以下の例では、nicEditor を textarea にバインドするためのスナップレットを定義しています。次の質問は、以下の例に関連するだけでなく、おそらく他の同様のケースにも関連しています..
- 初心者は以下の指示に従うことができますか (明確にする方法)?
- 例で使用する手順を少なくしたり、単純にしたりするにはどうすればよいですか? （以下とほぼ同じ内容で可能でしょうか？）
- これは解釈されたスプライスを使用しました。可能であれば、スナップレットもコンパイルされたスプライスを提供する必要がありますか?
- スナップレットは、通常の状況に対してデフォルトのハンドラーまたはいくつかのハンドラーを提供する可能性があります。また、ハンドラーは以下の「SnapNic.hs」で定義できます。ユーザーへの何らかのコールバック メカニズムですか?
--
{-# LANGUAGE TemplateHaskell #-}
{-# LANGUAGE OverloadedStrings #-}
------------------------------------------------------------------------------
-- | This module defines nicEditor snaplet, just a short example to show,
-- how snaplets can be defined together with splices.
-- License: BSD3.
-- Here are hopefully easy instructions, how to use or try:
--
-- 1. Make a directory, we'll use "netry" below, go there.
-- Initialize a project, e.g. "snap init default".
-- 2. Copy this file to netry/src-directory as SnapNic.hs.
-- 3. Add "import SnapNic" to Site.hs and to Application.hs
-- 4. Add ", _niced :: Snaplet Nicsnap" to data App in Application.hs
--
-- 5. Add "n <- nestSnaplet "niced" niced nicsnapInit" to
-- app :: SnapletInit App App in Site.hs.
-- 6. Add "addNicEditSplices n" to the same function as in step 5.
-- 7. Change the return-line of the same function as in step 5:
-- "return $ App h s a n"
-- that is, add "n" into the end. We need this because of step 4.
--
-- 8. Make route, e.g. ", ("/netext", with auth handleNEtext)" to
-- routes-function in Site.hs
--
-- 9. And then add handler into Site.hs:
-- handleNEtext :: Handler App v ()
-- handleNEtext = method GET handleForm <|> method POST handleFormSubmit
-- where
-- handleForm = render "textedit"
-- handleFormSubmit = do
-- p <- getParam "ots"
-- writeText "Submitting text from textarea...\n"
-- writeText (T.pack (show p))
--
-- 10. Last, add the following 2 templates to "netry/snaplets/heist/templates".
-- (This could be made simpler, but this works as an example of apply-tag.)
-- textedit.tpl:
-- <apply template="base">
-- <apply template="_textedit" />
-- </apply>
-- _textedit.tpl:
-- <h2>Your nic editor</h2>
-- <form method="post" action="netext">
-- <neTA/>
-- <button name="ne" value="ne" type="Submit">Send text</button>
-- </form>
-- <neScript/>
--
-- 11. Compile everything "cabal install -fdevelopment". After that,
-- if everything compiled, "netry -p 8000", start your browser and go
-- to "localhost:8000/netext".
--
-- TODO! This could use the config-files at least for some parameters, and more
-- tags,please. Tags could use some attributes (for example, size parameters
-- could be given as attributes of tags)...
--
module SnapNic
( Nicsnap (..)
, nicsnapInit
, addNicEditSplices
) where
------------------------------------------------------------------------------
import Control.Lens (makeLenses, view, (^.))
import qualified Data.Text as T (Text, append, pack)
import Data.Maybe (fromJust, fromMaybe)
import Snap.Core (MonadSnap)
import Snap.Snaplet (Snaplet
, makeSnaplet
, snapletValue
, SnapletInit
, Initializer
)
import Snap.Snaplet.Heist (HasHeist, addSplices)
import qualified Text.XmlHtml as X (Node (Element, TextNode))
import qualified Heist.Interpreted as I (Splice)
------------------------------------------------------------------------------
-- | Nicsnap has fields that can be used to set some basic properties.
-- The editor can have a title and its size can be set. Javascript can be
-- local or remote.
data Nicsnap = Nicsnap
{ _nicsnap :: T.Text -- title
, _areaSize :: (Int,Int) -- rows, cols
, _areaRef :: T.Text -- how to apply nicEditors?
