Is there an equivalent to the “alt” attribute for div elements?

问题

Screenreaders will read whatever string is set to the "alt" attribute. The use of this attribute is specifically for image tags.

If I have a div like so:

<div id=myCoolDiv tabindex="0"> 2 <div>

Is there a way to have a screen reader pickup an attribute to read a string the same way an alt tag is used?

So for the div listed below, the screen reader will say ie: "shopping cart items 2"?

I tried using aria-label but the screenreader won't pick it up:

<div id=myCoolDiv tabindex="0" aria-label="shopping cart items"> 2 <div>

回答1:

Try role="listitem" or role="group" and aria-labelledby="shopping cart items". See Example 1. The 2 is text content which should be read by screen reader already with the attribute read as context to the content. Refer to this section.

UPDATE 2

Add aria-readonly=true role=textbox if you use an input. If there are doubts whether to use aria-label or aria-labelledby, read this article. In the documentation for JAWS and testing it myself supports the fact that aria-label is ignored. Furthermore, semantics are very important when accessibility is your concern. Using a div when you could use an input is not semantically sound and like I said before, JAWS would accept a form element more readily than a div. I assume that this "shopping cart" is a form or part of a form, and if you don't like it's borders, input {border: 0 none transparent} or use <output>* which would be A+ as far as semantics are concerned.

Sorry, @RadekPech reminded me; I forgot to add that using aria-labelledby needs visible text and that the text needs an id which is also listed as the value(s) of aria-labelledby. If you don't want text because of aesthetics, use color: transparent, line-height: 0, or color:<same as background>. That should satisfy visibility as far as the DOM is concerned* and still be invisible to the naked eye. Keep in mind these measures are because JAWS ignores aria-label.

*untested

EXAMPLE 3

<span id="shopping">Shopping</span>&nbsp;
<span id="cart">Cart</span>&nbsp;
<span id="items">Items</span>&nbsp;
<input id='cart' tabindex="0" aria-readonly=true readonly role="textbox" aria-labelledby="shopping cart items" value='2'>

UPDATE 1

For JAWS, you probably have to configure it a little:

Click the Utilities menu item.
Then Settings Center.
Speech and Sounds Schemes
Modiy Scheme...
HTML Tab

In this particular dialog box, you can add specific attributes and what is said when an element is tabbed to. JAWS will respond to form elements easier because they can trigger the focus event. You'll have an easier time doing Example 2 instead:

EXAMPLE 1

<div id=myCoolDiv tabindex="0" role="listitem" aria-labelledby="shopping cart items"> 2 <div>

EXAMPLE 2

<input id='semantic' tabindex="0" role="listitem" aria-labelledby="shopping cart items" value='2' readonly>

回答2:

There are two ways (which can be combined) to have screen reader to read alternative text:

Anything with ARIA role img can (MUST) have alt attribute. See WAI-ARIA img role.
```
<div role="img" alt="heart">
♥︎
</div>
```

However this should be used only in case the element really represent an image (e.g. the heart unicode character).

If an element contain actual text, that just need different reading, you should set ARIA role to text and add aria-label with whatever you want to be read by the screen reader. See WAI-ARIA text role.
```
<div role="text" aria-label="Rating: 60%">
Rating: ★★★☆☆︎
</div>
```

Do not mismatch it with aria-labeledby which should contain ID of an related element.

You can combine the previous two cases into one using two ARIA roles and adding both alt and aria-label:
```
<div role="img text" alt="heart" aria-label="heart">
♥︎
</div>
```

When more ARIA roles are defined, browser should use the first one that is supported and process the element with that role.

One last important thing is that you must set page type to HTML5 (which support ARIA by design).

<!DOCTYPE html>

Using HTML4 or XHTML requires special DTD to enable ARIA support.

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML+ARIA 1.0//EN"
   "http://www.w3.org/WAI/ARIA/schemata/xhtml-aria-1.dtd">

回答3:

In case you use Bootstrap Framework there is a quick and easy solution. You should use sr-only or sr-only sr-only-focusable Bootstrap's CSS classes in a span element where your screen-reader-only text will be written.

