id,page,ref,title,content,breadcrumbs,references
changelog:v0-28-faceting,changelog,v0-28-faceting,"Faceting improvements, and faceting plugins","Datasette  Facets  provide an intuitive way to quickly summarize and interact with data. Previously the only supported faceting technique was column faceting, but 0.28 introduces two powerful new capabilities: facet-by-JSON-array and the ability to define further facet types using plugins. 
                 Facet by array ( #359 ) is only available if your SQLite installation provides the  json1  extension. Datasette will automatically detect columns that contain JSON arrays of values and offer a faceting interface against those columns - useful for modelling things like tags without needing to break them out into a new table. See  Facet by JSON array  for more. 
                 The new  register_facet_classes()  plugin hook ( #445 ) can be used to register additional custom facet classes. Each facet class should provide two methods:  suggest()  which suggests facet selections that might be appropriate for a provided SQL query, and  facet_results()  which executes a facet operation and returns results. Datasette's own faceting implementations have been refactored to use the same API as these plugins.","[""Changelog"", ""0.28 (2019-05-19)""]","[{""href"": ""https://github.com/simonw/datasette/issues/359"", ""label"": ""#359""}, {""href"": ""https://github.com/simonw/datasette/pull/445"", ""label"": ""#445""}]"