?_facet_size=100 parameter, closes #1332

docs/facets.rst

@@ -84,6 +84,8 @@ This works for both the HTML interface and the ``.json`` view. When enabled, fac
 
 If Datasette detects that a column is a foreign key, the ``"label"`` property will be automatically derived from the detected label column on the referenced table.
 
+The default number of facet results returned is 30, controlled by the :ref:`setting_default_facet_size` setting. You can increase this on an individual page by adding ``?_facet_size=100`` to the query string, up to a maximum of :ref:`setting_max_returned_rows` (which defaults to 1000).
+
 Facets in metadata.json
 -----------------------
 

docs/json_api.rst

@@ -371,6 +371,12 @@ Special table arguments
     Pagination by continuation token - pass the token that was returned in the
     ``"next"`` property by the previous page.
 
+``?_facet=column``
+    Facet by column. Can be applied multiple times, see :ref:`facets`. Only works on the default JSON output, not on any of the custom shapes.
+
+``?_facet_size=100``
+    Increase the number of facet results returned for each facet.
+
 ``?_trace=1``
     Turns on tracing for this page: SQL queries executed during the request will
     be gathered and included in the response, either in a new ``"_traces"`` key

docs/plugin_hooks.rst

@@ -619,6 +619,7 @@ Each Facet subclass implements a new type of facet operation. The class should l
             # using self.sql and self.params as the starting point
             facet_results = {}
             facets_timed_out = []
+            facet_size = self.get_facet_size()
             # Do some calculations here...
             for column in columns_selected_for_facet:
                 try: