I'm trying to change the class name of my header when I hover over it. The class name when NOT hovering is ".l-header.pos_fixed.bg_transparent.shadow_wide", but I'd like to rename it when hovering to ".l-header.pos_fixed.bg_solid.shadow_wide".
Is this possible?
EDIT: Maybe a bit more background information: I want to change the header of https://pinkypromise.pictures to the header of, for example, https://pinkypromise.pictures/contact when hovering on the home page.
To answer your question, yes, it is possible to change class names based on events (hover, in this case), but you will need javascript for that. You can't achieve this with pure css.
As others have mentioned, it is usually a better approach to have a css rule with the :hover pseudo-class. But also be aware that you might have problems with the intended result in touch devices.
A good source of information for these rules is Mozilla Developer Network. Please have a look at the full documentation for :hover's pseudo class on MDN.
Sorry I thought only the logo should change.
I see you site is using jQuery.
When I enter this in the console it seems to work fine:
jQuery('.l-header.pos_fixed.bg_transparent.shadow_wide').mouseenter(function() {
jQuery(this).removeClass('bg_transparent').addClass('bg_solid');
}).mouseleave(function() {
jQuery(this).addClass('bg_transparent').removeClass('bg_solid');
});
You don't need to change the class name on hover, just specify the styles that you want to apply when you hover:
header:hover {
// place the styles that make the background solid here
}
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>
I want to change the beam looking I thing that appears when you hover over text. However, I've only been able to change the pointer cursor. Is this possible in CSS?
Edit: I wanna change the way the text version of the cursor looks like. Instead of being the I beam, I want it to be a custom image. Is this possible?
you need to use css to style the cursor with " cursor: someStyleName "
ex that makes it a crosshair:
span.myclass {
cursor: crosshair;
}
this link shows a use (in html, but the code is the same in css) and a demo of what it looks like, as well as many of the different style types:
https://www.w3schools.com/cssref/tryit.asp?filename=trycss_cursor
ps: this site in general is great for web dev info.. even java/jquery stuff.
I am trying to show the information in the notice class.
I have try adding content: but this doesn't work.
.notice {
color:red;
content: "information below are instructions for this method for this page";
}
<div class="notice"></div>
I was wondering if the text in the content can be shown in the div?. I want to show actually what is in the notice class whenever I call the notice class. I have about 40 pages I need to do this to and some people might thing I should just type it in all pages but that information in the content changes.
Is they a way to do this in css?
The content property only works on the :after and :before psuedo classes, e.g. try:
.notice {
color:red;
}
.notice:after{
content: "information below are instructions for this method for this page";
}
<div class="notice"></div>
See this fiddle
That said, CSS should be kept for styling and not content - which should be output in your HTML, and controlled by either whichever serverside tech you're using (e.g. PHP, Python), or a JS bridge.
I think i your case it is better to make a PHP if statement for the notice. that would be pretty more usefull
I use CMS for client and client doesn't know CSS he use WYSIWYG editor to put content in pages. Client adds Paragraphs, images, images in paragraph (left or right floated), ordered and unordered list, Tables. Problems comes when he want to add images in paragraph (left or right floated). and without adding css class it's not possible. And i don't want to add <div> in content because WYSIWYG editor can't manage div and client works in WYSIWYG mode.
How to style content of pages without using css class?
You will need your user to add a CSS class/style attribute to the image somehow - without adding something to the image to tell it to float right or left it won't float right or left.
If your question is how the client can add the class without having to manually edit the HTML I reckon the only way is to dive into the WYSIWYG editor's javascript and write something a bit like this towards the end of the image-adding process:
var alignment = prompt("Type l to align the picture to the left, and r to align the picture to the right","l").strToLower();
if(alignment == 'r')
{
//line of code to add class "right" to the image tag
} else {
//line of code to add class "left" to the image tag
}
What the code to add the classes should depend on how the WYSIWYG editor works
You can try using element selectors or ID selectors to add styles to HTML elements without referencing CSS class in them.
Element selector would add border to all images on the page:
img { border:1px; }
ID selector would do the same only to image with ID 'image1':
img #image1 { border:1px; }
Still you will need to reference the stylesheet from your page.
There are lots of different ways you can make CSS Selectors that don't require CSS classes. For example, to make a rule that applies to all img tags inside p tags, you could write this:
p img { float: left; }
But how are you hoping to determine which images need to be right-aligned and which images need to be left aligned? Does that data exist in the document in any machine readable format?
A WYSWYG should have "align" property for an image (at least those I have seen). You can then use CSS attribute selector img [align=left] { float:left; } or img [align=right] {float:right;} This wont work on IE 6,7 though, you can use JavaScript to mimic this for those browsers.