title: Global JavaScript event for missing resources
body: <p>I wonder if that is possible to handle missing resources of a web page all togather including missin images from <code>background: url(...)</code> from CSS.</p>
  <p>I have checked <code>document.addEventListener(&quot;error&quot;, eventHandler, true);</code>, <code>window.onerror</code> and also <code>performance.getEntries()</code> but none of them reports missing images referenced from CSS even from inlined styles.</p>
  <p>Best base to also handle missing resources from other origins e.g. broken fonts referenced from CDNs.</p>