Examine Facets

Powerful filtering and faceting directly within the Examine fluent API.

This package requires Examine 1.1.0+.

Usage

Examine Facets integrates seamlessly with the Examine API. Read the Examine docs first.

Register the searcher

There are 2 facet engines available out of the box: Bobo Browse and Multi Facets. Both offer a similar choice of features and performance so it is really a matter of preference.

To perform facet queries the chosen facet engine's Searcher must be registered via ExamineManager. This requires only a few lines of configuration code.

if (examineManager.TryGetIndex("CustomIndex", out IIndex index))
{
    if (index is LuceneIndex luceneIndex)
    {
        var searcher = new BoboFacetSearcher(
            "FacetSearcher",
            luceneIndex.GetIndexWriter(),
            luceneIndex.DefaultAnalyzer,
            luceneIndex.FieldValueTypeCollection
        );

        examineManager.AddSearcher(searcher);
    }
}

Querying

Defining and querying facets is baked right into Examine's fluent API.

Begin a facet query by calling .Facet(string field) within a query, or filter results to a facet with a specific value by calling .Facet(string field, string[] values).

Further optional configuration – such as the minimum number of matches required for a facet to appear, or the maximum number of values to return – can also be configured configured through the fluent API.

examineManager.TryGetSearcher("FacetSearcher", out ISearcher searcher);

var query = searcher.CreateQuery();

query.And().Facet("CustomField").MinHits(10).MaxCount(100);

Results

Facet searches behave the same as any other Examine search. To retreive information about facets there are some handy extension methods.

To get a list of all facets: results.GetFacets();

To get a list of values for a specific facet: results.GetFacet(string field);

To get the number of hits for a specific value: results.GetFacet(string field).GetHits(object value);