-- (This may not be sufficient in order to refer in some other way, TODO!)
, _localR :: Maybe T.Text -- local route to nicEdit.js
, _webR :: T.Text -- route to nicEdit's javascript source.
}
makeLenses ''Nicsnap -- makes webR and other lenses
------------------------------------------------------------------------------
-- | Configurations are given here. This could use config-files...
-- What other things to configure?
-- If you want to make a local copy of the nicEdit, then add a static route
-- to the "routes"-function.
nicsnapInit :: SnapletInit b Nicsnap
nicsnapInit = makeSnaplet "nicsnap" "NicEditor snaplet " Nothing $ do
let m = "Nic editor title"
aS = (20,80)::(Int,Int) -- rows, cols
aR = "nicEditors.allTextAreas" -- TODO! We need to be able to tell,
-- which textareas have editors in a page.
lR = Nothing
-- lR = Just "/nicEdit.js"
-- If localR is nothing, then webR is used with the following addr.
wR = "http://js.nicedit.com/nicEdit-latest.js"
return $ Nicsnap m aS aR lR wR
------------------------------------------------------------------------------
-- | Internal, this makes the script-tag.
-- Input could be e.g. txt = "/nicEdit.js"
srcElem :: T.Text -> X.Node
srcElem txt = X.Element "script"
[("src",txt),("type","text/javascript")] []
-- | Internal, this makes the script-tag. At the moment this changes all
-- textareas to niceditors, if the example input below is used. TODO!...
-- Input could be e.g. txt = "nicEditors.allTextAreas"
srcOnLoad :: T.Text -> X.Node
srcOnLoad txt = X.Element "script" [("type","text/javascript")]
[X.TextNode (T.append (T.append "bkLib.onDomLoaded(" txt) ");")]
-- | Internal, used to define "divs", where we give a label and size to
-- textarea. Also ids and names.
-- TODO! ids and names could be parameters.
divLabelTX :: T.Text -> T.Text -> T.Text -> X.Node
divLabelTX title r c = X.Element "div" [("class", "required")]
[ X.Element "label" [("for","ots")]
[X.TextNode title]
, X.Element "textarea"
[("id","ots"), ("name","ots"), ("cols",c), ("rows",r)]
[X.TextNode " "]
]
-- | Internal, this can be used in splice-definition.
-- TODO! ids and names could be parameters, too.
nicTextAreaAdd :: MonadSnap m => T.Text -> (Int,Int) -> I.Splice m
nicTextAreaAdd title (r,c) = return [divLabelTX
title
(T.pack . show $ r)
(T.pack . show $ c)]
-- | Add script-tags to web page with splice that tell, what javascript
-- library to use...
nicEditAdd :: MonadSnap m => T.Text -> T.Text -> I.Splice m
nicEditAdd src edElems = return (srcElem src : [srcOnLoad edElems])
------------------------------------------------------------------------------
-- | Get the route to the javascript library that is applied (either local
-- library or construct a link to a web address).
nicRoute :: Nicsnap -> T.Text
nicRoute ns = let mlR = ns ^. localR in fromMaybe (ns ^. webR) mlR
------------------------------------------------------------------------------
-- | neTextAreaTag and neScripTag are used in addSplices to define the tags
-- to be used in templates.
-- What other tags could be useful? Maybe a way to add a nicEditor directly
-- with one or more button bind to it ("send", "clear", etc). TODO!
neTextAreaTag = "neTA" :: T.Text
neScriptTag = "neScript" :: T.Text
-- | Make the tags to be used in templates. At the moment, only the above
-- tags are defined.
addNicEditSplices :: HasHeist b => Snaplet Nicsnap -> Initializer b v ()
addNicEditSplices n = let m = view snapletValue n in addSplices
[(neTextAreaTag, nicTextAreaAdd (m ^. nicsnap) (m ^. areaSize))
,(neScriptTag, nicEditAdd (nicRoute m) (m ^. areaRef) )
]
------------------------------------------------------------------------------