I am investigating possible modifications to the CollapsingQParserPlugin that will allow me to collapse documents based on multiple fields. In a quick test I was able to make this happen with two fields, so I assume I can expand that to N fields.
What I'm missing now is the extra data I need per group - the count of collapsed docs and a summation on one numeric field. With single field collapsing I could get this info from the standard stats component by using tagging/excluding on the post filter and setting a stats facet field. Once there are multiple fields, I lose the "free" stats info since faceting only works with one field. So I'm looking for advice on where/when to collect the extra data, and how to transport it back to the caller. My first thought is to compute the info in the collect() method of the DelegatingCollector, and store it with the filter (somehow) so it can be retrieved in a later custom SearchComponent. But I've read it is NOT a good idea to get a document within the collect() method. What is the right way (place) to access a doc field value (not the ordinal)? I read a post by Joel B. where he said you could get access to a ResponseBuilder directly from a post filter via a static SolrRequestInfo call. Does this mean I could compute the extra data I need in the post filter, AND write it out to the response (from the finish() method I guess)? No need for a custom SearchComponent? I was thinking I would have to follow the ExpandComponent model to get the data from the filter, then write it out in the process() method. This is my first attempt at customizing Solr so I may not be expressing myself clearly. Thank you for any pointers you can provide. (using Solr 4.9) -- View this message in context: http://lucene.472066.n3.nabble.com/How-to-return-custom-collector-info-tp4180502.html Sent from the Solr - User mailing list archive at Nabble.com.
