Implemented a RangeFacet for FacetedSearch

Closes elastic#199

Author: honzakral

elasticsearch_dsl/faceted_search.py

@@ -8,7 +8,7 @@
 from .utils import AttrDict
 from .result import Response
 
-__all__ = ['FacetedSearch', 'HistogramFacet', 'TermsFacet', 'DateHistogramFacet']
+__all__ = ['FacetedSearch', 'HistogramFacet', 'TermsFacet', 'DateHistogramFacet', 'RangeFacet']
 
 class Facet(object):
     """
@@ -82,13 +82,41 @@ class TermsFacet(Facet):
 
     def add_filter(self, filter_values):
         """ Create a terms filter instead of bool containing term filters.  """
-
         self.filter_values = filter_values
-
         if filter_values:
             return F('terms', **{self._params['field']: filter_values})
 
 
+class RangeFacet(Facet):
+    agg_type = 'range'
+
+    def _range_to_dict(self, range):
+        key, range = range
+        out = {'key': key}
+        if range[0] is not None:
+            out['from'] = range[0]
+        if range[1] is not None:
+            out['to'] = range[1]
+        return out
+
+    def __init__(self, ranges, **kwargs):
+        super(RangeFacet, self).__init__(**kwargs)
+        self._params['ranges'] = list(map(self._range_to_dict, ranges))
+        self._params['keyed'] = False
+        self._ranges = dict(ranges)
+
+    def get_value_filter(self, filter_value):
+        f, t = self._ranges[filter_value]
+        limits = {}
+        if f is not None:
+            limits['from'] = f
+        if t is not None:
+            limits['to'] = t
+
+        return F('range', **{
+            self._params['field']: limits
+        })
+
 class HistogramFacet(Facet):
     agg_type = 'histogram'
 

test_elasticsearch_dsl/test_integration/test_faceted_search.py

@@ -1,6 +1,6 @@
 from datetime import datetime
 
-from elasticsearch_dsl.faceted_search import FacetedSearch, TermsFacet, DateHistogramFacet
+from elasticsearch_dsl.faceted_search import FacetedSearch, TermsFacet, DateHistogramFacet, RangeFacet
 
 class CommitSearch(FacetedSearch):
     doc_types = ['commits']
@@ -9,6 +9,7 @@ class CommitSearch(FacetedSearch):
     facets = {
         'files': TermsFacet(field='files'),
         'frequency': DateHistogramFacet(field='authored_date', interval="day"),
+        'deletions': RangeFacet(field='stats.deletions', ranges=[('ok', (None, 1)), ('good', (1, 5)), ('better', (5, None))])
     }
 
 
@@ -51,7 +52,13 @@ def test_empty_search_finds_everything(data_client):
         (datetime(2014, 5, 2, 0, 0), 1, False)
      ] == r.facets.frequency
 
-def test_filters_are_shown_as_selected_and_data_is_filtered(data_client):
+    assert [
+        ('ok', 19, False),
+        ('good', 14, False),
+        ('better', 19, False)
+    ] == r.facets.deletions
+
+def test_term_filters_are_shown_as_selected_and_data_is_filtered(data_client):
     cs = CommitSearch(filters={'files': 'test_elasticsearch_dsl'})
 
     r = cs.execute()
@@ -87,3 +94,16 @@ def test_filters_are_shown_as_selected_and_data_is_filtered(data_client):
         (datetime(2014, 5, 1, 0, 0), 1, False),
         (datetime(2014, 5, 2, 0, 0), 1, False)
     ] == r.facets.frequency
+
+    assert [
+        ('ok', 12, False),
+        ('good', 10, False),
+        ('better', 13, False)
+    ] == r.facets.deletions
+
+def test_range_filters_are_shown_as_selected_and_data_is_filtered(data_client):
+    cs = CommitSearch(filters={'deletions': 'better'})
+
+    r = cs.execute()
+
+    assert 19 == r.hits.total