alt text at all, but instead use the title attribute on the containing div.
HTML
<div class="hotwire-fitness" title="Fitness Centre"></div>
CSS
.hotwire-fitness {
float: left;
margin-right: 5px;
background: url(/prostyle/images/new_amenities.png) -71px 0;
width: 21px;
height: 21px;
}
According to the W3C (see links above), the title attribute serves much of the same purpose as the alt attribute
Title
Values of the title attribute may be rendered by user agents in a variety of ways. For instance, visual browsers frequently display the title as a "tool tip" (a short message that appears when the pointing device pauses over an object). Audio user agents may speak the title information in a similar context. For example, setting the attribute on a link allows user agents (visual and non-visual) to tell users about the nature of the linked resource:
alt
The alt attribute is defined in a set of tags (namely, img, area and optionally for input and applet) to allow you to provide a text equivalent for the object.
A text equivalent brings the following benefits to your website and its visitors in the following common situations:
nowadays, Web browsers are available in a very wide variety of platforms with very different capacities; some cannot display images at all or only a restricted set of type of images; some can be configured to not load images. If your code has the alt attribute set in its images, most of these browsers will display the description you gave instead of the images
some of your visitors cannot see images, be they blind, color-blind, low-sighted; the alt attribute is of great help for those people that can rely on it to have a good idea of what's on your page
search engine bots belong to the two above categories: if you want your website to be indexed as well as it deserves, use the alt attribute to make sure that they won't miss important sections of your pages.
In this Yahoo Developer Network (archived link) article it is suggested that if you absolutely must use a background-image instead of img element and alt attribute, use ARIA attributes as follows:
<div role="img" aria-label="adorable puppy playing on the grass">
...
</div>
The use case in the article describes how Flickr chose to use background images because performance was greatly improved on mobile devices.
I think you should read this post by Christian Heilmann. He explains that background images are ONLY for aesthetics and should not be used to present data, and are therefore exempt from the rule that every image should have alternate-text.
Excerpt (emphasis mine):
CSS background images which are by definition only of aesthetic value
– not visual content of the document itself. If you need to put an
image in the page that has meaning then use an IMG element and give it
an alternative text in the alt attribute.
I agree with him.
As mentioned in other answers, there is no (supported) alt attribute for a div tag only for the img tag.
The real question is why you need to add the alt attribute to all background images for the site? Based on this answer, it will help you determine which route to take in your approach.
Visual/Textual: If you are simply attempting to add a textual fall back for the user if the image fails to load, simply use the title attribute. Most browsers will provide a visual tool tip(message box) when a user hovers over the image, and if the image is not loaded for whatever reason, it behaves the same as an alt attribute presenting text when image fails. This technique still allows for the site to speed up load times by keeping images set to backgrounds.
Screen Readers: The middle of the road option, this varies because technically keeping your images as backgrounds and using the title attribute approach should work as hinted above, "Audio user agents may speak the title information in a similar context." However this is not guaranteed to work in all cases, including some readers may ignore it all together. If you end up opting for this approach, you can also try adding in aria-labels to help ensure screen readers pick these up.
SEO/Search Engines: Here is the big one, if you were like me, you added your background images, all was good. Then months later the customer(or maybe yourself) realized that you are missing out on some prime SEO gold by not having alt's for your images. Keep in mind, the title attribute does not have any weight on search engines, from my research and as mentioned in an article here: https://www.searchenginejournal.com/how-to-use-link-title-attribute-correctly/. So if you are aiming for SEO, then you will need to have an img tag with the alt attribute. One possible approach is to just load very small actual images on the site with alt attributes, this way you get all the SEO and don't have to readjust the existing CSS in place. However this may lead to additional load time depending on the size and google does indeed look at the images path when indexing. In short if you are going this route, just accept what has to be done and include the actual images instead of using backgrounds.
