[hibernate-dev] [HSearch] Faceting feedback
hibernate at ferentschik.de
Mon Feb 28 10:13:43 EST 2011
I thought it would be great to get some feedback on my faceting work.
You can see the latest on my Search fork -
Technically I decided to use a simple custom Collector. I abandoned the
idea for using bobo browse, since it did
not really seem to fit our architecture and I am not sure how well
maintained the code is.
Within the custom Collector I am using Lucene's FieldCache to cache and
collect the count values during facting
(as a reminder, faceting for example means that I am searching for all
cars or a certain make, but then also want
to group the matching cars into their cubic capacity. See also -
Using the FieldCache is quite memory costly, but there are other ways to
implement the faceting itself.
At the moment I am mostly interested in the feedback around the public
API. The public classes can be found in
the package org.hibernate.search.query.facet -
The idea is to write a fulltext query as usual and then add/enable a facet:
FacetRequest request = new SimpleFacetRequest( indexFieldName,
FacetSortOrder.COUNT_DESC, false );
TermQuery term = new TermQuery( new Term( "make", "honda" ) );
FullTextQuery query = fullTextSession.createFullTextQuery( term, Car.class
query.enableQueryFacet( "foo", request );
Then you run the query. This will enable the facet collector and after the
query executed you get access to a map
which maps FacetResults to the facet name. Each FacetResult contains a
list of Facets which contain the actually
field values and counts:
Map<String, FacetResult> results = query.getFacetResults();
FacetResult facetResult = results.get( "foo" );
List<Facet> facetList = facetResult.getFacets();
assertEquals( "Wrong facet count for facet ", 100, facetList.get( 0
More actual tests can be found here -
At the moment you are able to facet on simple (string) based values or on
number ranges (eg price ranges 0 - 100, ...). For that I have created
FacetRequest - SimpleFacetRequest and RangeFacetRequest (a
DateRangeFacetRequest might be interesting as well)
Some concrete questions:
* Atm, I am only exposing a programmatic API for creating FacetRequests. I
guess we want to have annotations for this as well, right?
Would we keep the programmatic configuration as a public API?
* I made the FacetRequest classes immutable atm, but this way I have a
multitude of constructors catering for a whole range of parameters
(sort order, include zero counts, ...). Any opinions around immutable
objects vs objects with setters for configuring options after creation.
If course I am interested in any other feedback as well.
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