Question

Is there a pre-existing library to extract plain text form Open XML file formats (e.g. docx, pptx, and xlsx) files?

I require this to populate a lucene.net index.

I’ve found this example which extracts text from docx and it seems to work okay. But before building my own solution based on this I was wondering if there’s something already available for the other file formats?

Answer 1

Before spending cash, it may be worth looking at the IFilter interface – these were/are designed to do exactly what you want.

http://msdn.microsoft.com/en-us/library/ms691105

http://www.codeproject.com/KB/cs/IFilter.aspx

(Some links at the bottom of the codeprject link).

MS provide IFilters for office file types.
http://www.microsoft.com/downloads/details.aspx?familyid=60c92a37-719c-4077-b5c6-cac34f4227cc&displaylang=en

I know that we use this technology to allow us to index PDFs using Lucene but I did not write the actual code and cannot be of much use I am afraid.

If your Google-fu is strong I am sure you can dig up more examples of using IFilters to do exactly what you want.