Version 15 no longer allows copy to clipboard

Question

We have been setting signed.applets.codebase_principal_support in FireFox to allow copying to the clipboard in Window XP and Windows 7. It has worked fine until version 15, and it no longer works. If we cannot use this feature, we will have to convert all of our users to IE or some other browser that allows us to do the copy.

Answer 1

So… of what I can tell so far, it is quite true that Firefox no longer allows scripts to access the clipboard, with the exception of making add-ons in the XUL environment. When I first ran into this problem in version 15 on a page I was running locally, the error returned was
A script from "file://" was denied UniversalXPConnect privileges
in response to the statement '''netscape.security.PrivilegeManager.enablePrivilege('UniversalXPConnect')'''.
Nowadays, you’ll get
TypeError: netscape.security.PrivilegeManager is undefined
I first learned of this method of accessing the clipboard from [https://developer.mozilla.org/en-US/docs/Using_the_Clipboard one of the Mozilla Developer docs]. The article begins: “Mozilla provides a number of interfaces for accessing the clipboard”. I’ve not yet found any information about the other interfaces.
Thanks to Google, I did find a live link for [http://docs.oracle.com/cd/E19957-01/816-6171-10/ Netscape Object Signing: Establishing Trust for Downloaded Software], which [http://www.mozilla.org/projects/security/components/signed-scripts.html Signed Scripts in Mozilla] recommends reading before working with signed scripts. The Signed Scripts article says you should use Mozilla’s signtool, apparently from a suite of programs called [http://www.mozilla.org/projects/security/pki/nss/tools/ NSS tools]. It provides that link to the tools, but the only link for the signtool program is to the source code files that you must compile. The [http://www.mozilla.org/projects/security/pki/nss/tools/ man page] for the program is also at the Mozilla Developer Network. I’ll try to study this material soon and provide a more straightforward guide.
In the meantime, I found [http://forum.maxthon.com/viewthread.php?tid=79469 a forum] that talks about another approach to accessing the clipboard by way of saying '''[https://developer.mozilla.org/en-US/docs/Rich-Text_Editing_in_Mozilla document.designMode = “on”]'''. This makes every element editable, as though every element’s contentEditable property were assigned to true. In fact, both properties came from IE.
In the forum I linked to, there’s a JS example were '''designMode''' is turned on and a [https://developer.mozilla.org/en-US/docs/DOM/range Range] is used to select text. The command '''document.execCommand("copy", false, null)''' is intended to actually copy the text, but if you try this in Firefox, you’ll get
Error: Access to XPConnect service denied
I also tried toggling '''signed.applets.codebase_principal_support''' to '''true''' and restarting Firefox but, unfortunately, the JavaScript console still reports no '''PrivilegeManager''' property underneath '''netscape.security''', and '''document.execCommand''' gives its same error in '''designMode'''.
One popular workaround for allowing Firefox to add text to the clipboard is [http://jonrohan.github.com/ZeroClipboard/ ZeroClipboard], which uses an invisible flash movie. You can associate the movie with any element and it acts as a conduit for an element’s access to the event model. I’ve not used it yet, but the example works.