HaskellXHTML適用于手動輸入的資料，但不適用于從檔案中讀取的資料-有解無憂

我正在開發一個棋盤游戲，每個團隊必須每回合提交一個命令。為了防止濫用，我正在嘗試創建一個登錄頁面，您可以在其中選擇一個團隊，提供團隊的密碼，然后繼續下一頁。

我正在使用 Haskell，使用此處提供的資源，特別是“獲取用戶輸入”部分。

相關檔案：Network.CGI , Text.XHtml

匯入、相關資料/型別和頁面功能：

import Network.CGI
import Text.XHtml

data Team = Team
      {teamID :: Int,
     teamName :: String} deriving Eq
type Lang = Int
type Teams = [Team]

page :: String -> Html -> Html
page t b = header << thetitle << t     body << b

我有以下 loginPage 功能：

loginPage :: Lang -> Teams -> Html
loginPage lang teams = page (["Lépés Bejelentkezés", "Turn Login"] !! lang) $
  form ! [method "post"] << 
    -- [paragraph << (["Csapat: ", "Team: "] !! lang     (select ! [name "teamID"] << teamOpts)), -- Generated version, does not work
    {- -}
    [paragraph << (["Csapat: ", "Team: "] !! lang    
      (select ! [name "teamID"] <<
        [option ! [value "0"] << "Anglia", option ! [value "1"] << "Franciaország"])), --} -- Manually typed version, works perfectly
     paragraph << (["Jelszó: ", "Password: "] !! lang     password "password"),
     submit "" (["Tovább", "Next"] !! lang) ]
  where
    teamOpts = map (\t -> option ! [value . show $ teamID t] << teamName t) $ teams

注釋行使用 teamOpts 生成選項串列，并將它們放在選擇標簽中，名稱為“teamID”。在當前未注釋的行中，我寫了（部分）我在呼叫 teamOpts 時期望的串列。

在 ghci 中，兩種方法都生成完全相同的 HTML。然而，當在我的網路服務器（Rocky Linux 上的 Apache）上呼叫這個程式時，我得到以下輸出：

生成：

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml"
><head
  ><title
    >L&#233;p&#233;s Bejelentkez&#233;s</t

手動撰寫：

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml"
><head
  ><title
    >L&#233;p&#233;s Bejelentkez&#233;s</title
    ></head
  ><body
  ><form method="post"
    ><p
      >Csapat: <select name="teamID"
    ><option value="0"
      >Anglia</option
      ><option value="1"
      >Franciaorsz&#225;g</option
      ></select
    ></p
      ><p
      >Jelsz&#243;: <input type="password" name="password" id="password"
     /></p
      ><input type="submit" value="Tov&#225;bb"
       /></form
    ></body
  ></html
>

如您所見，生成的版本甚至在完成標題標簽之前就終止了。

在命令列（在網路服務器上）運行腳本時，我得到了預期的結果（與手動撰寫的相同），帶有 CGI Header: Content-type: text/html; charset=ISO-8859-1。我也將它設定為Content-type: text/html; charset=UTF-8，但同樣的問題仍然存在。

我嘗試過的其他事情：

在創建串列之前使用 (teams seq)，以及其他強制評估的方法（通常程式在回傳后終止<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/
嘗試使用更簡單的生成器進行除錯：（在 cli 中完美運行，但在加載時不能，回傳到 </t）

showTeams :: Teams -> Html
showTeams teams = page "Teams" $
  paragraph << (concat . map (\t -> teamName t    ", ") $ teams)

嘗試使用嚴格版本的 IO 函式（如此處推薦）。在 cli 中作業，但hGetContents: invalid argument (invalid byte sequence)在網路上給出了錯誤。
確保目錄中的所有內容都歸 apache:apache 所有

必要的代碼（newUnitsPage、cgiMain 和 main）：

newUnitsPage :: Lang -> Teams -> Units -> Maybe String -> Maybe String -> Html
newUnitsPage lang teams units tid passwd = page (["új egységek", "New units"] !! lang) body
  where
    body = paragraph << "PLACEHOLDER"     paragraph << fromJust tid     paragraph <<  fromJust passwd

cgiMain = do
  -- General setup
  liftIO $ hSetEncoding stdin utf8 -- This doesn't change anything either
  -- (What I use) {- -
  paths' <- liftIO $ listDirectory "./"
  let mapPaths = sort $ filter (=~ "\\.hmap$") paths'
  hmap <- liftIO $ getNewestMap mapPaths
  let teams = fetchTeams hmap --}
  {- For your convenience:
     Write the following to a file named "test.hmap":
     Team {teamID = 0, teamName = "Anglia"}
     Team {teamID = 1, teamName = "Franciaország"}
  -}
  test <- readFile "test.hmap" -- Pretty sure this is where it all goes wrong, but strict reading (Sysem.IO.Strict) does not fix it
  let teams = map (\line -> read line :: Team) . lines $ test

  -- Defaults to 0 (Hungarian)
  mlang <- getInput "lang"
  let lang = maybe 0 (\l -> if l `elem` ["1", "en"] then 1 else 0) mlang

  -- All Inputs
  -- Authentication
  tid <- getInput "teamID"
  password <- getInput "password"

  newUnitOrders <- getInput "newUnitOrders" -- This is for the next page, not yet implemented, since login doesn't work yet.

