| <!DOCTYPE HTML> |
| <meta charset=utf-8> |
| <title>Element Timing: element attribute returns null when element is disconnected</title> |
| <body> |
| <script src="/resources/testharness.js"></script> |
| <script src="/resources/testharnessreport.js"></script> |
| <script src="resources/element-timing-helpers.js"></script> |
| <script> |
| let beforeRender; |
| let img; |
| async_test(function (t) { |
| if (!window.PerformanceElementTiming) { |
| assert_unreached("PerformanceElementTiming is not implemented"); |
| } |
| const observer = new PerformanceObserver( |
| t.step_func_done(function(entryList) { |
| assert_equals(entryList.getEntries().length, 1); |
| const entry = entryList.getEntries()[0]; |
| const pathname = window.location.origin + '/element-timing/resources/square100.png'; |
| // This method will check that entry.element is |img|. |
| checkElement(entry, pathname, 'my_image', 'my_id', beforeRender, img); |
| |
| img.parentNode.removeChild(img); |
| // After removing image, entry.element should return null. |
| assert_equals(entry.element, null); |
| }) |
| ); |
| observer.observe({entryTypes: ['element']}); |
| // We add the image during onload to be sure that the observer is registered |
| // in time for it to observe the element timing. |
| window.onload = () => { |
| // Add image of width equal to 100 and height equal to 100. |
| img = document.createElement('img'); |
| img.src = 'resources/square100.png'; |
| img.setAttribute('elementtiming', 'my_image'); |
| img.setAttribute('id', 'my_id'); |
| document.body.appendChild(img); |
| beforeRender = performance.now(); |
| }; |
| }, 'Disconnected elements have null as their |element| attribute.'); |
| </script> |
| |
| </body> |
