No, XInclude support was introduced with XMetaL Author Enterprise / Essential version 6.0.
XML Inclusions (XInclude)
W3C XInclude Version 1.0 (Second Edition) introduces a generic mechanism for merging XML documents (as represented by their information sets) for use by applications that need such a facility. The syntax leverages existing XML constructs - elements, attributes, and URL references.
XMetaL Author provides a DocBook sample intended to demonstrate new features such as Xinclude. This sample is available from the Help > Samples menu in XMetaL Author.
XMetaL does not provide a user interface out-of-the-box for working with XML inclusions as the implementation of this feature needs to be specific to particular document types. However, sample code will be provided that you can copy to integrate into your own XMetaL implementation. This sample code will include the following features:
Show or hide XML inclusions
Right-click in a document to open the file that is included via the XML inclusion
Results Manager processes XML inclusion errors that are then displayed in the Results pane at the bottom of the XMetaL Author user interface. You can access individual errors in the Link Errors pane and address issues one by one.
Note that the "sample code" referred to is the code included with the DocBook sample customization. The current Programmers Guide documents the APIs available that are related to the XInclude support. Not all of these are demonstrated with the DocBook sample. Use them to build a UI that makes sense in the context of your particular schema, your workflow, and for the way that you intend your authors to use XInclude.
