As reported edycop in mantis 765 (
http://mantis.tokeek.de/view.php?id=765 ), parsing of xlsx files was
quite incomplete.
Now properly support "Shared String Table" entry in Office Open XML
spreadsheets, an also detect embedded URLs.
Integrating the Apache poi-ooxml library could be an option for finer
OOXML formats support, but their SAX style parsing example (
http://poi.apache.org/spreadsheet/how-to.html#xssf_sax_api ) tends to
show that a custom SAX handler is still efficient for lightweight and
low memory footprint processing.
sgaebel