[OPEN-ILS-DEV] What do we want from MARC Format for Holdings Data?

[David J. Fiander]

I've checked in some basic MFHD code. It's a bit further along than  
Dan's parser, but it's still not good. Basically all it does right now  
is generated a formatted list of the "basic" holdings information for  
display, using the correct captioning information.

As written, the code doesn't do anything with 854/864 "Supplementary  
Material" or 855/865 "Indexes" fields in the MARC records, and it  
would be difficult to support them.

Rather than focusing on the data structures, it would probably be more  
useful to focus on the functionality we need. How do these methods  
sound?

mfhd.format(boolean compressed): return formated holdings statement  
suitable for display, either detailed or compressed.

mfhd.predict(vol, iss, yr, mo, day): return information about issue  
that follows that described by the arguments. The return value does  
not necessarily describe something that we hold (it is predicting the  
next issue). This method may return false to indicate that no  
prediction is possible (for example, the captions and pattern data is  
incomplete or indicates that the serial is completely irregular).

This method will be one of the basic building blocks for the claims  
process.

mfhd.iter(): Iterate through holdings in chronological order,  
returning information about each item held.

All methods will have to take an argument indicating whether we want  
"basic", "supplementary" or "indexes" holdings. Calling a method for a  
type of holding that doesn't apply is not an error: we just don't hold  
any of that (or is it an error?).

QUESTIONS

How common is non-"basic" holdings information in the wild? Do we  
really need to support anything beyond the basic serial holdings?

How essential is it that Evergreen be able to export MFHD formatted  
data?

What else do people need to be able to do, or expect to do?

- David

-- 
David J. Fiander
Library Software Development