Note that another benefit of option 2 is that we can down the road (post 3.4)
implement a way to pre-select which facet element is enabled (say you want to
filter by Epson and Canon by default for the first query).
facet().name("Brand")
.onField("brand")
.discrete()
.select("Epson", "Canon")
.createFacetRequest();
Same for range, which might be even more useful.
BTW what's the facet.value() for a range facet?
On 14 mars 2011, at 15:29, Emmanuel Bernard wrote:
> As you guys know I've not been comfortable with the idea of reusing Filter as
> an implementation as it seem to be it is an implementation detail that we
> might change down the road and that is of no interest to the user.
>
> Instead of bitching abstractly, I've decided to implement a CDI style bean
> that implement faceted search to see how the API us used.
>
> Note that I have tried to implement what amazon does
> http://www.amazon.com/gp/search/ref=sr_nr_scat_392442011_ln?rh=n%3A392442011%2Ck%3Ascreen&keywords=screen&ie=UTF8&qid=1300105439&scn=392442011&h=9aa8a737035ed82d321ca117e8f48611956411e5#/ref=nb_sb_noss?url=node%3D392442011&field-keywords=screen&rh=n%3A172282%2Cn%3A%21493964%2Cn%3A281407%2Cn%3A172575%2Cn%3A392442011%2Ck%3Ascreen
>
> My feature list was:
> - multiple facets per query
> - ability to select one or more discrete facet values on a given facet (ie
> brand = epson or canon)
> - ability to display the facet menu on the left
> - ability to remember the state of the selected facet values
>
> While implementing it I've found several proposals for enhancement:
> - should we rename in thw facet DSL createFacet to createFacetRequest(), as
> it's the object returned
> - does facet work with pagination (ie is not affected) => we did some
> optimization around QueryHits when paginating => add a unit test
> - jpa.FullTextQuery does not have the facet methods
> - move Facet methods hosted on FTQuery to a FacetManager interface and do
> ftQuery.getFacetManager().enableFacet("cdscds");
> - make FacetRequest / FacetResults interfaces?
> - Facet should implement equals / hashCode or else we cannot remember the
> facet selected
> - //TODO should the index be included in object Facet? Not sure but worth
> thinking about => probably not if Facet objects change indexes from one query
> to the other
> - should we rename Facet to FacetElement? We seem to talk about Facets as the
> global concept whereas Facet the object represent one of the results of the
> Facet.
>
> The client of the service is as followed
> https://gist.github.com/869181
>
> The solution with the current API is as followed
> https://gist.github.com/869143
>
> In this implementation:
> - I need to keep some kind of state besides the query to remember which facet
> has been selected by the user and which one have not been.
> - I need to remember this state across query re execution: even if the
> request (and thus the facetREsults) are updated, I need to remember this
> state or the user will yell
> - FacetFilter as it is does not solve the problem at had as I need to:
> . use a OR filter for selected elements across a Facet
> . use AndFilter to aggregate the various facets and filter the results
> across all of them
> - I ended up writing and manipulating various OrFacetFilter and AndFilter
> object which are not exactly easy to play with
>
> I've worked on an alternative API that internalize the management of this
> facet element selection so that the whole filter tree can be managed by
> Hibernate Search itself and exposed to the user as a service
>
> https://gist.github.com/869145
>
> Query execution and faceting display are of similar complexity. But the
> select or deselect method is simpler. Also note that I no longer need to
> implement or manipulate And/Or filters myself (and potentially forget to set
> it).
> I have attached the state of the selected facet elements on the FacetRequest
> (the FacetResults are destroyed and reset upon requery). We might want to
> move it up to FacetManager (not shown here), I ahve not thought about it.
>
> What do you guys think? If I had to write a book on Hibernate Search, I'd
> prefer the second option by a big margin.
>
> On 11 mars 2011, at 20:08, Hardy Ferentschik wrote:
>
>> Hi,
>>
>> sorry for the following lengthy code example, but it is hard to
>> demonstrate this much shorter.
>> The example shows how you can enable multiple facets and then continuously
>> restrict the query result
>> by chaining facets into a FacetFilter (which delegates to a ChainedFilter
>> underneath). WDYT?
>> If you want to see all the code or even get the feature branch -
>> https://github.com/hferentschik/hibernate-search/blob/HSEARCH-706
>>
>>
>> public void testMultipleFacetDrillDown() throws Exception {
>> final String ccsFacetName = "ccs";
>> final String ccsFacetFieldName = "cubicCapacity";
>> FacetRequest ccsFacetRequest = queryBuilder( Car.class ).facet()
>> .name( ccsFacetName )
>> .onField( ccsFacetFieldName )
>> .discrete()
>> .createFacet();
>>
>> final String colorFacetName = "color";
>> final String colorFacetFieldName = "color";
>> FacetRequest colorFacetRequest = queryBuilder( Car.class
>> ).facet()
>> .name( colorFacetName )
>> .onField( colorFacetFieldName )
>> .discrete()
>> .createFacet();
>>
>> FullTextQuery query = createMatchAllQuery( Car.class );
>> query.enableFacet( colorFacetRequest );
>> query.enableFacet( ccsFacetRequest );
>> assertEquals( "Wrong number of query matches", 50,
>> query.getResultSize()
>> );
>>
>> List<Facet> colorFacetList = getFacetListForFacet( query,
>> colorFacetName
>> );
>> assertFacetCounts( colorFacetList, new int[] { 12, 12, 12, 12,
>> 2 } );
>>
>> List<Facet> ccsFacetList = getFacetListForFacet( query,
>> ccsFacetName );
>> assertFacetCounts( ccsFacetList, new int[] { 17, 16, 16, 1 } );
>>
>> FacetFilter facetFilter = new FacetFilter();
>> query.setFilter( facetFilter );
>>
>> facetFilter.addFacet( colorFacetList.get( 0 ) );
>> colorFacetList = getFacetListForFacet( query, colorFacetName );
>> assertFacetCounts( colorFacetList, new int[] { 12, 0, 0, 0, 0 }
>> );
>>
>> ccsFacetList = getFacetListForFacet( query, ccsFacetName );
>> assertFacetCounts( ccsFacetList, new int[] { 4, 4, 4, 0 } );
>>
>> facetFilter.addFacet( ccsFacetList.get( 0 ) );
>> // needs to set the filter explicitly atm, because I need the
>> query
>> state to reset
>> query.setFilter( facetFilter );
>> colorFacetList = getFacetListForFacet( query, colorFacetName );
>> assertFacetCounts( colorFacetList, new int[] { 4, 0, 0, 0, 0 }
>> );
>>
>> ccsFacetList = getFacetListForFacet( query, ccsFacetName );
>> assertFacetCounts( ccsFacetList, new int[] { 4, 0, 0, 0 } );
>> }
>>
>> I like the idea of using Lucene Filters to implement the drilldown for. It
>> seems the most natural and the original query stays
>> untouched.
>>
>> --Hardy
>>
>> _______________________________________________
>> hibernate-dev mailing list
>> hibernate-dev@lists.jboss.org
>> https://lists.jboss.org/mailman/listinfo/hibernate-dev
>
>
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