{- Copyright (C) 2009 John MacFarlane <jgm@berkeley.edu> This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA -} {- | Interface for plugins. A plugin is a Haskell module that is dynamically loaded by gitit. There are three kinds of plugins: 'PageTransform's, 'PreParseTransform's, and 'PreCommitTransform's. These plugins differ chiefly in where they are applied. 'PreCommitTransform' plugins are applied just before changes to a page are saved and may transform the raw source that is saved. 'PreParseTransform' plugins are applied when a page is viewed and may alter the raw page source before it is parsed as a 'Pandoc' document. Finally, 'PageTransform' plugins modify the 'Pandoc' document that results after a page's source is parsed, but before it is converted to HTML: > +--------------------------+ > | edited text from browser | > +--------------------------+ > || <---- PreCommitTransform plugins > \/ > || <---- saved to repository > \/ > +---------------------------------+ > | raw page source from repository | > +---------------------------------+ > || <---- PreParseTransform plugins > \/ > || <---- markdown or RST reader > \/ > +-----------------+ > | Pandoc document | > +-----------------+ > || <---- PageTransform plugins > \/ > +---------------------+ > | new Pandoc document | > +---------------------+ > || <---- HTML writer > \/ > +----------------------+ > | HTML version of page | > +----------------------+ Note that 'PreParseTransform' and 'PageTransform' plugins do not alter the page source stored in the repository. They only affect what is visible on the website. Only 'PreCommitTransform' plugins can alter what is stored in the repository. Note also that 'PreParseTransform' and 'PageTransform' plugins will not be run when the cached version of a page is used. Plugins can use the 'doNotCache' command to prevent a page from being cached, if their behavior is sensitive to things that might change from one time to another (such as the time or currently logged-in user). You can use the helper functions 'mkPageTransform' and 'mkPageTransformM' to create 'PageTransform' plugins from a transformation of any of the basic types used by Pandoc (for example, @Inline@, @Block@, @[Inline]@, even @String@). Here is a simple (if silly) example: > -- Deprofanizer.hs > module Deprofanizer (plugin) where > > -- This plugin replaces profane words with "XXXXX". > > import Network.Gitit.Interface > import Data.Char (toLower) > > plugin :: Plugin > plugin = mkPageTransform deprofanize > > deprofanize :: Inline -> Inline > deprofanize (Str x) | isBadWord x = Str "XXXXX" > deprofanize x = x > > isBadWord :: String -> Bool > isBadWord x = (map toLower x) `elem` ["darn", "blasted", "stinker"] > -- there are more, but this is a family program Further examples can be found in the @plugins@ directory in the source distribution. If you have installed gitit using Cabal, you can also find them in the directory @CABALDIR\/share\/gitit-X.Y.Z\/plugins@, where @CABALDIR@ is the cabal install directory and @X.Y.Z@ is the version number of gitit. -} module Network.Gitit.Interface ( Plugin(..) , PluginM , mkPageTransform , mkPageTransformM , Config(..) , Request(..) , User(..) , Context(..) , PageType(..) , PageLayout(..) , askConfig , askUser , askRequest , askFileStore , askMeta , doNotCache , getContext , modifyContext , inlinesToURL , inlinesToString , liftIO , withTempDir , module Text.Pandoc.Definition , module Text.Pandoc.Generic ) where import Text.Pandoc.Definition import Text.Pandoc.Generic import Data.Data import Network.Gitit.Types import Network.Gitit.ContentTransformer import Network.Gitit.Util (withTempDir) import Network.Gitit.Server (Request(..)) import Control.Monad.Reader (ask) import Control.Monad.Trans (liftIO) import Control.Monad (liftM) import Data.FileStore (FileStore) -- | Returns the current wiki configuration. askConfig :: PluginM Config askConfig :: PluginM Config askConfig = (PluginData -> Config) -> ReaderT PluginData (StateT Context IO) PluginData -> PluginM Config forall (m :: * -> *) a1 r. Monad m => (a1 -> r) -> m a1 -> m r liftM PluginData -> Config pluginConfig ReaderT PluginData (StateT Context IO) PluginData forall r (m :: * -> *). MonadReader r m => m r ask -- | Returns @Just@ the logged in user, or @Nothing@ if nobody is logged in. askUser :: PluginM (Maybe User) askUser :: PluginM (Maybe User) askUser = (PluginData -> Maybe User) -> ReaderT PluginData (StateT Context IO) PluginData -> PluginM (Maybe User) forall (m :: * -> *) a1 r. Monad m => (a1 -> r) -> m a1 -> m r liftM PluginData -> Maybe User pluginUser ReaderT PluginData (StateT Context IO) PluginData forall r (m :: * -> *). MonadReader r m => m r ask -- | Returns the complete HTTP request. askRequest :: PluginM Request askRequest :: PluginM Request askRequest = (PluginData -> Request) -> ReaderT PluginData (StateT Context IO) PluginData -> PluginM Request forall (m :: * -> *) a1 r. Monad m => (a1 -> r) -> m a1 -> m r liftM PluginData -> Request pluginRequest ReaderT PluginData (StateT Context IO) PluginData forall r (m :: * -> *). MonadReader r m => m r ask -- | Returns the wiki filestore. askFileStore :: PluginM FileStore askFileStore :: PluginM FileStore askFileStore = (PluginData -> FileStore) -> ReaderT PluginData (StateT Context IO) PluginData -> PluginM FileStore forall (m :: * -> *) a1 r. Monad m => (a1 -> r) -> m a1 -> m r liftM PluginData -> FileStore pluginFileStore ReaderT PluginData (StateT Context IO) PluginData forall r (m :: * -> *). MonadReader r m => m r ask -- | Returns the page meta data askMeta :: PluginM [(String, String)] askMeta :: PluginM [(String, String)] askMeta = (Context -> [(String, String)]) -> ReaderT PluginData (StateT Context IO) Context -> PluginM [(String, String)] forall (m :: * -> *) a1 r. Monad m => (a1 -> r) -> m a1 -> m r liftM Context -> [(String, String)] ctxMeta ReaderT PluginData (StateT Context IO) Context forall (m :: * -> *). HasContext m => m Context getContext -- | Indicates that the current page or file is not to be cached. doNotCache :: PluginM () doNotCache :: PluginM () doNotCache = (Context -> Context) -> PluginM () forall (m :: * -> *). HasContext m => (Context -> Context) -> m () modifyContext (\Context ctx -> Context ctx{ ctxCacheable :: Bool ctxCacheable = Bool False }) -- | Lifts a function from @a -> a@ (for example, @Inline -> Inline@, -- @Block -> Block@, @[Inline] -> [Inline]@, or @String -> String@) -- to a 'PageTransform' plugin. mkPageTransform :: Data a => (a -> a) -> Plugin mkPageTransform :: (a -> a) -> Plugin mkPageTransform a -> a fn = (Pandoc -> PluginM Pandoc) -> Plugin PageTransform ((Pandoc -> PluginM Pandoc) -> Plugin) -> (Pandoc -> PluginM Pandoc) -> Plugin forall a b. (a -> b) -> a -> b $ Pandoc -> PluginM Pandoc forall (m :: * -> *) a. Monad m => a -> m a return (Pandoc -> PluginM Pandoc) -> (Pandoc -> Pandoc) -> Pandoc -> PluginM Pandoc forall b c a. (b -> c) -> (a -> b) -> a -> c . (a -> a) -> Pandoc -> Pandoc forall a b. (Data a, Data b) => (a -> a) -> b -> b bottomUp a -> a fn -- | Monadic version of 'mkPageTransform'. -- Lifts a function from @a -> m a@ to a 'PageTransform' plugin. mkPageTransformM :: Data a => (a -> PluginM a) -> Plugin mkPageTransformM :: (a -> PluginM a) -> Plugin mkPageTransformM = (Pandoc -> PluginM Pandoc) -> Plugin PageTransform ((Pandoc -> PluginM Pandoc) -> Plugin) -> ((a -> PluginM a) -> Pandoc -> PluginM Pandoc) -> (a -> PluginM a) -> Plugin forall b c a. (b -> c) -> (a -> b) -> a -> c . (a -> PluginM a) -> Pandoc -> PluginM Pandoc forall (m :: * -> *) a b. (Monad m, Data a, Data b) => (a -> m a) -> b -> m b bottomUpM