git-annex/Command/View.hs
Joey Hess dd7b99c860 add tip about metadata driven views (and more flexible view filtering)
While writing this documentation, I realized that there needed to be a way
to stay in a view like tag=* while adding a filter like tag=work that
applies to the same field.

So, there are really two ways a view can be refined. It can have a new
"field=explicitvalue" filter added to it, which does not change the
"shape" of the view, but narrows the files it shows.
Or, it can have a new view added, which adds another level of
subdirectories.

So, added a vfilter command, which takes explicit values to add to the
filter, and rejects changes that would change the shape of the view.

And, made vadd only accept changes that change the shape of the view.

And, changed the View data type slightly; now components that can match
multiple metadata values can be visible, or not visible.

This commit was sponsored by Stelian Iancu.
2014-02-19 16:29:56 -04:00

90 lines
2.5 KiB
Haskell

{- git-annex command
-
- Copyright 2014 Joey Hess <joey@kitenet.net>
-
- Licensed under the GNU GPL version 3 or higher.
-}
module Command.View where
import Common.Annex
import Command
import qualified Git
import qualified Git.Command
import qualified Git.Ref
import qualified Git.Branch
import Types.MetaData
import Types.View
import Annex.View
import Logs.View
def :: [Command]
def = [notBareRepo $ notDirect $
command "view" paramView seek SectionMetaData "enter a view branch"]
seek :: CommandSeek
seek = withWords start
start :: [String] -> CommandStart
start [] = error "Specify metadata to include in view"
start params = do
showStart "view" ""
view <- mkView params
go view =<< currentView
where
go view Nothing = next $ perform view
go view (Just v)
| v == view = stop
| otherwise = error "Already in a view. Use 'git annex vadd' to further refine this view."
perform :: View -> CommandPerform
perform view = do
showSideAction "searching"
next $ checkoutViewBranch view applyView
paramView :: String
paramView = paramPair (paramRepeating "FIELD=VALUE") (paramRepeating "TAG")
parseViewParam :: String -> (MetaField, String)
parseViewParam s = case separate (== '=') s of
(tag, []) -> (tagMetaField, tag)
(field, wanted) -> either error (\f -> (f, wanted)) (mkMetaField field)
mkView :: [String] -> Annex View
mkView params = do
v <- View <$> viewbranch <*> pure []
return $ fst $ refineView v $
map parseViewParam $ reverse params
where
viewbranch = fromMaybe (error "not on any branch!")
<$> inRepo Git.Branch.current
checkoutViewBranch :: View -> (View -> Annex Git.Branch) -> CommandCleanup
checkoutViewBranch view mkbranch = do
oldcwd <- liftIO getCurrentDirectory
{- Change to top of repository before creating view branch. -}
liftIO . setCurrentDirectory =<< fromRepo Git.repoPath
branch <- mkbranch view
showOutput
ok <- inRepo $ Git.Command.runBool
[ Param "checkout"
, Param (Git.fromRef $ Git.Ref.base branch)
]
when ok $ do
setView view
{- A git repo can easily have empty directories in it,
- and this pollutes the view, so remove them. -}
liftIO $ removeemptydirs "."
unlessM (liftIO $ doesDirectoryExist oldcwd) $ do
top <- fromRepo Git.repoPath
showLongNote (cwdmissing top)
return ok
where
removeemptydirs top = mapM_ (tryIO . removeDirectory)
=<< dirTreeRecursiveSkipping (".git" `isSuffixOf`) top
cwdmissing top = unlines
[ "This view does not include the subdirectory you are currently in."
, "Perhaps you should: cd " ++ top
]