| <?php |
| header("ACCEPT-CH: DPR, Width, Viewport-Width"); |
| ?> |
| <!DOCTYPE html> |
| <body> |
| <script> |
| var fail = function(num) { |
| return function() { |
| parent.postMessage("fail "+ num, "*"); |
| } |
| }; |
| |
| var success = function() { |
| parent.postMessage("success", "*"); |
| }; |
| |
| var loadRWImage = function() { |
| var img = new Image(); |
| img.src = 'image-checks-for-width.php'; |
| img.sizes = '500'; |
| img.onload = success |
| img.onerror = fail(3); |
| document.body.appendChild(img); |
| }; |
| var loadViewportImage = function() { |
| var img = new Image(); |
| img.src = 'image-checks-for-viewport-width.php'; |
| img.onload = loadRWImage; |
| img.onerror = fail(2); |
| document.body.appendChild(img); |
| }; |
| var img = new Image(); |
| img.src = 'image-checks-for-dpr.php'; |
| img.onload = loadViewportImage; |
| img.onerror = fail(1); |
| document.body.appendChild(img); |
| </script> |
| </body> |
