diff --git a/LICENSE b/LICENSE new file mode 100644 --- /dev/null +++ b/LICENSE @@ -0,0 +1,30 @@ +Copyright (c) 2010, Alexander Dunlap. + +All rights reserved. + +Redistribution and use in source and binary forms, with or without +modification, are permitted provided that the following conditions are met: + + * Redistributions of source code must retain the above copyright + notice, this list of conditions and the following disclaimer. + + * Redistributions in binary form must reproduce the above + copyright notice, this list of conditions and the following + disclaimer in the documentation and/or other materials provided + with the distribution. + + * Neither the name of Alexander Dunlap nor the names of other + contributors may be used to endorse or promote products derived + from this software without specific prior written permission. + +THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. diff --git a/Setup.hs b/Setup.hs new file mode 100644 --- /dev/null +++ b/Setup.hs @@ -0,0 +1,2 @@ +import Distribution.Simple +main = defaultMain diff --git a/Yesod/Paginate.hs b/Yesod/Paginate.hs new file mode 100644 --- /dev/null +++ b/Yesod/Paginate.hs @@ -0,0 +1,89 @@ +{-# LANGUAGE QuasiQuotes, TemplateHaskell, CPP, TypeFamilies, FlexibleInstances, MultiParamTypeClasses, FlexibleContexts #-} +-- | Provides a pagination subsite for Yesod. +-- +-- Route layout: +-- +-- > / PaginateHomeR GET +-- > /#Int PaginateStartR GET +-- > /#Int/#Int PaginateR GET +-- +-- If no numbers are given, display the items starting from the beginning with the default count. If one number is given, +-- display the items starting from that index with the default count. If two numbers are given, the first one is the count +-- and the second is the starting index. (This is so the user can modify the end of the URL to move forward in the pagination.) +module Yesod.Paginate + ( Paginate (..) + , PaginateRoute (..) + , defaultPaginate + , prevLink + , nextLink + ) + where + +import Yesod +import Control.Applicative +import Language.Haskell.TH.Syntax + +data Paginate master a = Paginate + { pgnDefaultCount :: Int -- ^ How many items to show per page by default + , pgnGetItems :: Int -> Int -> GHandler (Paginate master a) master [a] -- ^ Get a certain count of items at a certain offset + , pgnItemCount :: GHandler (Paginate master a) master Int -- ^ How many items there are in all + , pgnDisplayItems :: Int -> Int -> [a] -> GHandler (Paginate master a) master RepHtml -- ^ Render the items on a page given the count and offset + } + +mkYesodSub + "Paginate master a" + [ ClassP ''Yesod [VarT $ mkName "master"] + ] +#if GHC7 + [parseRoutes| +#else + [$parseRoutes| +#endif +/ PaginateHomeR GET +/#Int PaginateStartR GET +/#Int/#Int PaginateR GET +|] + +getPaginateHomeR :: GHandler (Paginate master a) master RepHtml +getPaginateHomeR = do + pgn <- getYesodSub + toMaster <- getRouteToMaster + redirect RedirectSeeOther (toMaster (PaginateR (pgnDefaultCount pgn) 0)) + +getPaginateStartR :: Int -> GHandler (Paginate master a) master RepHtml +getPaginateStartR start = do + pgn <- getYesodSub + toMaster <- getRouteToMaster + redirect RedirectSeeOther (toMaster (PaginateR (pgnDefaultCount pgn) start)) + +getPaginateR :: Int -> Int -> GHandler (Paginate master a) master RepHtml +getPaginateR howmany start = do + pgn <- getYesodSub + xs <- pgnGetItems pgn howmany start + pgnDisplayItems pgn howmany start xs + +defaultPaginate + :: (YesodPersist master, PersistBackend (YesodDB master (GHandler (Paginate master a) master)), PersistEntity a) + => Int -- ^ Default number of items to show + -> [Filter a] -- ^ Filters to apply + -> [Order a] -- ^ Ordering to apply + -> (Int -> Int -> [a] -> GHandler (Paginate master a) master RepHtml) -- ^ Display function + -> Paginate master a +defaultPaginate x fs os d = Paginate + { pgnDefaultCount = x + , pgnGetItems = \y z -> map snd <$> runDB (selectList fs os y z) + , pgnItemCount = runDB (count fs) + , pgnDisplayItems = d + } + +-- | Link to the previous page. +prevLink :: Paginate master a -> Int -> Int -> Maybe (Route (Paginate master a)) +prevLink p howmany start + | start > 0 = Just (PaginateR howmany (max 0 (start-howmany))) + | otherwise = Nothing + +-- | Link to the next page. +nextLink :: Paginate master a -> Int -> Int -> GHandler (Paginate master a) master (Maybe (Route (Paginate master a))) +nextLink p howmany start = go <$> pgnItemCount p where + go l | start < l-howmany-1 = Just (PaginateR howmany (start+howmany)) + | otherwise = Nothing diff --git a/yesod-paginate.cabal b/yesod-paginate.cabal new file mode 100644 --- /dev/null +++ b/yesod-paginate.cabal @@ -0,0 +1,36 @@ +-- yesod-markdown.cabal auto-generated by cabal init. For additional +-- options, see +-- http://www.haskell.org/cabal/release/cabal-latest/doc/users-guide/authors.html#pkg-descr. +Name: yesod-paginate +Version: 0.0 +Synopsis: Pagination for Yesod sites. +Description: +License: BSD3 +License-file: LICENSE +Author: Alexander Dunlap +Maintainer: alexander.dunlap@gmail.com +Copyright: (c) 2010 Alexander Dunlap +Category: Web, Yesod +Build-type: Simple +Stability: Alpha +-- Extra files to be distributed with the package, such as examples or +-- a README. +-- Extra-source-files: + +-- Constraint on the version of Cabal needed to build this package. +Cabal-version: >=1.6 + +flag ghc7 + +Library + if flag(ghc7) + build-depends: base >= 4.3 && < 5 + cpp-options: -DGHC7 + else + build-depends: base >= 4 && < 4.3 + Exposed-modules: Yesod.Paginate + Build-depends: yesod, template-haskell + +source-repository head + type: git + location: git://github.com/ajdunlap/yesod-paginate.git