I\'m considering replacing a (very) large body of Office-automation code with something that works with the Office XML format directly. I\'m just starting out, but already I\'m
Having worked with the Open XML SDK 2.0 for almost two years now I can say that doing seemingly trivial tasks can take many hours and sometimes days to figure out how to do it properly. For example, deleting an Excel row should be fairly straightforward and easy to do right? Nope because not only do you need code to delete your row, but then you have to update all the row indices, update any merged cell references, update hyperlink references, etc. Our internal delete method is close to 500 lines of code to just delete a row and I'm sure we don't have all the cases accounted for either.
The biggest complaint I have is the lack of documentation on how to do the most common tasks. The MSDN section on the Open XML SDK is very limited and whenever you need to do anything complicated you are really on your own. I've had to read the Open XML standard a lot to figure out what certain elements mean and how they should be implemented since I could find very little online.
The other challenging part is if you insert an element in a spot where it doesn't belong or put an invalid attribute on an element you will get a corrupt file when you try and open it. Most of the time you will not get any information on what caused the error and you will have to look at the Open XML standard spec to see what you did wrong.
If you need a fast turnaround time on converting that Office automation code into Open XML and what you are doing is not really basic, then I would say pass. If you have time and the patience to read up on the Word, Excel and PowerPoint XML structures and get familiar with how they relate then I say go for it. In my opinion it is really the only way to have very fine control over these office documents, but there will be a great learning curve when you start.
Oh and just for fun here is how much code is needed to add a comment to an Excel cell.