Mailmerge Field not always saved the same way in Word .docx

Question

I have created a Word document with Word 2003 and inserted some MergeField via the GUI. I have saved it as a .docx by using Microsoft Office Compatibility Pack for Word, Excel, and PowerPoint 2007 File Formats. Some Mergefields are stored as a SimpleField, while others are stored as a FieldCode (with start-FieldChar and end-FieldChar). Some Googling brought me to this blog. As you can see the guy is facing the same problem; but hasn't found a solution yet.

I'm using the following code sample on Codeplex [Fill Mergefields] to replace the MergeFields with the actual values from different datasources.

Any help is welcome.

Answer 1

If a field's value is just simple text with consistent formatting, it can be stored as a fldSimple node. However, if the field's value has varying formatting, it has to be saved as a complex field (fldChar Start, Optional Separate, and End) so that each run within the field's value can have it's different formatting defined in the run properties <w:rPr>. I think that also happens if word uses the rsid attributes to track changes. The fldChar Start/Separate/End are also necessary if the fields are nested, such as multiple IF fields, so that it can store an arbitrary number of <w:r>, <w:p>, <w:tbl> as the field's value.

And sometimes it stores them like that for seemingly no good reason. (As that blog noted).