If you use XHTML as HTML-Standard, which is recommended, to build your sites and you use JavaScript, you could have problems with document.write. Especially third-party JavaScript extensions like GoogleMaps or CKEditor use document.write to easily inject own JavaScript code.
But this is denied by specification for XHTML-Documents delivered with content-type application/xhtml+xml instead of text/html. You will receive the DOM Exception #7 by calling document.write or while using innerHTML (Example in Safari: “Error: NO_MODIFICATION_ALLOWED_ERR: DOM Exception 7”; in Firefox: uncaught exception: [Exception… “Component returned failure code: 0x80004003 (NS_ERROR_INVALID_POINTER) [nsIDOMNSHTMLElement.innerHTML]” nsresult: “0x80004003 (NS_ERROR_INVALID_POINTER)” location: … ]). The solution is to deliver the Website with content-type “text/html” instead of “application/xhtml+xml”.
In SEAM using Facelets (with JSF) as View, you can set the content-type in the f:view-Tag. This would look like:
1 2 3 4 5 | ... <f :view contentType="text/html"> .... </f> ... |