Thanks Michael, at least I would say that it would be good to state this clearly in Lucene API.
More specifically, both the WeightedSpanTermExtractor#getWeightedSpanTerms and #getWeightedSpanTermsWithScores should reflect this in Javadoc. Because both execute private method extract(Query query, Map<String,WeightedSpanTerm> terms) which checks a specific Query subclasses only. As I pointed out not only custom Query implementations will fall through without any results but also some Lucene built-in Queries (like BoostingQuery) and that is confusing IMHO. Should a ticket be opened? Regards, Lukas On Sat, Sep 10, 2011 at 12:08 AM, Michael Sokolov <soko...@ifactory.com>wrote: > Lukas there really isn't any support for custom Query types in Highlighter, > as you've found. If you inherit from one of the types it does support, or > rewrite your query to one of them, that should work, but the Query class > just doesn't provide enough support for Highlighter to work with in the > general case. There is work in LUCENE-3318 which could eventually help, but > it's a ways away from being committed I think. At least that's my read of > the code. > > -Mike > > > On 9/9/2011 7:53 AM, Lukáš Vlček wrote: > >> Hi, >> >> What is the recommended way to use custom Query implementations with >> Lucene >> (3.3.0) Highlighter framework? >> >> In short, what worries me a bit is the fact >> that WeightedSpanTermExtractor#**extract(Query, Map<String, >> WeightedSpanTerm>) >> accepts a general Query parameter but inside it does a lot of tests >> against >> particular implementations ( ... if query instanceof BooleanQuery then ... >> ) >> with no default option to fall back to. What if I have my own (or >> third-party) implementation of Query? Or even with some Lucene built-in >> Query types (like BoostingQuery) there is a chance that the extract() >> method >> will silently fall through and does not let me know that this particular >> Query implementation is unknown to it. >> >> AFAIK typical use case of Highlighter API can go like this: >> >> Query query = _some_query_instance_; >> QueryScorer scorer = new QueryScorer(query, "field"); // query? or >> query.rewrite() or ... ? >> ... etc ... >> Highlighter highlighter = new Highlighter(scorer); >> ... etc ... >> >> Saying this, I am looking for an advice about how to deal with this >> Highlighter API correctly so that I do not have to check the source code >> of WeightedSpanTermExtractor in advance to learn whether I need to call >> rewrite (or other custom method) on the query object or not. >> >> Regards, >> Lukas >> >> >
