<html>
<script>
var imageLoadResult = 'N/A';
var iframeLoadResult = 'N/A';
function imageLoaded() {
var image = document.getElementById('denylist_image');
// Additional sanity check to make sure the image is indeed loaded.
// Not strictly needed.
if (image.height == 1 && image.width == 1) {
imageLoadResult = "success";
} else {
imageLoadResult = "error";
}
}
function imageError() {
imageLoadResult = "error";
}
function iframeLoaded() {
// Unfortunately, iframe load errors generally don't result in onerror
// actually being called, so also check that the title is accessible.
// Since this is a same-site iframe, it generally should be, unless there's
// an error page showing in the iframe, in which case it's treated as a
// cross-domain iframe.
try {
document.getElementById('denylist_iframe').contentDocument.title;
iframeLoadResult = "success";
} catch (err) {
iframeLoadResult = "error";
}
}
function iframeError() {
iframeLoadResult = "error";
}
</script>
<img id="denylist_image" src="pixel.png" onload="imageLoaded()" onerror="imageError()"></img>
<iframe id="denylist_iframe" src="blank.html" onload="iframeLoaded()" onerror="iframeError()"></iframe>
</html>