| <!DOCTYPE html> | |
| <body> | |
| <script> | |
| var portal = document.createElement("portal"); | |
| portal.src = "portal-post-message-before-activate-portal.html"; | |
| document.body.appendChild(portal); | |
| portal.onload = () => { | |
| portal.postMessage("message"); | |
| portal.activate(); | |
| } | |
| </script> | |
| </body> |