element()
Limited availability
This feature is not Baseline because it does not work in some of the most widely-used browsers.
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.
Formal syntax
<element()> =
element( <id-selector> )
<id-selector> =
<hash-token>
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 id="target-box"> <p>This box uses the element with the #my-background ID as its background!</p> </div> <div id="background-container"> <div id="my-background"> <p>This text is part of the background. Cool, huh?</p> </div> </div> #target-box { width: 400px; height: 400px; background: -moz-element(#my-background) no-repeat; } #background-container { overflow: hidden; height: 0; } #my-background { width: 1024px; height: 1024px; background-image: linear-gradient(to right, red, orange, yellow, white); } #my-background p { transform-origin: 0 0; rotate: 45deg; color: white; } The <div> element with the ID "my-background" is used as the background for the content including the paragraph "This box uses the element with the #my-background 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
| Specification |
|---|
| CSS Images Module Level 4 # element-notation |