Change the DOCTYPE of an Opened XML Document

The following API:

ro.sync.ecss.extensions.api.AuthorDocumentController.getDoctype()  

allows you to get the DOCTYPE of the current XML file opened in the Author page.

There is also an API method available which would allow you to set the DOCTYPE back to the XML:

ro.sync.ecss.extensions.api.AuthorDocumentController.setDoctype(AuthorDocumentType)  

Here is an example of how this solution would work:

AuthorDocumentType dt = new AuthorDocumentType("article", "testSystemID", "testPublicID",
            "<!DOCTYPE article PUBLIC \"testPublicID\" \"testSystemID\">");
docController.setDoctype(dt); 

Basically you could take the entire content from the existing DOCTYPE,

ro.sync.ecss.extensions.api.AuthorDocumentType.getContent()

modify it to your needs, and create another AuthorDocumentType object with the new content and with the same public, system IDs.