Re: excel format: SUPBOOK records

[Urban Widmark <urban svenskatest se>]

On Mon, 13 Dec 1999, Michael Meeks wrote:

> 
> Hi Urban,
> 
> On Tue, 14 Dec 1999, Urban Widmark wrote:
> > In plugins/excel/ms_excel_read_supporting_wb, around line 3426, it says:
> > Is that comment old or is that the current state of gnumeric/excel-plugin
> > knowledge? (on this particular record)
> 
> 	It is fairly recent, and totaly accurate AFAIK. Jody did some work
> on inter-workbook bits I think, but there is probably a good way to go. It

The ms_excel_read_supporting_wb in 0.45 does not parse SUPBOOK records
correctly. The format is

guint16  numTabs
unicode  pathname
unicode  tabNames[numTabs]

where pathname is a normal unicode string where some characters have
special meanings. The first char of the string gives the encoding used
(0 - empty, 1 - encoded, 2 - self). The encoding used for 1 (0 and 2 seem
pointless) uses characters 1-8 for separating filenames and defining
"volumes".

I have a patch that modifies the function to parse this. It's 4k and
doesn't really do much ... I'll send it offlist if you want it.

The old code read part of the length of the pathname string as the
encoding.


> 	Heh, it just needs someone to work on it :-) if you are interested
> we can point you to the code to read etc. Jody is the guy to talk to.

I'm not making any promises about producing anything useful ... but here
is my view of things.

Problems:
---------
1. When reading one excel workbook you must be able to read another, or
   store which other files to read when done with the current 
   (recursively?)
2. If you have a name such as "C:\f00f\my.xls" which file should you read?
3. A formula in one gnumeric book must be able to refer to a cell in
   another gnumeric book (in memory).
4. To be excel-like the supporting workbooks should be invisible (no
   window).
5. more problems?


Thoughts:
---------
1. Unless you need the supbook during the read (I hope not) then it would
   be enough to read the supbook(s) after the main book has been read.
2. Read my.xls from the user specified path (.:/smbfs/server/document/)
   and ignore the given path since it is most likely wrong.
3. ? I'm lost here ...
4. Not very important, but probably not too difficult. Problems 1 and 2
   could be solved by requiring the user to load the supbook manually
   first, but that's not very nice.

3 looks like a rather difficult thing that affects a lot of internal stuff
so any pointers there would be most helpful (it may be a modification to a
CellRef, but not all code dealing with those are going to like ref's to
other books ... or maybe they do, what do I know :)

I also thought about reading the sheets from the supbook and adding those
to the current book (hidden, special no-save tag?). But that gets messy
when loading and saving (the refs to the extra sheets must be modified
from/to external, how do you write back supbook records).


> 	This is Jody's field too, although this may be more difficult than
> rendering in the sheet for various reasons.

Well, who needs borders anyway :)

/Urban