groupwanted: New command to set the groupwanted preferred content expression.

Command/GroupWanted.hs

@@ -0,0 +1,45 @@
+{- git-annex command
+ -
+ - Copyright 2015 Joey Hess <id@joeyh.name>
+ -
+ - Licensed under the GNU GPL version 3 or higher.
+ -}
+
+module Command.GroupWanted where
+
+import Common.Annex
+import qualified Annex
+import Command
+import Logs.PreferredContent
+import Types.Messages
+import Types.Group
+
+import qualified Data.Map as M
+
+cmd :: [Command]
+cmd = [command "groupwanted" (paramPair paramGroup (paramOptional paramExpression)) seek
+	SectionSetup "get or set groupwanted expression"]
+
+seek :: CommandSeek
+seek = withWords start
+
+start :: [String] -> CommandStart
+start (g:[]) = next $ performGet g
+start (g:expr:[]) = do
+	showStart "groupwanted" g
+	next $ performSet g expr
+start _ = error "Specify a group."
+
+performGet :: Group -> CommandPerform
+performGet g = do
+	Annex.setOutput QuietOutput
+	m <- groupPreferredContentMapRaw
+	liftIO $ putStrLn $ fromMaybe "" $ M.lookup g m
+	next $ return True
+
+performSet :: Group -> String -> CommandPerform
+performSet g expr = case checkPreferredContentExpression expr of
+	Just e -> error $ "Parse error: " ++ e
+	Nothing -> do
+		groupPreferredContentSet g expr
+		next $ return True