Added .values() / .values_list() methods, for fetching less data. Tha…

…nks to acdha for the original implementation!

docs/searchquery_api.rst

@@ -43,10 +43,10 @@ different combinations, you should use ``SQ`` objects. Like
 Example::
 
     from haystack.query import SQ
-    
+
     # We want "title: Foo AND (tags:bar OR tags:moof)"
     sqs = SearchQuerySet().filter(title='Foo').filter(SQ(tags='bar') | SQ(tags='moof'))
-    
+
     # To clean user-provided data:
     sqs = SearchQuerySet()
     clean_query = sqs.query.clean(user_query)
@@ -109,24 +109,26 @@ A basic (override-able) implementation is provided.
 ``run``
 ~~~~~~~
 
-.. method:: SearchQuery.run(self, spelling_query=None)
+.. method:: SearchQuery.run(self, spelling_query=None, **kwargs)
 
 Builds and executes the query. Returns a list of search results.
 
 Optionally passes along an alternate query for spelling suggestions.
 
+Optionally passes along more kwargs for controlling the search query.
+
 ``run_mlt``
 ~~~~~~~~~~~
 
-.. method:: SearchQuery.run_mlt(self)
+.. method:: SearchQuery.run_mlt(self, **kwargs)
 
 Executes the More Like This. Returns a list of search results similar
 to the provided document (and optionally query).
 
 ``run_raw``
 ~~~~~~~~~~~
 
-.. method:: SearchQuery.run_raw(self)
+.. method:: SearchQuery.run_raw(self, **kwargs)
 
 Executes a raw query. Returns a list of search results.
 
@@ -143,7 +145,7 @@ the results.
 ``get_results``
 ~~~~~~~~~~~~~~~
 
-.. method:: SearchQuery.get_results(self)
+.. method:: SearchQuery.get_results(self, **kwargs)
 
 Returns the results received from the backend.
 

docs/searchqueryset_api.rst

@@ -611,6 +611,50 @@ Example::
     suggestion = SearchQuerySet().spelling_suggestion('moar exmples')
     suggestion # u'more examples'
 
+``values``
+~~~~~~~~~~
+
+.. method:: SearchQuerySet.values(self, *fields)
+
+Returns a list of dictionaries, each containing the key/value pairs for the
+result, exactly like Django's ``ValuesQuerySet``.
+
+This method causes the query to evaluate and run the search if it hasn't already
+run.
+
+You must provide a list of one or more fields as arguments. These fields will
+be the ones included in the individual results.
+
+Example::
+
+    sqs = SearchQuerySet().auto_query('banana').values('title', 'description')
+
+
+``values_list``
+~~~~~~~~~~~~~~~
+
+.. method:: SearchQuerySet.values_list(self, *fields, **kwargs)
+
+Returns a list of field values as tuples, exactly like Django's
+``ValuesListQuerySet``.
+
+This method causes the query to evaluate and run the search if it hasn't already
+run.
+
+You must provide a list of one or more fields as arguments. These fields will
+be the ones included in the individual results.
+
+You may optionally also provide a ``flat=True`` kwarg, which in the case of a
+single field being provided, will return a flat list of that field rather than
+a list of tuples.
+
+Example::
+
+    sqs = SearchQuerySet().auto_query('banana').values_list('title', 'description')
+
+    # ...or just the titles as a flat list...
+    sqs = SearchQuerySet().auto_query('banana').values_list('title', flat=True)
+
 
 .. _field-lookups:
 

haystack/backends/__init__.py

@@ -292,6 +292,11 @@ def __init__(self, using=DEFAULT_ALIAS):
         self.date_facets = {}
         self.query_facets = []
         self.narrow_queries = set()
+        #: If defined, fields should be a list of field names - no other values
+        #: will be retrieved so the caller must be careful to include django_ct
+        #: and django_id when using code which expects those to be included in
+        #: the results
+        self.fields = []
         self._raw_query = None
         self._raw_query_params = {}
         self._more_like_this = False
@@ -361,42 +366,54 @@ def build_params(self, spelling_query=None):
         if self.result_class:
             kwargs['result_class'] = self.result_class
 
+        if self.fields:
+            kwargs['fields'] = self.fields
+
         return kwargs
 
-    def run(self, spelling_query=None):
+    def run(self, spelling_query=None, **kwargs):
         """Builds and executes the query. Returns a list of search results."""
         final_query = self.build_query()
-        kwargs = self.build_params(spelling_query=spelling_query)
+        search_kwargs = self.build_params(spelling_query=spelling_query)
+
+        if kwargs:
+            search_kwargs.update(kwargs)
 
-        results = self.backend.search(final_query, **kwargs)
+        results = self.backend.search(final_query, **search_kwargs)
         self._results = results.get('results', [])
         self._hit_count = results.get('hits', 0)
         self._facet_counts = self.post_process_facets(results)
         self._spelling_suggestion = results.get('spelling_suggestion', None)
 
-    def run_mlt(self):
+    def run_mlt(self, **kwargs):
         """
         Executes the More Like This. Returns a list of search results similar
         to the provided document (and optionally query).
         """
         if self._more_like_this is False or self._mlt_instance is None:
             raise MoreLikeThisError("No instance was provided to determine 'More Like This' results.")
 
