One of VuFind®'s most prominent features is faceted search, which allows a result set to be narrowed down based on values displayed in a sidebar.

Notes:

• VuFind® allows for “configuration” of facets in terms of which facets to show and in which order. Just edit facets.ini in your favorite text editor to adjust Solr faceting. If you are not using Solr, most third-party content providers also allow faceting, which can be configured in the appropriate .ini file (e.g. Summon.ini, etc.).

• One helpful way to understand facets is to submit queries to Solr to return faceted results directly in XML: Solr's web-based administration panel can allow you to do this; see also the Solr documentation on faceting. You can also turn on debug mode in config.ini to see exactly which URLs VuFind® is generating for its own queries.

• More details on adding facets (with a particular focus on building them using data in MARC records) can be found on the Adding Facets page.

VuFind® supports hierarchical facets with Solr. The facet values need to be indexed as described in the Solr wiki with each value always ending in a trailing slash. Hierarchical facets are defined in facets.ini (see the SpecialFacets section) and there are also settings that define how they are sorted and displayed.

Below is an example of how a building facet could be indexed when the record belongs to a couple of different libraries:

0/MainLib/
1/MainLib/Adults/
1/MainLib/Reference/
0/BranchLib/
1/BranchLib/Main/

Below is an example of format could be indexed for a record that contains physical copies as well as an online version:

0/Book/
1/Book/Book/
1/Book/eBook/

Some of the topics from this page are also covered in the Configuring Search and Facet Settings video.