The general belief is that you shouldn't be using background images for things with meaningful semantic value so there isn't really a proper way to store alt data with those images. The important question is what are you going to be doing with that alt data? Do you want it to display if the images don't load? Do you need it for some programmatic function on the page? You could store the data arbitrarily using made up css properties that have no meaning (might cause errors?) OR by adding in hidden images that have the image and the alt tag, and then when you need a background images alt you can compare the image paths and then handle the data however you want using some custom script to simulate what you need. There's no way I know of to make the browser automatically handle some sort of alt attribute for background images though.
This article from W3C tells you what they think you should do
https://www.w3.org/WAI/GL/wiki/ARIATechnique_usingImgRole_with_aria-label_forCSS-backgroundImage
and has examples here
http://mars.dequecloud.com/demo/ImgRole.htm
among which
<a href="http://www.facebook.com">
<span class="fb_logo" role="img" aria-label="Connect via Facebook">
</span>
</a>
Still, if, like in the above example, the element containing the background image is just an empty container, I personally prefer to put the text in there and hide it using CSS; right where you show the image instead:
<a href="http://www.facebook.com"><span class="fb_logo">
Connect via Facebook
</span></a>
.fb_logo {
height: 37px; width: 37px;
background-image: url('../gfx/logo-facebook.svg');
color:transparent; overflow:hidden; /* hide the text */
}
The classical way to achieve this is to put the text into the div and use an image replacement technique.
<div class"ir background-image">Your alt text</div>
with background-image beeing the class where you assign the background image and ir could be HTML5boilerplates image replacement class, below:
/* ==========================================================================
Helper classes
========================================================================== */
/*
* Image replacement
*/
.ir {
background-color: transparent;
border: 0;
overflow: hidden;
/* IE 6/7 fallback */
*text-indent: -9999px;
}
.ir:before {
content: "";
display: block;
width: 0;
height: 150%;
}
Here's my solution for Immediate fix:
Once the background image is removed the alt text will be visible from Img tag.
.alt-image {
position: absolute;
top: 0;
left: 0;
z-index: -1;
}
.background-image{
background:url("https://www.w3schools.com/images/picture.jpg") no-repeat;
width:100%;
height:500px;
position:relative;
}
<div role="img" aria-label="place alt text here" title="place alt text here" class="background-image">
<img src="" alt="place alt text here" class="alt-image"/>
</div>
Here's my solution to this type of problem:
Create a new class in CSS and position off screen. Then put your alt text in HTML right before the property that calls your background image. Can be any tag, H1, H2, p, etc.
CSS
<style type="text/css">
.offleft {
margin-left: -9000px;
position: absolute;
}
</style>
HTML
<h1 class="offleft">put your alt text here</h1>
<div class or id that calls your bg image> </div>
It''s not clear to me what you want.
If you want a CSS property to render the alt attribute value, then perhaps you're looking for the CSS attribute function for example:
IMG:before { content: attr(alt) }
If you want to put the alt attribute on a background image, then ... that's odd because the alt attribute is an HTML attribute whereas the background image is a CSS property. If you want to use the HTML alt attribute then I think you'd need a corresponding HTML element to put it in.
Why do you "need to use alt tags on background images": is this for a semantic reason or for some visual-effect reason (and if so, then what effect or what reason)?
You can achieve this by putting the alt tag in the div were your image will appear.
Example:
<div id="yourImage" alt="nameOfImage"></div>
How can I add CSS to github's markdown language?
I've been able to do so by using the style property inside html tags, like:
<p style="text-align: center;">This is some random text</p>
But if I move the css to the beginning, like:
<style>
p {
text-align: center;
}
</style>
<p>This is some random text</p>
Github doesn't recognize it, and just writes to the screen the css code.
I'm using Atom, and the package Markdown Preview actually recognizes this correctly, even though on the remote repository it shows wrong. And so does the Google Chrome extension Markdown Preview Plus.
Is there a way to do this? Writing css within html tags just feels plain wrong.
After GitHub converts Markdown to HTML,
The HTML is sanitized, aggressively removing things that could harm you and your kin—such as script tags, inline-styles, and class or id attributes. See the sanitization filter for the full whitelist.
style tags are not included in GitHub's whitelist, so they are removed. I'm actually surprised that inline style attributes work; they don't seem to be included in the whitelist, either, and are explicitly mentioned in the previous paragraph.
