The target
read-only property of the ResizeObserverEntry
interface returns a reference to the Element
or SVGElement
that is being observed.
Syntax
var element = ResizeObserverEntry.target; var svgElement = ResizeObserverEntry.target;
Value
An Element
or SVGElement
representing the element being observed.
Examples
The following snippet is taken from the resize-observer-border-radius.html (see source) example. This example includes a green box, sized as a percentage of the viewport size. When the viewport size is changed, the box's rounded corners change in proportion to the size of the box. We could just implement this using border-radius
with a percentage, but that quickly leads to ugly-looking elliptical corners; this solution gives you nice square corners that scale with the box size.
To grab a reference to the observed element so we can update its border-radius
value after each change, we make use of the target
property of each entry — entry.target.style.borderRadius
.
const resizeObserver = new ResizeObserver(entries => { for (let entry of entries) { if(entry.contentBoxSize) { entry.target.style.borderRadius = Math.min(100, (entry.contentBoxSize.inlineSize/10) + (entry.contentBoxSize.blockSize/10)) + 'px'; } else { entry.target.style.borderRadius = Math.min(100, (entry.contentRect.width/10) + (entry.contentRect.height/10)) + 'px'; } } }); resizeObserver.observe(document.querySelector('div'));
Specifications
Specification | Status | Comment |
---|---|---|
Resize Observer The definition of 'target' in that specification. |
Editor's Draft | Initial definition. |
Browser compatibility
Desktop | Mobile | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
target | Chrome Full support 64 | Edge Full support 79 | Firefox Full support 69 | IE No support No | Opera Full support Yes | Safari No support No | WebView Android Full support 64 | Chrome Android Full support 64 | Firefox Android No support No | Opera Android Full support Yes | Safari iOS No support No | Samsung Internet Android Full support 9.0 |
Legend
- Full support
- Full support
- No support
- No support