Merge pull request #86 from alexey-grom/master

Extension point for query formatting at MySQLSearchBackend

src/watson/backends.py

@@ -333,7 +333,7 @@ def escape_mysql_boolean_query(search_text):
         )
         for word in escape_mysql_boolean_query_chars(search_text).split()
     )
-    
+
 
 class MySQLSearchBackend(SearchBackend):
 
@@ -374,17 +374,20 @@ class MySQLSearchBackend(SearchBackend):
     requires_installation = True
     
     supports_ranking = True
+
+    def _format_query(self, search_text):
+        return escape_mysql_boolean_query(search_text)
     
     def do_search(self, engine_slug, queryset, search_text):
         """Performs the full text search."""
         return queryset.extra(
             where = ("MATCH (title, description, content) AGAINST (%s IN BOOLEAN MODE)",),
-            params = (escape_mysql_boolean_query(search_text),),
+            params = (self._format_query(search_text),),
         )
         
     def do_search_ranking(self, engine_slug, queryset, search_text):
         """Performs full text ranking."""
-        search_text = escape_mysql_boolean_query(search_text)
+        search_text = self._format_query(search_text)
         return queryset.extra(
             select = {
                 "watson_rank": """
@@ -418,12 +421,12 @@ class MySQLSearchBackend(SearchBackend):
                 ),
                 "watson_searchentry.content_type_id = %s",
             ),
-            params = (engine_slug, escape_mysql_boolean_query(search_text), content_type.id),
+            params = (engine_slug, self._format_query(search_text), content_type.id),
         )
         
     def do_filter_ranking(self, engine_slug, queryset, search_text):
         """Performs the full text ranking."""
-        search_text = escape_mysql_boolean_query(search_text)
+        search_text = self._format_query(search_text)
         return queryset.extra(
             select = {
                 "watson_rank": """

src/watson/registration.py

@@ -264,7 +264,7 @@ class SearchContext(object):
     def __init__(self, context_manager):
         """Initializes the search index context."""
         self._context_manager = context_manager
-    
+
     def __enter__(self):
         """Enters a block of search index management."""
         self._context_manager.start()
@@ -578,15 +578,15 @@ default_search_engine = SearchEngine("default")
 
 
 # The cache for the initialized backend.
-_backend_cache = None
+_backends_cache = {}
 
 
 def get_backend(backend_name=None):
     """Initializes and returns the search backend."""
-    global _backend_cache
+    global _backends_cache
     # Try to use the cached backend.
-    if _backend_cache is not None:
-        return _backend_cache
+    if backend_name in _backends_cache:
+        return _backends_cache[backend_name]
     # Load the backend class.
     if not backend_name:
         backend_name = getattr(settings, "WATSON_BACKEND", "watson.backends.AdaptiveSearchBackend")
@@ -601,5 +601,5 @@ def get_backend(backend_name=None):
         ))
     # Initialize the backend.
     backend = backend_cls()
-    _backend_cache = backend
+    _backends_cache[backend_name] = backend
     return backend