The naturalHeight
read-only property of the PerformanceElementTiming
interface returns the intrinsic height of the image element.
An unsigned 32-bit integer (unsigned long) which is the intrinsic height of the image if this is applied to an image, 0
for text.
In this example an <image>
element is being observed by adding the elementtiming
attribute. A PerformanceObserver
is registered to get all performance entries of type "element"
and the buffered
flag is used to access data from before observer creation. The image file has a width of 1000px and a height of 750px. Calling entry.naturalHeight
returns 750
, that being the intrinsic height in pixels.
<img
src="image.jpg"
alt="a nice image"
elementtiming="big-image"
id="myImage" />
const observer = new PerformanceObserver((list) => {
list.getEntries().forEach((entry) => {
if (entry.identifier === "big-image") {
console.log(entry.naturalHeight);
}
});
});
observer.observe({ type: "element", buffered: true });