diff options
Diffstat (limited to 'src/Text/Hakyll/RenderAction.hs')
| -rw-r--r-- | src/Text/Hakyll/RenderAction.hs | 74 |
1 files changed, 48 insertions, 26 deletions
diff --git a/src/Text/Hakyll/RenderAction.hs b/src/Text/Hakyll/RenderAction.hs index cec1a9f..e458eac 100644 --- a/src/Text/Hakyll/RenderAction.hs +++ b/src/Text/Hakyll/RenderAction.hs @@ -21,49 +21,50 @@ import Text.Hakyll.Context import Text.Hakyll.File (toDestination, isFileMoreRecent) import Text.Hakyll.Hakyll +-- | Type used for rendering computations that carry along dependencies. data RenderAction a b = RenderAction - { actionDependencies :: [FilePath] - , actionUrl :: Maybe (Hakyll FilePath) - , actionFunction :: a -> Hakyll b + { -- | Dependencies of the @RenderAction@. + actionDependencies :: [FilePath] + , -- | URL pointing to the result of this @RenderAction@. + actionUrl :: Maybe (Hakyll FilePath) + , -- | The actual render function. + actionFunction :: a -> Hakyll b } -createRenderAction :: (a -> Hakyll b) -> RenderAction a b +-- | Create a @RenderAction@ from a function. +createRenderAction :: (a -> Hakyll b) -- ^ Function to execute. + -> RenderAction a b createRenderAction f = id { actionFunction = f } -createSimpleRenderAction :: Hakyll b -> RenderAction () b +-- | Create a @RenderAction@ from a simple @Hakyll@ value. +createSimpleRenderAction :: Hakyll b -- ^ Hakyll value to pass on. + -> RenderAction () b createSimpleRenderAction = createRenderAction . const -createFileRenderAction :: FilePath -> Hakyll b -> RenderAction () b +-- | Create a @RenderAction@ that operates on one file. +createFileRenderAction :: FilePath -- ^ File to operate on. + -> Hakyll b -- ^ Value to pass on. + -> RenderAction () b -- ^ The resulting action. createFileRenderAction path action = RenderAction { actionDependencies = [path] , actionUrl = Just $ return path , actionFunction = const action } -instance Category RenderAction where - id = RenderAction - { actionDependencies = [] - , actionUrl = Nothing - , actionFunction = return - } - - x . y = RenderAction - { actionDependencies = actionDependencies x ++ actionDependencies y - , actionUrl = actionUrl y `mplus` actionUrl x - , actionFunction = actionFunction x <=< actionFunction y - } - -createManipulationAction :: ContextManipulation -> RenderAction Context Context +-- | Create a @RenderAction@ from a @ContextManipulation@. +createManipulationAction :: ContextManipulation -- ^ Manipulation to apply. + -> RenderAction Context Context createManipulationAction = createRenderAction . (return .) -chain :: [RenderAction a a] -> RenderAction a a -chain [] = id -chain list@(_:_) = foldl1 (>>>) list - -runRenderAction :: RenderAction () a -> Hakyll a +-- | Run a @RenderAction@ now. +runRenderAction :: RenderAction () a -- ^ Render action to run. + -> Hakyll a -- ^ Result of the action. runRenderAction action = actionFunction action () -runRenderActionIfNeeded :: RenderAction () () -> Hakyll () +-- | Run a @RenderAction@, but only when it is out-of-date. At this point, the +-- @actionUrl@ field must be set. +runRenderActionIfNeeded :: RenderAction () () -- ^ Action to run. + -> Hakyll () -- ^ Empty result. runRenderActionIfNeeded action = do url <- case actionUrl action of (Just u) -> u @@ -73,4 +74,25 @@ runRenderActionIfNeeded action = do unless valid $ do liftIO $ hPutStrLn stderr $ "Rendering " ++ destination runRenderAction action +-- | Chain a number of @RenderAction@ computations. +chain :: [RenderAction a a] -- ^ Actions to chain. + -> RenderAction a a -- ^ Resulting action. +chain [] = id +chain list@(_:_) = foldl1 (>>>) list + +-- | This is a specialized version of @RenderAction@, a @Context@ that can be +-- rendered. type Renderable = RenderAction () Context + +instance Category RenderAction where + id = RenderAction + { actionDependencies = [] + , actionUrl = Nothing + , actionFunction = return + } + + x . y = RenderAction + { actionDependencies = actionDependencies x ++ actionDependencies y + , actionUrl = actionUrl y `mplus` actionUrl x + , actionFunction = actionFunction x <=< actionFunction y + } |