onImage

OnImage is not a standard DOM event. It is a naming convention used in various UI libraries and frameworks to denote a callback or event that signals when image data is available, has loaded, or has been processed in some way. Because it is not a universal standard, the exact behavior of onImage depends on the specific library or component that defines it.

In practice, an onImage callback is typically invoked after the image resource has been fetched and is ready for use within the UI. This may mean the image has successfully loaded, has been decoded, or has been prepared for rendering by a component. Some implementations distinguish onImage from the more common onLoad and onError events, using onImage to indicate a successful readiness point or to carry additional image-related metadata.

Payloads and timing can vary, but common elements include a reference to the image element (or its data), the source URL, and image characteristics such as naturalWidth and naturalHeight. Some implementations may also provide decoding status, load times, or a translucent placeholder state used for progressive loading.

Because onImage is library-specific, developers should consult the documentation for the particular framework or component in use. When integrating onImage, it is important to consider browser behavior, proper sequencing with other image-related events, and fallback handling for failed or delayed loads. In some contexts, onImage may be used to trigger further processing (such as drawing to a canvas or applying effects) once the image is guaranteed to be ready. See also onLoad, onError, and the Image element.