CSS - Add Color with a data attribute - attr(data-

Question

I'm trying to add color to different element with a data attribute in my css but doensn't work ...

I follow this instructions :

The attr() Function: Properties Values Collected from the Edited Document.

W3C

HTML

<table>
    <tr>
        <td>
            <span class="bgborder" data-color="#e7663f"></span>
            <i class="fa fa-copy"></i>
        </td>
        <td>
            <span>Blaablaaablaaa</span>
        </td>
    </tr>
</table>
<table>
    <tr>
        <td>
            <span class="bgborder" data-color="#77c385"></span>
            <i class="fa fa-upload fa-fw"></i>
        </td>
        <td>
            <span>Blablaablaaa</span>
        </td>
    </tr>
</table>

CSS

.bgborder {
    display: block;
    width: 5px;
    height: 100%;
    position: absolute;
    top: 0;
    background-color: attr(data-color color);
}

Nothing appears...Am I right ?

In my chrome inspector I have this :

background-color: attr(data-color color); 
/!\ Invalid property value

I don't understand why... ???

Thanks for your help :)

Answer 1

You can pass css values from html:

<button style="
    --tooltip-string: 'Ug. Tooltips.';
    --tooltip-color: #f06d06;
    --tooltip-font-size: 11px;
    --tooltip-top: -10px">
  Button
</button>

to css:

button::after {
  content: var(--tooltip-string);
  color: var(--tooltip-color);
  font-size: var(--tooltip-font-size);
}

source: https://css-tricks.com/css-attr-function-got-nothin-custom-properties/ codepen: https://codepen.io/chriscoyier/pen/EbxVME

Answer 2

Always a good idea to read the documentation: https://developer.mozilla.org/en/docs/Web/CSS/attr

Surprise! If nothing supports it, then it won't work ;)

Alternative: If you know you only have a limited range of colours, try:

[data-color=red] {background-color:red !important}
[data-color=blue] {background-color:blue !important}
[data-color=zophan-blue] {background-color:#33ccff !important}

As you can see, this allows flexibility, such as defining your own colours ;)

Answer 3

I guess that you are looking is CSS variables and you can use at Chrome, Firefox and Safari. Check the browser support at Can I use

And can see more at the video from Lea Verou

Answer 4

If you are talking only about colors, you can use currentColor value as a proxy.

For example:

HTML

<td>
   <span class="bgborder" style="color: #e7663f"></span>
   <i class="fa fa-copy"></i>
</td>

CSS

.bgborder {
  background-color: currentColor;
}

Answer 5

Currently, the CSS attr function can only be used with the content property in browsers

See here for compatibility

Per the CSS2 spec:

Limited to the content property

CSS3 will extend this (proposal)

..can be used on all properties; may return other values than <string>