| <!DOCTYPE html> |
| <head> |
| <title>Iframes with loading='lazy' load when in the viewport</title> |
| <link rel="author" title="Scott Little" href="mailto:sclittle@chromium.org"> |
| <link rel="author" title="Dom Farolino" href="mailto:dom@chromium.org"> |
| <link rel="help" href="https://github.com/whatwg/html/pull/5579"> |
| <script src="/resources/testharness.js"></script> |
| <script src="/resources/testharnessreport.js"></script> |
| </head> |
| |
| <script> |
| const t_in_viewport = |
| async_test('In-viewport iframes load eagerly'); |
| const t_below_viewport = |
| async_test('Below-viewport iframes load lazily'); |
| const t_below_viewport_srcdoc = |
| async_test('Below-viewport srcdoc iframes load lazily'); |
| const t_below_viewport_data_url = |
| async_test('Below-viewport data: url iframes load lazily'); |
| const t_below_viewport_blob_url = |
| async_test('Below-viewport blob url iframes load lazily'); |
| |
| |
| document.addEventListener('DOMContentLoaded', e => { |
| const blob_url_iframe = document.querySelector('#below_viewport_blob_url'); |
| const blob = new Blob(['<p>Blob subframe</p>'], {type: 'text/html'}); |
| const url = URL.createObjectURL(blob); |
| blob_url_iframe.src = url; |
| }); |
| |
| let has_window_loaded = false; |
| |
| const in_viewport_iframe_onload = t_in_viewport.step_func_done(() => { |
| assert_false(has_window_loaded, |
| "The in_viewport iframe should not block the load event"); |
| }); |
| |
| window.addEventListener("load", () => { |
| has_window_loaded = true; |
| document.getElementById("below_viewport_srcdoc").scrollIntoView(); |
| }); |
| |
| const below_viewport_iframe_onload = t_below_viewport.step_func_done(() => { |
| assert_true(has_window_loaded, |
| "The window load event should have fired before " + |
| "the below-viewport iframe loads"); |
| }); |
| |
| // Onload handlers for below-viewport srcdoc iframe. |
| // Must make this accessible to the srcdoc iframe's body. |
| window.below_viewport_srcdoc_iframe_subresource_onload = t_below_viewport_srcdoc.step_func(() => { |
| assert_true(has_window_loaded, |
| "The window load event should have fired before " + |
| "the below-viewport srcdoc iframe's subresource loads"); |
| }); |
| |
| const below_viewport_srcdoc_iframe_onload = t_below_viewport_srcdoc.step_func_done(() => { |
| assert_true(has_window_loaded, |
| "The window load event should have fired before " + |
| "the below-viewport srcdoc iframe loads"); |
| }); |
| |
| // Onload handler for below-viewport data url iframe. |
| const below_viewport_data_url_iframe_onload = t_below_viewport_data_url.step_func_done(() => { |
| assert_true(has_window_loaded, |
| "The window load event should have fired before " + |
| "the below-viewport data url iframe loads"); |
| }); |
| |
| // Onload handler for below-viewport blob url iframe. |
| const below_viewport_blob_url_iframe_onload = t_below_viewport_blob_url.step_func_done(() => { |
| assert_true(has_window_loaded, |
| "The window load event should have fired before " + |
| "the below-viewport blob url iframe loads"); |
| }); |
| |
| </script> |
| |
| <body> |
| <iframe id="in_viewport" src="resources/subframe.html?in-viewport" |
| loading="lazy" width="200px" height="100px" |
| onload="in_viewport_iframe_onload();"></iframe> |
| |
| <div style="height:2000vh;"></div> |
| <iframe id="below_viewport" src="resources/subframe.html?below-viewport" |
| loading="lazy" width="200px" height="100px" |
| onload="below_viewport_iframe_onload();"></iframe> |
| <iframe id="below_viewport_srcdoc" |
| srcdoc="<body><img src='/common/square.png?below-viewport' |
| onload='parent.below_viewport_srcdoc_iframe_subresource_onload();'></body>" |
| loading="lazy" width="200px" height="100px" |
| onload="below_viewport_srcdoc_iframe_onload();"></iframe> |
| <iframe id="below_viewport_data_url" |
| src="data:text/html,<p>Subframe</p>" |
| loading="lazy" width="200px" height="100px" |
| onload="below_viewport_data_url_iframe_onload();"></iframe> |
| <!-- This iframe has its `src` set to a blob URL dynamically above --> |
| <iframe id="below_viewport_blob_url" |
| loading="lazy" width="200px" height="100px" |
| onload="below_viewport_blob_url_iframe_onload();"></iframe> |
| |
| |
| |
| <!-- This async script loads very slowly in order to ensure that, if the |
| below_viewport* elements have started loading, it has a chance to finish |
| loading before window load event fires, so that the test will dependably |
| fail in that case instead of potentially passing depending on how long |
| different resource fetches take. --> |
| <script async src="/common/slow.py"></script> |
| </body> |
