Factor _get_extra_args into _get_listing_args and overrideable get_filter_args

flask_admin/model/base.py

@@ -948,19 +948,20 @@ class BaseModelView(BaseView, ActionsMixin):
     def get_empty_list_message(self):
         return gettext('There are no items in the table.')
 
-    # URL generation helper
-    def _get_extra_args(self):
+    def get_filter_args(self):
         """
-            Return arguments from query string.
-        """
-        page = request.args.get('page', 0, type=int)
-        sort = request.args.get('sort', None, type=int)
-        sort_desc = request.args.get('desc', None, type=int)
-        search = request.args.get('search', None)
+            Retrieve and parse filter parameters from the request URL.
             
+            Returns a list of 2-tuples in the format [(idx, value), ...],
+            where idx is the index into the list returned by get_filters().
+            
+            Override this method to provide your own URL filter format.
+        """
         filter_idx_by_label = dict((flt.query_label(), i) for i, flt in enumerate(self._filters))
         # Gather filters
-        if self._filters:
+        if not self._filters:
+            return None
+        
         sfilters = []
 
         for n in request.args:
@@ -989,11 +990,17 @@ class BaseModelView(BaseView, ActionsMixin):
                 if flt.validate(value):
                     sfilters.append((pos, (idx, flt.clean(value))))
 
-            filters = [v[1] for v in sorted(sfilters, key=lambda n: n[0])]
-        else:
-            filters = None
+        return [v[1] for v in sorted(sfilters, key=lambda n: n[0])]
 
-        return page, sort, sort_desc, search, filters
+    def _get_listing_args(self):
+        """
+            Return generic list view arguments from query string.
+        """
+        page = request.args.get('page', 0, type=int)
+        sort = request.args.get('sort', None, type=int)
+        sort_desc = request.args.get('desc', None, type=int)
+        search = request.args.get('search', None)
+        return page, sort, sort_desc, search
 
     def _get_url(self, view=None, page=None, sort=None, sort_desc=None,
                  search=None, filters=None):
@@ -1111,7 +1118,8 @@ class BaseModelView(BaseView, ActionsMixin):
             List view
         """
         # Grab parameters from URL
-        page, sort_idx, sort_desc, search, filters = self._get_extra_args()
+        page, sort_idx, sort_desc, search = self._get_listing_args()
+        filters = self.get_filter_args()
 
         # Map column index to column name
         sort_column = self._get_column_by_idx(sort_idx)