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element()

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 can be viewed live 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; transform: 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!".

example1.png

A somewhat more bizarre example

This example uses a hidden <button> element in a repeating pattern as its background. This demonstrates that you can use arbitrary elements as background, but doesn't necessarily demonstrate good design practices.

<div style="width:400px; height:100px; background:-moz-element(#myBackground2);">
</div>

<div style="overflow:hidden; height:0;">
  <button id="myBackground2" type="button">Evil button!</button>
</div>

example2.png

Specifications

Browser compatibilityUpdate compatibility data on GitHub

Desktop
Chrome Edge Firefox Internet Explorer Opera Safari
element() No No 57
Prefixed
57
Prefixed
Prefixed Implemented with the vendor prefix: -moz-
29 — 57
Prefixed
Prefixed Implemented with the vendor prefix: -moz-
-moz-element() is limited to background-image, background, border-image and border-image-source.
4 — 29
Prefixed
Prefixed Implemented with the vendor prefix: -moz-
-moz-element() is limited to background-image and background.
No No No
Mobile
Android webview Chrome for Android Firefox for Android Opera for Android Safari on iOS Samsung Internet
element() No No 60
Prefixed
60
Prefixed
Prefixed Implemented with the vendor prefix: -moz-
29 — 60
Prefixed
Prefixed Implemented with the vendor prefix: -moz-
-moz-element() is limited to background-image, background, border-image and border-image-source.
4 — 29
Prefixed
Prefixed Implemented with the vendor prefix: -moz-
-moz-element() is limited to background-image and background.
No No No

See also

© 2005–2020 Mozilla and individual contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/CSS/element()