questions about BlockJoinParentQParser

[Michael Sokolov]

I'm trying to use BJPQP and ran into a few little gotchas that I'd like 
to share with y'all in case you have any advice.

First I ran into an NPE that probably should be handled better - maybe 
just an exception with a better message.  The framework I'm working in 
makes it slightly annoying to use localParams syntax (I have to bypass 
special-character escaping in the client framework), so I thought I'd 
set defType=parent and pass the "which" as a global parameter, but if 
you try this you get an NPE since the QParser expects "which" to be 
passed in as a local param.  It's probably not really a sane use case 
since you have to use localParams to get your default qparser 
instantiated in that case anyway, so why would you do it?  Still - it 
would be good to report a clearer exception to the user.

Then I got my query working, but results were coming back in a funky 
order.  I realized that the client doc scores were being thrown away -- 
BJPQP is hard-coded to use ScoreMode.None.  So then I went to subclass 
the QParser (and plugin) to override the score mode -- createQuery is 
protected, which would seem to make this convenient to do this, but the 
class itself (BlockJoinParentQParser) is package private.  Then I 
thought I'd just put my class in the same package, but this fails at 
runtime since it's loaded by a different class loader. argh.  I would 
have to copy and fork the whole class to get this working.

I guess that's what I'll do, but this should be easier.  Am I missing 
something?  Is there another way to get a scoring ToParentBlockJoinQuery 
in Solr?

Thanks

-Mike