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<!doctype html>
<meta charset="utf-8">
<script>
function getOrCreateID(key) {
if (!localStorage.getItem(key)) {
const newID = +new Date() + "-" + Math.random();
localStorage.setItem(key, newID);
}
return localStorage.getItem(key);
}
window.addEventListener("load", () => {
// if we have an opener, we know that we are loaded inside a cross-site
// iframe (because we opened it ourselves).
if (parent.opener) {
const payload = {
message: "cross-site window iframe loaded",
userID: getOrCreateID("userID"),
}
parent.opener.postMessage(payload, parent.opener.origin);
}
});
window.addEventListener("message", (e) => {
if (e.data.command == "create ID") {
getOrCreateID(e.data.key);
// storage is set, call back to window.
const payload = {
message: "ID created",
userID: localStorage.getItem("userID"),
}
e.source.postMessage(payload, e.source.origin);
}
if (e.data.command == "clearStorage") {
localStorage.clear();
}
});
</script>