as3xls > Number of sheets always 0

Question

I'm trying to parse a .xlsx file exported from a google docs. Right now I'm not trying to access it online, I'm manually downloading it and copying inside my application.

I've read the tutorial provided online, and this is the code I have right now:

 var contentBA:ByteArray = new ByteArray ();
 var fileToLoad:File = File.applicationDirectory.resolvePath("textLabels.xlsx");        
 var stream:FileStream = new FileStream();
 stream.open(fileToLoad, FileMode.READ);
 stream.readBytes (contentBA, 0, contentBA.length);
 var xls:ExcelFile = new ExcelFile();
 xls.loadFromByteArray(contentBA); 
 trace ("N SHEETS ", xls.sheets.length);

but the number of sheets it's always 0. I tried to change the file and to load the most simple excel ever but it keeps saying 0.

Is it a problem of the ".xlsx" extension? Am I missing something?

Answer 1

AS3XLS was written for the old file format BIFF Office 97 style documents. I've written an XLSX exporter for my work on the AdvancedDataGrid but it's proprietary work so I can't share the code unfortunately. However I can give you some direction. The BIFF format used special codes for encoding things like formatting for cells or formulas, the binary format was seemingly meant to reduce the file size (and perhaps as a form of obfuscation). XLSX instead takes the more open XML approach, creating a BIFF file was complicated and was reverse engineered by the Open Office team before Microsoft ever published the spec for it, the newer XML formats are pretty well documented. Every new office file that ends with the x in it's extension is an archive (just like a zip file, you can open it with any archive tool) with a bunch of XML files inside that define the sheet. I basically took a sample sheet with nothing in it (opened Excel saved a new workbook) then pieced it apart and wrote AS3 classes that corresponded to each of the XML files and each implemented an interface that said it had to have a method to getXMLString() then I wrote a wrapper that would create all the objects and used the container pattern/traversal to build all the XML files needed and used the nochump AS3 zip library to package it together.

A useful tool for inspecting the xlsx or docx or whateverx files can be found here: http://www.microsoft.com/en-us/download/details.aspx?id=5124

If you're on Mac discussion on one here: http://openxmldeveloper.org/discussions/development_tools/f/27/p/1494/7453.aspx

Generally the site above was helpful http://openxmldeveloper.org/

Documentation showing (minimal) examples http://www.ecma-international.org/news/TC45_current_work/Office%20Open%20XML%20Part%203%20-%20Primer.pdf

NoChump's AS3 Zip library http://nochump.com/blog/archives/15

Basically for more advanced features like tables or cell spanning I just attempted the change I wanted to be able to make programmatically in a simple Excel file then compared it against another without that new feature using the first tool linked above and implemented the change in the appropriate AS3 class (the one that corresponds to the XML file that changed).

It took about 2 weeks to get the organization of the classes solid but it's absolutely achievable.

Answer 2

ExcelFile is a class from a custom library and it says that supports Excel 2002-2003. What version of Excel do you use?