From 70769f5609a25e0e2bbc4efff8fab10e19e54d62 Mon Sep 17 00:00:00 2001
From: Sergey Borisov <saborisov@sberned.ru>
Date: Wed, 28 Dec 2016 23:23:40 +0300
Subject: [PATCH] validate accepts kwargs; item_id is passed to validate in
 ItemHandler get/put/delete

---
 tcrudge/__init__.py |  2 +-
 tcrudge/handlers.py | 46 +++++++++++++++++++++++++--------------------
 2 files changed, 27 insertions(+), 21 deletions(-)

diff --git a/tcrudge/__init__.py b/tcrudge/__init__.py
index 0f225a3..d0bf91d 100644
--- a/tcrudge/__init__.py
+++ b/tcrudge/__init__.py
@@ -6,5 +6,5 @@
 Supports JSON and MessagePack responses.
 """
 
-__version__ = "0.8.0"
+__version__ = "0.8.1"
 
diff --git a/tcrudge/handlers.py b/tcrudge/handlers.py
index 9c1f54d..5c0e7dd 100644
--- a/tcrudge/handlers.py
+++ b/tcrudge/handlers.py
@@ -103,7 +103,7 @@ def write_error(self, status_code, **kwargs):
             self.write(getattr(exc_info[1], 'body', None))
         self.finish()
 
-    async def validate(self, data, schema):
+    async def validate(self, data, schema, **kwargs):
         """
         Method to validate parameters.
         Raises HTTPError(400) with error info for invalid data.
@@ -723,6 +723,10 @@ class ApiItemHandler(ApiHandler):
     Supports R, U, D from CRUDL.
     """
 
+    def __init__(self, *args, **kwargs):
+        super(ApiItemHandler, self).__init__(*args, **kwargs)
+        self._instance = None
+
     @property
     def get_schema_input(self):
         """
@@ -782,28 +786,30 @@ def delete_schema_output(self):  # pragma: no cover
     async def get_item(self, item_id):
         """
         Fetches item from database by PK.
+        Result is cached in self._instance for multiple calls
 
         :raises: HTTP 404 if no item found.
         :returns: raw object if exists.
         :rtype: ORM model instance.
         """
-        try:
-            return await self.application.objects.get(self.model_cls,
-                                                      **{
-                                                          self.model_cls._meta.primary_key.name: item_id})
-        except (self.model_cls.DoesNotExist, ValueError) as e:
-            raise HTTPError(
-                404,
-                body=self.get_response(
-                    errors=[
-                        {
-                            'code': '',
-                            'message': 'Item not found',
-                            'detail': str(e)
-                        }
-                    ]
+        if not self._instance:
+            try:
+                self._instance = await self.application.objects.get(self.model_cls,
+                                                                    **{self.model_cls._meta.primary_key.name: item_id})
+            except (self.model_cls.DoesNotExist, ValueError) as e:
+                raise HTTPError(
+                    404,
+                    body=self.get_response(
+                        errors=[
+                            {
+                                'code': '',
+                                'message': 'Item not found',
+                                'detail': str(e)
+                            }
+                        ]
+                    )
                 )
-            )
+        return self._instance
 
     async def get(self, item_id):
         """
@@ -813,7 +819,7 @@ async def get(self, item_id):
         2. Writes serialized object of ORM model instance to response.
         """
         await self.validate({k: self.get_argument(k) for k in self.request.query_arguments.keys()},
-                            self.get_schema_input)
+                            self.get_schema_input, item_id=item_id)
         item = await self.get_item(item_id)
 
         self.response(result=await self.serialize(item))
@@ -835,7 +841,7 @@ async def put(self, item_id):
         """
         item = await self.get_item(item_id)
 
-        data = await self.validate(self.request.body, self.put_schema_input)
+        data = await self.validate(self.request.body, self.put_schema_input, item_id=item_id)
         try:
             item = await item._update(self.application, data)
         except AttributeError as e:
@@ -881,7 +887,7 @@ async def delete(self, item_id):
         :raises: HTTPError 405 if model object is not deletable.
         """
         # DELETE usually does not have body to validate.
-        await self.validate(self.request.body or {}, self.delete_schema_input)
+        await self.validate(self.request.body or {}, self.delete_schema_input, item_id=item_id)
         item = await self.get_item(item_id)
         try:
             # We can only delete item if model method _delete() is implemented