Here’s another Office 2010 undocumented “feature”.

First a little background regarding required fields in sharepoint:
In Office 2007, in order to attach the Sharepoint properties to a document you had to first Save it into the document library. Word would allow you to save, but the document would remain checked-out to you until you filled in the necessary required properties, and checked it in.

If you were developing a system that automated adding documents to SharePoint, you could not even present the Document Information Panel to the user until the document was already in SharePoint. If the user decided to cancel… you had hanging files.

With Office 2010, Word (and I imagine other apps) will not actually complete the Save operation to a SharePoint Document Library when there are required fields. You get a warning and the document is _not_ placed in SharePoint, but the Fields from the Document Library are attached to your Word document.

In Word, if you want to display the “Save As” dialog box pre-populated to a SharePoint library you do something like this:

dynamic dlg = Application.Dialogs[Word.WdWordDialog.wdDialogFileSaveAs];
dlg.Name = "http://sharepointserver/doclib/filename.docx";
dlg.Show();

This will act the same as the normal “Save As” dialog.

If you want to handle the save process yourself, instead of dlg.Show(), use dlg.Display. This *should* take no action regardless if the user presses Ok or Cancel. If the destination happens to be SharePoint – intsead of doing nothing like it is supposed to – Word happily retreives the Sharepoint properties and attaches them to your document.

In addition to being handy, Word will attach the document properties to Read-Only and Protected files – which is something you cannot do using CustomXMLParts.
And it’s a heck of a lot easier than trying to build and attach them yourself.

While it is undocumented (and therefore subject to change), it is kind of impossible to work around — Word WILL attach the sharepoint properties, so you might as well take advantage of it.

UPDATE 3/20/2012: Unfortunately, I have discovered that this method is unreliable. On one of our user’s machines, the Save As dialog refuses to display the sharepoint folder at all. I don’t know why, but I wouldn’t recommend relying on this.