Feature to support 'in' clause based on jsonapi filter=1,2,3 - BUG: m…

…iLibris#189

flask_rest_jsonapi/querystring.py

@@ -61,8 +61,17 @@ def _get_key_values(self, name):
         return results
 
     def _simple_filters(self, dict_):
-        return [{"name": key, "op": "eq", "val": value}
-                for (key, value) in dict_.items()]
+        """Return filter list
+
+        :return list: list of dict for filter parameters. Includes support for 'in' for list values
+        """
+        filter_list = []
+        for (key, value) in dict_.items():
+            operator = 'eq'
+            if isinstance(value, list):
+                operator = 'in'
+            filter_list.append({"name": key, "op": operator, "val": value})
+        return filter_list
 
     @property
     def querystring(self):