Fixed Focus info popup by restoring post route (#1575)

Author: akarki2005

CHANGELOG.md

@@ -10,6 +10,8 @@
 
 ### 🐛 Bug fixes
 
+- Fixed a bug that was causing the focus info popup to appear blank
+
 ### 🔧 Internal changes
 
 - Refactored navigation bar into a React component (for the graph, grid and generate pages only - the about page navigation bar is still rendered using Blaze)

app/Database/CourseQueries.hs

@@ -9,7 +9,8 @@ and serve the information back to the client.
 -}
 
 module Database.CourseQueries
-    (returnPost,
+    (retrievePost,
+     returnPost,
      reqsForPost,
      prereqsForCourse,
      returnMeeting,
@@ -26,7 +27,29 @@ import qualified Data.Text as T (Text, append, isPrefixOf, snoc, tail, toUpper,
 import Database.Persist.Sqlite (Entity, PersistValue (PersistText), SqlPersistM, entityKey,
                                 entityVal, rawSql, selectFirst, selectList, (<-.), (==.))
 import Database.Tables as Tables
+import Happstack.Server.SimpleHTTP (Request, Response, ServerPart, askRq, ifModifiedSince,
+                                    lookText')
 import Models.Course (buildCourse, buildMeetTimes)
+import Util.Happstack (createJSONResponse)
+
+-- | Takes a http request with a post code and sends a JSON response containing the post data
+-- | if the post data has been modified since the timestamp in the request,
+-- | or a 304 "Not Modified" response otherwise
+retrievePost :: ServerPart Response
+retrievePost = do
+    req <- askRq
+    code <- lookText' "code"
+    liftIO $ queryPost req code
+
+-- | Queries the database for the post data then returns a JSON response of it
+-- | if the post data has been modified since the timestamp in the request,
+-- | or a 304 "Not Modified" response otherwise
+queryPost :: Request -> T.Text -> IO Response
+queryPost req code = do
+    postMaybe <- returnPost code
+    case postMaybe of
+        Nothing -> return $ createJSONResponse (Nothing :: Maybe Post)
+        Just post -> return $ ifModifiedSince (postModified post) req (createJSONResponse post)
 
 -- | Queries the database for information about the post then returns the post value
 returnPost :: T.Text -> IO (Maybe Post)

app/Routes.hs

@@ -7,6 +7,7 @@ import Controllers.Generate as GenerateController (findAndSavePrereqsResponse, g
 import Controllers.Graph as GraphsController (getGraphJSON, graphImageResponse, graphResponse,
                                               index, saveGraphJSON)
 import Controllers.Timetable as TimetableController
+import Database.CourseQueries (retrievePost)
 import Happstack.Server (Browsing (DisableBrowsing), Response, ServerPart, ServerPartT,
                          ToMessage (toResponse), dir, noTrailingSlash, nullDir, seeOther,
                          serveDirectory)
@@ -27,6 +28,7 @@ strictRoutes = [
     ("image", graphImageResponse),
     ("timetable-image", TimetableController.exportTimetableImageResponse),
     ("timetable-pdf", TimetableController.exportTimetablePDFResponse),
+    ("post", retrievePost),
     ("draw", drawResponse),
     ("about", aboutResponse),
     ("graphs", GraphsController.index),