What is crossdomain.xml file?

Question

Actually I wish I knew where to start from...

I have embedded an third party SWF image gallery control, in an personal website of mine.

The SWF is XML driven. I load the XML file on the fly as follows....

  var flashvars = { xmlPath: "http://www.example.com/xml.aspx" };
                var params = { allowFullScreen: "true", wmode: "transparent", allowScriptAccess: "always"};
                var attributes = {};
                swfobject.embedSWF("main.swf", "gallery", "100%", "100%", "9.0.0", "expressInstall.swf", flashvars, params, attributes);

The problem is that the page did not work as expected. Actually it worked only in Firefox, not in Chrome or I.E.

After checking the requests with fiddler, i found that the file crossdomain.xml was not found. So, stackoverflow helped me finding a sample...

<?xml version="1.0" ?>
<cross-domain-policy>
  <site-control permitted-cross-domain-policies="master-only"/>
  <allow-access-from domain="*"/>
  <allow-http-request-headers-from domain="*" headers="*"/>
</cross-domain-policy>

After adding the crossdomain.xml the webpage now works in Firefox AND I.E. In Chrome i still have a problem.

So here are a couple of questions...

1) What is the crossdomain.xml?

2) How can i make my webpage work in Chrome too?

Answer 1

"A cross-domain policy file is an XML document that grants a web client—such as Adobe Flash Player, Adobe Reader, etc.—permission to handle data across multiple domains.". Taken from Adobe website http://www.adobe.com/devnet/articles/crossdomain_policy_file_spec.html.

EDIT: Answer to question 2: Flex crossdomain.xml not working correctly in Chrome/Firefox?. Install Adobe Flash Player for developers, Fiddler (or similar), these tools should make your life easier. Also read http://kb2.adobe.com/cps/839/cpsid_83950.html.