marc_exporter should have an option to filter out existing 852s

[Rogan Hamby]

when using marc exporter with holdings existing 852s can create added noise at best and at worst create bad data. patch incoming.

[Jason Stephenson (jstephenson)]

We've had to implement a custom export that removes 852s and replaces them with those representing a certain library's holdings for a particular vendor product.

At one point, CWMARS started to add options to marc_export that could be used to remove certain fields and/or fields with matching subfields. It never got very far because it turned into a mini programming language for the command line and other priorities took precedence. See bug 1754455.

[Rogan Hamby (rogan-hamby)]

https://git.evergreen-ils.org/?p=working/Evergreen.git;a=commit;h=9e26157a2a5120ecea0ce9cf11d6812aaece0c6d

[Galen Charlton (gmc)]

To suggest a couple small alternatives:

- just unconditionally removing legacy 852s when the --items switch is in effect.
- adding a --remove-fields option that accepts a list of tags to remove (done, of course, before any 852s are added for items)

Thoughts?

[Jason Stephenson (jstephenson)]

There's a commit from Dan Peal from four years ago that basically does this with regular expressions:

https://git.evergreen-ils.org/?p=working/Evergreen.git;a=commit;h=757309830b8182794b986ca30ab851d389403360

It's from bug 1754455 that I mentioned in my previous comment. I was testing it, but other things came up and I never got back to looking at it.

I misspoke about it becoming a mini-language. Just looking at the commit message and perusing the diff, I think it should work and be useful with a little clean up.

[Jason Stephenson (jstephenson)]

I pushed a cleaned up, rebased version of Dan Pearl's code if anyone wants to have a look:

https://git.evergreen-ils.org/?p=working/Evergreen.git;a=shortlog;h=refs/heads/collab/dyrcona/LP1754455_marc_export_regex

[Jason Boyer (jboyer)]

Since I've already posted my reply intended for this on bug 1754455 I'll mark this one a dupe.