For a unique and interesting browsing experience, try using Opera 9.62 to explore the nuances of cross-sub-domain JavaScript calls with Ajax. To understand this better, follow these instructions by placing three simple files on appropriate domains.
foo.html (parent of boo.html iframe) at foo.example.com
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="content-type" content="text/html; charset=utf-8" />
<title>foo</title>
<script type='text/javascript'>
document.domain = 'example.com';
function sendRequest() {
window.frames['boo'].sendRequest();
}
</script>
<head>
<body>
<input type="submit" value="sendRequest" onclick="sendRequest();" />
<iframe name="boo" src="http://boo.example.com/boo.html"></iframe>
</body>
</html>
boo.html (iframe of foo.html) at boo.example.com
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="content-type" content="text/html; charset=utf-8" />
<title>boo</title>
<script type='text/javascript'>
document.domain = 'example.com';
function sendRequest() {
var request = null;
if (window.XMLHttpRequest) {
request = new XMLHttpRequest();
} else {
request = new ActiveXObject('Microsoft.XMLHTTP');
}
if (request) {
request.open('GET', 'http://boo.example.com/helloworld.php', true);
request.onreadystatechange = function() {
if (request.readyState == 4) {
var result = request.responseText;
alert(result);
}
}
request.send('');
}
}
</script>
<head>
<body>
</body>
</html>
helloworld.php at boo.example.com
<?php
echo 'Hello World!';
?>
If you run the above code in browsers other than Opera 9.62, it will function perfectly (tested in Safari, Firefox, Chrome). However, in Opera, a security violation error occurs. Can anyone shed light on this issue? I have a solution that I will share later (I welcome your input too), but I am also eager to hear different perspectives on this problem.
UPDATE: After testing on the latest Opera 10.63, it appears that this issue no longer persists. Therefore, you must specifically use Opera v9.62 to encounter this challenge.