This adds the XMLHttpRequest::open(String, String, bool, String, String)
overload.
The following FIXMEs has been implemented:
- If method is not a method, then throw a "SyntaxError" DOMException.
- If the username argument is not null, set the username given parsedURL
and username.
- If the password argument is not null, set the password given parsedURL
and password.
- Set this’s synchronous flag if async is false; otherwise unset this’s
synchronous flag.
Spec comments has also been updated.
This allows you to ignore the Content-Type returned by the server and
always parse the content as if it's the given MIME type.
This will currently be used for allowing you to override the charset
of text responses.