-        kwargs = {
+        search_kwargs = {
             'result_class': self.result_class,
         }
 
+        if kwargs:
+            search_kwargs.update(kwargs)
+
         additional_query_string = self.build_query()
-        results = self.backend.more_like_this(self._mlt_instance, additional_query_string, **kwargs)
+        results = self.backend.more_like_this(self._mlt_instance, additional_query_string, **search_kwargs)
         self._results = results.get('results', [])
         self._hit_count = results.get('hits', 0)
 
-    def run_raw(self):
+    def run_raw(self, **kwargs):
         """Executes a raw query. Returns a list of search results."""
-        kwargs = self.build_params()
-        kwargs.update(self._raw_query_params)
+        search_kwargs = self.build_params()
+        search_kwargs.update(self._raw_query_params)
 
-        results = self.backend.search(self._raw_query, **kwargs)
+        if kwargs:
+            search_kwargs.update(kwargs)
+
+        results = self.backend.search(self._raw_query, **search_kwargs)
         self._results = results.get('results', [])
         self._hit_count = results.get('hits', 0)
         self._facet_counts = results.get('facets', {})
@@ -426,7 +443,7 @@ def get_count(self):
 
         return self._hit_count
 
-    def get_results(self):
+    def get_results(self, **kwargs):
         """
         Returns the results received from the backend.
 
@@ -436,12 +453,12 @@ def get_results(self):
         if self._results is None:
             if self._more_like_this:
                 # Special case for MLT.
-                self.run_mlt()
+                self.run_mlt(**kwargs)
             elif self._raw_query:
                 # Special case for raw queries.
-                self.run_raw()
+                self.run_raw(**kwargs)
             else:
-                self.run()
+                self.run(**kwargs)
 
         return self._results
 

haystack/backends/solr_backend.py

@@ -1,5 +1,4 @@
 import logging
-import sys
 from django.conf import settings
 from django.core.exceptions import ImproperlyConfigured
 from django.db.models.loading import get_model
@@ -120,6 +119,9 @@ def search(self, query_string, sort_by=None, start_offset=0, end_offset=None,
         }
 
         if fields:
+            if isinstance(fields, (list, set)):
+                fields = " ".join(fields)
+
             kwargs['fl'] = fields
 
         if sort_by is not None:
@@ -459,10 +461,10 @@ def build_query_fragment(self, field, filter_type, value):
 
         return result
 
-    def run(self, spelling_query=None):
+    def run(self, spelling_query=None, **kwargs):
         """Builds and executes the query. Returns a list of search results."""
         final_query = self.build_query()
-        kwargs = {
+        search_kwargs = {
             'start_offset': self.start_offset,
             'result_class': self.result_class,
         }
@@ -476,50 +478,53 @@ def run(self, spelling_query=None):
                 else:
                     order_by_list.append('%s asc' % order_by)
 
-            kwargs['sort_by'] = ", ".join(order_by_list)
+            search_kwargs['sort_by'] = ", ".join(order_by_list)
 
         if self.end_offset is not None:
-            kwargs['end_offset'] = self.end_offset
+            search_kwargs['end_offset'] = self.end_offset
 
         if self.highlight:
-            kwargs['highlight'] = self.highlight
+            search_kwargs['highlight'] = self.highlight
 
         if self.facets:
-            kwargs['facets'] = list(self.facets)
+            search_kwargs['facets'] = list(self.facets)
 
         if self.date_facets:
-            kwargs['date_facets'] = self.date_facets
+            search_kwargs['date_facets'] = self.date_facets
 
         if self.query_facets:
-            kwargs['query_facets'] = self.query_facets
+            search_kwargs['query_facets'] = self.query_facets
 
         if self.narrow_queries:
-            kwargs['narrow_queries'] = self.narrow_queries
+            search_kwargs['narrow_queries'] = self.narrow_queries
+
+        if self.fields:
+            search_kwargs['fields'] = self.fields
 
         if spelling_query:
-            kwargs['spelling_query'] = spelling_query
+            search_kwargs['spelling_query'] = spelling_query
 
-        results = self.backend.search(final_query, **kwargs)
+        results = self.backend.search(final_query, **search_kwargs)
         self._results = results.get('results', [])
         self._hit_count = results.get('hits', 0)
         self._facet_counts = self.post_process_facets(results)
         self._spelling_suggestion = results.get('spelling_suggestion', None)
 
-    def run_mlt(self):
+    def run_mlt(self, **kwargs):
         """Builds and executes the query. Returns a list of search results."""
         if self._more_like_this is False or self._mlt_instance is None:
             raise MoreLikeThisError("No instance was provided to determine 'More Like This' results.")
 
         additional_query_string = self.build_query()
-        kwargs = {
+        search_kwargs = {
             'start_offset': self.start_offset,
             'result_class': self.result_class,
         }
 
         if self.end_offset is not None:
-            kwargs['end_offset'] = self.end_offset - self.start_offset
+            search_kwargs['end_offset'] = self.end_offset - self.start_offset
 
-        results = self.backend.more_like_this(self._mlt_instance, additional_query_string, **kwargs)
+        results = self.backend.more_like_this(self._mlt_instance, additional_query_string, **search_kwargs)
         self._results = results.get('results', [])
         self._hit_count = results.get('hits', 0)