Check the following example, a span element with class glyphicon glyphicon-shopping-cart is also used as cart icon.

<div id="myCoolDiv">
<h5>
<span class="glyphicon glyphicon-shopping-cart"></span> 2  
<span class="sr-only sr-only-focusable" tabindex="0">shopping cart items</span>
</h5>
<div>

Screen Reader Output: "two shopping cart items"

provided by Fangs Screen Reader Emulator Addon for Firefox

You can find the above working example in this: Fiddle

As suggested by Oriol, in case you don't use Bootstrap Framework then simply add the following in your CSS file.

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  border: 0;
}
.sr-only-focusable:active,
.sr-only-focusable:focus {
  position: static;
  width: auto;
  height: auto;
  margin: 0;
  overflow: visible;
  clip: auto;
}

回答4:

According to the text alternative computation algorithm of the W3C and the Accessible Name and Description: Computation and API Mappings 1.1 you definitely should use aria-label.

That being said, it does not work with Jaws. Text alternative is only computed for elements having an ARIA role.

The remaining option is to use a link that will go to your cart page, using both title and aria-label to satisfy anyone:

<a href="#cart" title="2 shopping cart items" aria-label="2 shopping cart items">2</a>

You can also use a transparent 1 pixel option:

2 <img src="pixel.png" height="1" width="1" alt="shopping cart items" />

回答5:

No, there is no equivalent to an alt attribute for <div> elements.

For what you are trying to do, an ARIA-based solution is overkill. Not only are you bumping into screen reader compatibility problems, you are applying ARIA attributes where they are not needed (and arguably do not belong if on something like a <div>).

Instead, consider using an off-screen technique (such as this one from The Paciello Group or this one from WebAIM). Content hidden using this technique will still be read by screen readers but will be visually hidden.

From reading your question, I think this is what you are after.

I made a pen demonstrating this technique. It may be easier to test in the full-page version.

Edit: Added HTML and CSS from the example, but please note that both the specs and browser / assistive technology support change over time, so if you are reading this in a year you should continue to use the links above to verify this CSS is still the current best practice.

HTML

 <div tabindex="0">
  <span class="offscreen">Items in shopping cart: </span>2
 </div>

CSS

.offscreen {
  position: absolute;
  clip: rect(1px 1px 1px 1px);
  /* for Internet Explorer */
  clip: rect(1px, 1px, 1px, 1px);
  padding: 0;
  border: 0;
  height: 1px;
  width: 1px;
  overflow: hidden;
}

回答6:

Try:

HTML

<div id=myCoolDiv tabindex="0"><span class="aria-hidden">shopping cart items</span>2<div>

CSS

.aria-hidden {
  position: absolute;
  left: -100000px;
}

This will announce the text inside the span. And the Parent div will not lose visual focus. Aria-hidden class will hide the span from the visible screen area but will read it as its inside the div that has focus.

回答7:

You can create a class such as screen-reader-text with the following css:

.screen-reader-text { 
   clip: rect(1px, 1px, 1px, 1px); 
   height: 1px; 
   width: 1px; 
   overflow: hidden; 
   position: absolute !important;
}

Then, in your code, you can just add a <span> with the screenreader text as so:

<div>
I am a div!
<span class="screen-reader-text">This is my screen reader text</span> 
</div>

See an example over here: https://jsfiddle.net/zj1zuk9y/

(Source: http://www.coolfields.co.uk/2016/05/text-for-screen-readers-only-updated/)

回答8:

Use an image inside the div that has the label as its alt attribute. That way, those without screen readers just see the number and an image, whereas those with readers will hear the whole sentence:

<div>
    <img src="http://tny.im/57j" alt="Shopping cart items" />
    2
</div>

Seen as: 2

Read as: "Shopping cart items: 2"

The alt attribute exists for images because there is no way to "read aloud" the content of the image, so the provided text is used instead. But for the div, it already contains text and images. Therefore, if you want it to be read by a screen-reader, you need to include the text and alt text in the content of the div.