I tried to look into details of XLSX, so created a tiny spreadsheet in Excel 2007 (size - 9KB zipped)
and opened it in WinZip.
It created a complex file structure with 6 directories and 12 files, mostly XMLs.
I found that it writes data to 2 files: : xl/sharedStrings.xml & xl/worksheets/sheet1.xml
That is a way too complex to figure out & implement without running into a lot of troubles.
So I decided to change approach and switch to using Apache POI framework (XSSF),
with Blaze in between.
Can anybody suggest how to design an AIR app which can read Excel 2007 XLSX file,
get data into a DataGrid, user updates it and saves into XLSX.
Do I need a separate Java Servlet ?
Communicate AIR-servlet via HTTP ? ByteStream ?
I am fairly new to that...