Database independent design

Author: multimeric

flask_rest_jsonapi/data_layers/alchemy.py

@@ -99,17 +99,21 @@ def get_object(self, view_kwargs, qs=None):
 
         return obj
 
-    def get_collection(self, qs, view_kwargs):
+    def get_collection(self, qs, view_kwargs, filters=None):
         """Retrieve a collection of objects through sqlalchemy
 
         :param QueryStringManager qs: a querystring manager to retrieve information from url
         :param dict view_kwargs: kwargs from the resource view
+        :param dict filters: A dictionary of key/value filters to apply to the eventual query
         :return tuple: the number of object and the list of objects
         """
         self.before_get_collection(qs, view_kwargs)
 
         query = self.query(view_kwargs)
 
+        if filters:
+            query = query.filter_by(**filters)
+
         if qs.filters:
             query = self.filter_query(query, qs.filters, self.model)
 

flask_rest_jsonapi/data_layers/base.py

@@ -60,11 +60,12 @@ def get_object(self, view_kwargs):
         """
         raise NotImplementedError
 
-    def get_collection(self, qs, view_kwargs):
+    def get_collection(self, qs, view_kwargs, filters=None):
         """Retrieve a collection of objects
 
         :param QueryStringManager qs: a querystring manager to retrieve information from url
         :param dict view_kwargs: kwargs from the resource view
+        :param dict filters: A dictionary of key/value filters to apply to the eventual query
         :return tuple: the number of object and the list of objects
         """
         raise NotImplementedError

flask_rest_jsonapi/resource.py

@@ -21,6 +21,7 @@
 from flask_rest_jsonapi.data_layers.base import BaseDataLayer
 from flask_rest_jsonapi.data_layers.alchemy import SqlalchemyDataLayer
 from flask_rest_jsonapi.utils import JSONEncoder
+from marshmallow_jsonapi.fields import BaseRelationship
 
 
 class ResourceMeta(MethodViewType):
@@ -116,7 +117,8 @@ def get(self, *args, **kwargs):
 
         qs = QSManager(request.args, self.schema)
 
-        objects_count, objects = self.get_collection(qs, kwargs)
+        parent_filter = self._get_parent_filter(request.url, kwargs)
+        objects_count, objects = self.get_collection(qs, kwargs, filters=parent_filter)
 
         schema_kwargs = getattr(self, 'get_schema_kwargs', dict())
         schema_kwargs.update({'many': True})
@@ -190,6 +192,23 @@ def post(self, *args, **kwargs):
 
         return result
 
+    def _get_parent_filter(self, url, kwargs):
+        """
+        Returns a dictionary of filters that should be applied to ensure only resources
+        belonging to the parent resource are returned
+        """
+
+        url_segments = url.split('/')
+        parent_segment = url_segments[-3]
+        parent_id = url_segments[-2]
+
+        for key, value in self.schema._declared_fields.items():
+            if isinstance(value, BaseRelationship):
+                if value.type_ == parent_segment:
+                    return {value.id_field: parent_id}
+
+        return {}
+
     def before_get(self, args, kwargs):
         """Hook to make custom work before get method"""
         pass
@@ -209,8 +228,8 @@ def after_post(self, result):
     def before_marshmallow(self, args, kwargs):
         pass
 
-    def get_collection(self, qs, kwargs):
-        return self._data_layer.get_collection(qs, kwargs)
+    def get_collection(self, qs, kwargs, filters=None):
+        return self._data_layer.get_collection(qs, kwargs, filters=filters)
 
     def create_object(self, data, kwargs):
         return self._data_layer.create_object(data, kwargs)