Accessing CustomXMLPart in document included using INCLUDETEXT field

Question

I have a docx Word document that contains Content Controls bound to data in a CustomXMLPart.

This document (or bookmarks therein) is then included in another Word document by using INCLUDETEXT.

When the first document is included into the second is there any way of getting the CustomXMLPart from the original document (I already have a VSTO Word Addin running in Word looking at the document)?

What I want to do is merge it with the CustomXMLParts already present in the second document so that the Content Controls are still bound to the data in the XMLPart.

Alternatively, is there another way to do this without using the INCLUDETEXT field?

Answer 1

I decided this probably wasn't possible using VSTO and IncludeText fields and investigated using altChunks as an alternative.

I was already doing some processing on the file using the Open XML SDK 2 before opening it so could so the extra work required to merge the document together there.

Although using the altChunk method embeds the whole second document in the first, including its own CustomXmlParts, the CustomXmlParts are discarded by Word when the document is opened and the second merged with the first.

I ended up with code similar to the following. It replaces defined Content Controls with altChunk data and merges specific CustomXmlParts together.

    private static void CreateAltChunksInWordDocument(WordprocessingDocument doc, string externalDocumentPath)
    {
        foreach (var control in doc.ContentControls().ToList()) //Have to do .ToList() on this as when we update the Doc in the loop it stops enumerating otherwise
        {
            SdtProperties props = control.Elements<SdtProperties>().FirstOrDefault();
            if (props == null)
                continue;

            SdtAlias alias = props.Elements<SdtAlias>().FirstOrDefault();
            if (alias == null || !alias.Val.HasValue || alias.Val.Value != "External Template")
                continue;

            using (WordprocessingDocument externaldoc = WordprocessingDocument.Open(externalDocumentPath, false))
            {
                //Replace the Content Control with an AltChunk section, and stream in the external file
                string altChunkId = "AltChunkId" + Guid.NewGuid().ToString().Replace("{", "").Replace("}", "").Replace("-", "");

                AlternativeFormatImportPart chunk = doc.MainDocumentPart.AddAlternativeFormatImportPart(AlternativeFormatImportPartType.WordprocessingML, altChunkId);
                chunk.FeedData(File.OpenRead(externalDocumentPath));

                AltChunk altChunk = new AltChunk();
                altChunk.Id = altChunkId;

                OpenXmlElement parent = control.Parent;
                parent.InsertAfter(altChunk, control);
                control.Remove();

                XDocument xDocMain;
                CustomXmlPart partMain = MyCommon.GetMyXmlPart(doc.MainDocumentPart, out xDocMain);

                XDocument xDocExternal;
                CustomXmlPart partExternal = MyCommon.GetMyXmlPart(externaldoc.MainDocumentPart, out xDocExternal);

                if (xDocMain != null && partMain != null && xDocExternal != null && partExternal != null)
                {
                    MyCommon.MergeXmlPartFields(xDocMain, xDocExternal);

                    //Save the updated part
                    using (Stream outputStream = partMain.GetStream())
                    {
                        using (StreamWriter ts = new StreamWriter(outputStream))
                        {
                            ts.Write(xDocMain.ToString());
                        }
                    }
                }
            }
        }
    }