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element()

Experimental: This is an experimental technology
Check the Browser compatibility table carefully before using this in production.

The element() CSS function defines an <image> value generated from an arbitrary HTML element. This image is live, meaning that if the HTML element is changed, the CSS properties using the resulting value are automatically updated.

A particularly useful scenario for using this would be to render an image in an HTML <canvas> element, then use that as a background.

On Gecko browsers, you can use the non-standard document.mozSetImageElement() method to change the element being used as the background for a given CSS background element.

Syntax

element(id)

where:

id

The ID of an element to use as the background, specified using the HTML attribute #id on the element.

Examples

These examples work in builds of Firefox that support -moz-element().

A somewhat realistic example

This example uses a hidden <div> as a background. The background element uses a gradient, but also includes text that is rendered as part of the background.

<div
  style="width:400px; height:400px; background:-moz-element(#myBackground1) no-repeat;">
  <p>This box uses the element with the #myBackground1 ID as its background!</p>
</div>

<div style="overflow:hidden; height:0;">
  <div
    id="myBackground1"
    style="width:1024px; height:1024px; background-image: linear-gradient(to right, red, orange, yellow, white);">
    <p style="transform-origin:0 0; rotate: 45deg; color:white;">
      This text is part of the background. Cool, huh?
    </p>
  </div>
</div>

The <div> element with the ID "myBackground1" is used as the background for the content including the paragraph "This box uses the element with the #myBackground1 ID as its background!".

Page Preview

This example based on Vincent De Oliveira's creates a preview of the <div id="css-source"> inside <div id="css-result">.

HTML

<div id="css-source">
  <h1>Page Preview</h1>
</div>
<div id="css-result"></div>

CSS

#css-result {
  background: -moz-element(#css-source) no-repeat;
  width: 256px;
  height: 32px;
  background-size: 80%;
  border: dashed;
}

Result

Specifications

Browser compatibility

Desktop Mobile
Chrome Edge Firefox Internet Explorer Opera Safari WebView Android Chrome Android Firefox for Android Opera Android Safari on IOS Samsung Internet
element() No No 57
29–57-moz-element() is limited to background-image, background, border-image and border-image-source.
4–29-moz-element() is limited to background-image and background.
No No No No No 60
29–60-moz-element() is limited to background-image, background, border-image and border-image-source.
4–29-moz-element() is limited to background-image and background.
No No No

See also

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https://developer.mozilla.org/en-US/docs/Web/CSS/element()