  -- Number coding for which form to show - method to show certain form based on what inputs exist
  let code = fromJust $ foldM (\lastCode (mInput, code) -> if isNothing mInput then Just lastCode else Just code)
        0 -- If username / password is not supplied, be on login page
        [(tid,1),(password,1), -- If newUnitOrders are not supplied, be on newUnit page
         (newUnitOrders,2)] -- Etc.

  -- The html output
  let pages =
        [loginPage lang teams,
        -- [showTeams teams,
         newUnitsPage lang teams units tid password]

  setHeader "Content-type" "text/html; charset=UTF-8" -- Optional
  output . renderHtml $ pages !! code

main = runCGI $ handleErrors cgiMain

我在檔案中一遍又一遍地檢查，我沒有發現出現什么問題的跡象。

謝謝你的幫助！

uj5u.com熱心網友回復：

我能夠復制你的test.hmap版本。檢查服務器錯誤日志，您應該會在 hmap 檔案中看到有關無效位元組序列的注釋，內容如下：

AH01215: xhtml.cgi: test.hmap: hGetContents: invalid argument (invalid
byte sequence): /usr/lib/cgi-bin/xhtml.cgi

問題似乎是 Apache 使用運行 CGI 腳本LANG=C，并且當 Haskell 腳本從您的一個 hmap 檔案中讀取 unicode 資料時，它會在某個隨機時間點終止。使評估更嚴格可能會導致腳本更早地失敗，但這并不能解決問題。

最簡單的解決方法可能是添加：

liftIO $ setLocaleEncoding utf8   -- from GHC.IO.Encoding

到你的cgiMain函式的頂部。stdin（在我的測驗中不需要更改編碼。）

這是我用于測驗的腳本的完整版本。沒有這liftIO $ setLocaleEncoding utf8條線，它會以與您觀察到的完全相同的方式截斷輸出；使用該行，它可以正常作業：

import Control.Monad
import Data.Maybe
import Data.List
import System.Directory
import System.IO
import Network.CGI
import Text.XHtml
import GHC.IO.Encoding

data Team = Team
      {teamID :: Int,
     teamName :: String} deriving (Read, Eq)
type Lang = Int
type Teams = [Team]

page :: String -> Html -> Html
page t b = header << thetitle << t     body << b

loginPage :: Lang -> Teams -> Html
loginPage lang teams = page (["Lépés Bejelentkezés", "Turn Login"] !! lang) $
  form ! [method "post"] <<
    [paragraph << (["Csapat: ", "Team: "] !! lang     (select ! [name "teamID"] << teamOpts)), -- Generated version, does not work
     paragraph << (["Jelszó: ", "Password: "] !! lang     password "password"),
     submit "" (["Tovább", "Next"] !! lang) ]
  where
    teamOpts = map (\t -> option ! [value . show $ teamID t] << teamName t) $ teams

cgiMain :: CGI CGIResult
cgiMain = do
  liftIO $ setLocaleEncoding utf8

  paths' <- liftIO $ listDirectory "./"
  test <- liftIO $ readFile "test.hmap" -- Pretty sure this is where it all goes wrong, but strict reading (Sysem.IO.Strict) does not fix it
  let teams = map (\line -> read line :: Team) . lines $ test

  -- Defaults to 0 (Hungarian)
  mlang <- getInput "lang"
  let lang = maybe 0 (\l -> if l `elem` ["1", "en"] then 1 else 0) mlang

  -- All Inputs
  -- Authentication
  tid <- getInput "teamID"
  password <- getInput "password"

  newUnitOrders <- getInput "newUnitOrders" -- This is for the next page, not yet implemented, since login doesn't work yet.

  -- Number coding for which form to show - method to show certain form based on what inputs exist
  let code = fromJust $ foldM (\lastCode (mInput, code) -> if isNothing mInput then Just lastCode else Just code)
        0 -- If username / password is not supplied, be on login page
        [(tid,1),(password,1), -- If newUnitOrders are not supplied, be on newUnit page
         (newUnitOrders,2)] -- Etc.

  -- The html output
  let pages =
        [loginPage lang teams]
        -- [showTeams teams,
        -- newUnitsPage lang teams units tid password]

  setHeader "Content-type" "text/html; charset=UTF-8" -- Optional
  output . renderHtml $ pages !! code

main :: IO ()
main = runCGI $ cgiMain

轉載請註明出處，本文鏈接：https://www.uj5u.com/shujuku/510595.html

標籤：html阿帕奇哈斯克尔xhtmlcgi

上一篇：以相同的方式將使用htaccess輸入的url重定向到不同的位置

下一篇：僅當它也不包含另一個特定單詞時，RewriteRule才匹配不包含點(.)的字串