[css] Select elements by attribute in CSS

Is it possible to select elements in CSS by their HTML5 data attributes (for example, data-role)?

It's also possible to select attributes regardless of their content, in modern browsers

with:

[data-my-attribute] {
   /* Styles */
}

[anything] {
   /* Styles */
}

For example: http://codepen.io/jasonm23/pen/fADnu

Works on a very significant percentage of browsers.

Note this can also be used in a JQuery selector, or using document.querySelector

Is it possible to select elements in CSS by their HTML5 data attributes? This can easily be answered just by trying it, and the answer is, of course, yes. But this invariably leads us to the next question, 'Should we select elements in CSS by their HTML5 data attributes?' There are conflicting opinions on this.

In the 'no' camp is (or at least was, back in 2014) CSS legend Harry Roberts. In the article, Naming UI components in OOCSS, he wrote:

It’s important to note that although we can style HTML via its data-* attributes, we probably shouldn’t. data-* attributes are meant for holding data in markup, not for selecting on. This, from the HTML Living Standard (emphasis mine):

"Custom data attributes are intended to store custom data private to the page or application, for which there are no more appropriate attributes or elements."

The W3C spec was frustratingly vague on this point, but based purely on what it did and didn't say, I think Harry's conclusion was perfectly reasonable.

Since then, plenty of articles have suggested that it's perfectly appropriate to use custom data attributes as styling hooks, including MDN's guide, Using data attributes. There's even a CSS methodology called CUBE CSS which has adopted the data attribute hook as the preferred way of adding styles to component 'exceptions' (known as modifiers in BEM).

Thankfully, the WHATWG HTML Living Standard has since added a few more words and even some examples (emphasis mine):

Custom data attributes are intended to store custom data, state, annotations, and similar, private to the page or application, for which there are no more appropriate attributes or elements.

In this example, custom data attributes are used to store the result of a feature detection for PaymentRequest, which could be used in CSS to style a checkout page differently.

Authors should carefully design such extensions so that when the attributes are ignored and any associated CSS dropped, the page is still usable.

TL;DR: Yes, it's okay to use data-* attributes in CSS selectors, provided the page is still usable without them.

It's worth noting CSS3 substring attribute selectors

[attribute^=value] { /* starts with selector */
/* Styles */
}

[attribute$=value] { /* ends with selector */
/* Styles */
}

[attribute*=value] { /* contains selector */
/* Styles */
}

    [data-value] {
  /* Attribute exists */
}

[data-value="foo"] {
  /* Attribute has this exact value */
}

[data-value*="foo"] {
  /* Attribute value contains this value somewhere in it */
}

[data-value~="foo"] {
  /* Attribute has this value in a space-separated list somewhere */
}

[data-value^="foo"] {
  /* Attribute value starts with this */
}

[data-value|="foo"] {
  /* Attribute value starts with this in a dash-separated list */
}

[data-value$="foo"] {
  /* Attribute value ends with this */
}

You can combine multiple selectors and this is so cool knowing that you can select every attribute and attribute based on their value like href based on their values with CSS only..

Attributes selectors allows you play around some extra with id and class attributes

Here is an awesome read on Attribute Selectors

Fiddle

a[href="http://aamirshahzad.net"][title="Aamir"] {_x000D_
  color: green;_x000D_
  text-decoration: none;_x000D_
}_x000D_
_x000D_
a[id*="google"] {_x000D_
  color: red;_x000D_
}_x000D_
_x000D_
a[class*="stack"] {_x000D_
  color: yellow;_x000D_
}

<a href="http://aamirshahzad.net" title="Aamir">Aamir</a>_x000D_
<br>_x000D_
<a href="http://google.com" id="google-link" title="Google">Google</a>_x000D_
<br>_x000D_
<a href="http://stackoverflow.com" class="stack-link" title="stack">stack</a>

Browser support:
IE6+, Chrome, Firefox & Safari

You can check detail here.