iframe-child-postmessage.html

<!DOCTYPE html>
<html lang="zh-TW">
<head>
<meta charset="utf-8">
<title>iframe child window -postMessage</title>
</head>
<body>

<h1>I am iframe (child)</h1>

<p>1. get parent message</p>
<script>
// 1. 接收 parent button 訊息
window.onmessage = function(e){
    if (e.data == 'test') {
        alert('come from parent postmessage');
    }
};
</script>

<p>2. children send postmessage to parent </p>
<button onclick="parent.postMessage('test-from-children', '*');">send hello to parent(postmessage)</button>

</body>
</html>