In any case, GitHub does not permit arbitrary HTML to be included in Markdown.
Here is how you can accomplish what you're looking for. As the other answer states, Github doesn't support this syntax, but if you pop this Markdown into another preview tool you'll see that the bullets are removed from this list.
|Signal|Description|
|---|---|
|DOP|Horizontal Dilution of precision|
|FIX|GPS Fix Quality indicator: <ul style="list-style-type:none;"><li>0 - fix not available</li><li>1 - GPS fix</li></ul>|
Signal
Description
DOP
Horizontal Dilution of precision
FIX
GPS Fix Quality indicator: 0 - fix not available1 - GPS fix
You can trivially override what CSS Github uses by supplying it with your own style.css file, nested as ./assets/css/style.css (which is stylesheet URL that gets pointed to in the HTML source code that Github build off of your markdown).
Note that if you want to just "add" any CSS, you'll want to copy Github's CSS first, so you can create a file with the same content after which you place your own rules. You can find this on any view-source:https://username.github.io/repo-name/assets/css/style.css with the obvious replacements for username and repo-name.
E.g.
/* CSS as copied from github's own stylesheet here, which is all one line anyway */
...
/* And then your own CSS */
/* remove the repo name as some kind of weird super-title */
h1:first-child { display: none }
/* and better emphasise the _real_ title */
h1:nth-child(2) { font-size: 3em; }
/* let's also give images a subtle border */
img { border: 1px solid #DDD; }
I setup a static html landing page; displays perfectly in Chorme, Safari, and Firefox. However, I cannot get the embeded MailChimp contact form name and email fields to display when I use the zoom property; as soon as I remove it, the inputs show up too large and out of place which is why I used the zoom property in the first place.
Why would this cause an error? Is there anyway to rememdy this odd problem?
url: http://comingsoon.veteranbrewingcompany.com/
TIA
You really need to address why the form is so large. Various styles are causing it to be so, such as
#mc_embed_signup .mc-field-group input {
font-size: 40px;
}
#mc_embed_signup .button {
background: url("http://themicroscopeguy.com/wp-content/uploads/2013/05/submit2.png");
width: 207px;
height: 92px;
}
So, you have big font sizes set, and the submit button is quite a large image. You can address all that via CSS. You don't need an image for the subbmit button, as you can easily style a normal button with CSS.
I'm developing an app for use with TideSDK. Obviously, in Chrome, the user can select any html text he sees. However, in TideSDK, it appears that text selection is disabled by default. I imagine a simple setting will allow it, but after Googling and looking in the documentation, I can't find anything to show how to allow the user to select text. Can anyone point me in the right direction?
body, p
{
-webkit-user-select: auto;
}
I tried the code above. it worked...
By default the body loads the -webkit-user-select: auto; in body section of tideSDK so the contents are not selectable
Found the answer. You must use -webkit-user-select: auto|text for the element you want to be selectable. Not sure why text is not selectable by default.
I've been stuck on this for 3 days now.
I have two pages that basically share some code for a search feature on my website, here's my code
The CSS
#btnSearch {
display: block;
color: #ffffff;
width: 100px;
height: 27px;
border: 0;
padding: 0;
background: transparent url("Images/btnSearch2.png");
}
When I'd gotten the one page working, I copied that code to the page where it doesn't work, but it hasn't made any difference, here's the HTML (don't worry about the inline css, that's just for convenience while I'm working on it...)
EDIT1:
All other classes work correctly as they (along with the css above) come from a stylesheet at <webroot>/App_Themes/Default... The images go in a subdirectory of this location.
I don't see why this code works on 1 page and not the other when all the other CSS classes work on both pages...
Have you tried the absolute image path and see if it works that way?
Maybe it´s a Browser problem: Try to open the file that doesn´t work in another browser.
Maybe you have a tag named the same way #btnSearch in the pages where the styles don´t apply.
Is the path to the background image correct for the page where the code doesn't work? Or even the path to the CSS file?