CSS set background-image by data-image attr

Question

I have sort of elements with this pattern:

<div data-image="{imageurl}" ...></div>

I want to set this elements background-image to data-image. I test this CSS code:

div[data-image] {
    border: 2px solid black;
    background-image: attr(data-image url);
}

border show correctly but nothing happened for background How can do I fix this code only with css (not js or jq)?

Answer 1

As of writing, the browser support of attr() notation on CSS properties other than content - like background-image - is very limited.

Besides, as per CSS level 2 spec, combining url() and attr() is not valid:
content: url(attr(data-image));.

Hence there is no cross-browser CSS solution at the moment to achieve the desired result. Unless using JavaScript is an option:

var list = document.querySelectorAll("div[data-image]");

for (var i = 0; i < list.length; i++) {
  var url = list[i].getAttribute('data-image');
  list[i].style.backgroundImage="url('" + url + "')";
}

div[data-image] {
  width: 100px; height: 100px; /* If needed */
  border: 2px solid black;
}

<div data-image="http://placehold.it/100"></div>

Answer 2

In your HTML:

<div data-image="path_to_image/image_file.extension" ... ></div>

In your CSS:

div:after {
    background-image : attr(data-image url);
    /* other CSS styling */
}

Problems:

This is your required answer. Check this documentation in w3.org. But the main problem is it won't work, not yet!. In many browsers, attr() runs successfully when it is used in content: attribute of the CSS coding. But using it in other attributes of CSS, it doesn't work as expected, not even in major browsers.

Solution:

• Use scripts such as JavaScript or jQuery.

References:

• W3C attr()
• MDN attr()

Thanks:

• Hashem Qolami for correcting my syntax. :)

Answer 3

a nice alternative to data- attributes (or the attr() approach in general) can be the use of custom properties (MDN, csswg, css-tricks).

as their values are not restricted to strings, we can pass around any type that is allowed as a custom property value!

also, you get the benefit of updating these properties at runtime, with a swap of a stylesheet.

.kitten {
  width: 525px;
  height: 252px;
  background-image: var(--bg-image);
}

<div  class="kitten"
      style="--bg-image: url('http://placekitten.com/525/252');">
</div>

Answer 4

If the goal is being able to set the background-image style of an HTML element from within the HTML document rather than the CSS definition, why not use the inline style attribute of the HTML element?

div[style^='background-image'] {
  width:400px;
  height:225px;
  background-repeat:no-repeat;
  background-size:contain;
  background-position:center center;
  /* background-image is not set here... */
}

<!-- ... but here -->
<div style="background-image:url(http://img01.deviantart.net/5e4b/i/2015/112/c/5/mandelbrot_62____courage_to_leave___by_olbaid_st-d646sjv.jpg)"></div>

EDIT:

If selecting the <div> by style is not an option, you may be able to give it a class and select it by class name.