implement select/return representation for DELETE queries (fix #518)

CHANGELOG.md

@@ -12,7 +12,7 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 - Accept posts from HTML forms - @begriffs
 - Ability to order embedded entities - @ruslantalpa
 - Ability to paginate using &limit and &offset parameters - @ruslantalpa
-- Ability to apply limits to embedded entities and enforce --max-rows on all levels - @ruslantalpa, @begriffs 
+- Ability to apply limits to embedded entities and enforce --max-rows on all levels - @ruslantalpa, @begriffs
 
 ### Fixed
 - Return 401 or 403 for access denied rather than 404 - @begriffs
@@ -22,6 +22,7 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 - Include entities from the same parent table using two different foreign keys - @ruslantalpa
 - Ensure that Location header in 201 response is URL-encoded - @league
 - Fix garbage collector CPU leak - @ruslantalpa et al.
+- Return deleted items when return=representation header is sent - @ruslantalpa
 
 ## [0.3.1.1] - 2016-03-28
 

src/PostgREST/ApiRequest.hs

@@ -150,9 +150,7 @@ userApiRequest schema req reqBody =
   , iPreferSingular = singular
   , iPreferCount = not $ singular || hasPrefer "count=none"
   , iFilters = [ (cs k, fromJust v) | (k,v) <- qParams, isJust v, k /= "select", k /= "offset", not (endingIn ["order", "limit"] k) ]
-  , iSelect = if method == "DELETE"
+  , iSelect = fromMaybe "*" $ fromMaybe (Just "*") $ lookup "select" qParams
-              then "*"
-              else fromMaybe "*" $ fromMaybe (Just "*") $ lookup "select" qParams
   , iOrder = [(cs k, fromJust v) | (k,v) <- qParams, isJust v, endingIn ["order"] k ]
   , iCanonicalQS = urlEncodeVars
      . sortBy (comparing fst)

src/PostgREST/App.hs

@@ -161,13 +161,16 @@ app dbStructure conf apiRequest =
         Left e -> return $ responseLBS status400 [jsonH] $ cs e
         Right (sq,mq) -> do
           let emptyUniform = UniformObjects V.empty
-          let fakeload = PayloadJSON emptyUniform
+              fakeload = PayloadJSON emptyUniform
-          let stm = createWriteStatement qi sq mq False (iPreferRepresentation apiRequest) [] (contentType == TextCSV) fakeload
+              stm = createWriteStatement qi sq mq False (iPreferRepresentation apiRequest) [] (contentType == TextCSV) fakeload
           row <- H.query emptyUniform stm
-          let (_, queryTotal, _, _) = extractQueryResult row
+          let (_, queryTotal, _, body) = extractQueryResult row
+              r = contentRangeH 1 0 (toInteger <$> Just queryTotal)
           return $ if queryTotal == 0
             then notFound
-            else responseLBS status204 [("Content-Range", "*/"<> cs (show queryTotal))] ""
+            else if iPreferRepresentation apiRequest == Full
+              then responseLBS status200 [contentTypeH, r] (cs body)
+              else responseLBS status204 [r] ""
 
     (ActionInfo, TargetIdent (QualifiedIdentifier tSchema tTable), Nothing) ->
       if isJust $ find (\t -> tableName t == tTable && tableSchema t == tSchema) (dbTables dbStructure)
@@ -346,6 +349,7 @@ buildReadRequest maxRows allRels apiRequest  =
     relations = case action of
       ActionCreate -> fakeSourceRelations ++ allRels
       ActionUpdate -> fakeSourceRelations ++ allRels
+      ActionDelete -> fakeSourceRelations ++ allRels
       _       -> allRels
       where fakeSourceRelations = mapMaybe (toSourceRelation rootTableName) allRels -- see comment in toSourceRelation
 

test/Feature/DeleteSpec.hs

@@ -19,6 +19,28 @@ spec =
           , matchHeaders = ["Content-Range" <:> "*/1"]
           }
 
+      it "returns the deleted item" $
+        request methodDelete "/items?id=eq.2" [("Prefer", "return=representation")] ""
+          `shouldRespondWith` ResponseMatcher {
+            matchBody    = Just [str|[{"id":2}]|]
+          , matchStatus  = 200
+          , matchHeaders = ["Content-Range" <:> "*/1"]
+          }
+      it "returns the deleted item and shapes the response" $
+        request methodDelete "/complex_items?id=eq.2&select=id,name" [("Prefer", "return=representation")] ""
+          `shouldRespondWith` ResponseMatcher {
+            matchBody    = Just [str|[{"id":2,"name":"Two"}]|]
+          , matchStatus  = 200
+          , matchHeaders = ["Content-Range" <:> "*/1"]
+          }
+      it "can embed (parent) entities" $
+        request methodDelete "/tasks?id=eq.8&select=id,name,project{id}" [("Prefer", "return=representation")] ""
+          `shouldRespondWith` ResponseMatcher {
+            matchBody    = Just [str|[{"id":8,"name":"Code OSX","project":{"id":4}}]|]
+          , matchStatus  = 200
+          , matchHeaders = ["Content-Range" <:> "*/1"]
+          }
+
       it "actually clears items ouf the db" $ do
         _ <- request methodDelete "/items?id=lt.15" [] ""
         get "/items"