, setStatus
, setHeader
, redirect
- , setETag
- , setLastModified
, setContentType
-- ** Writing a response body
{- ExaminingRequest 時に使用するアクション群 -}
+-- |Tell the system that the 'Resource' found an entity for the
+-- request URI. If this is a GET or HEAD request, a found entity means
+-- a datum to be replied. If this is a PUT or DELETE request, it means
+-- a datum which was stored for the URI up to now. It is an error to
+-- compute 'foundEntity' if this is a POST request.
+--
+-- Computation of 'foundEntity' performs \"If-Match\" test or
+-- \"If-None-Match\" test if possible. When those tests fail, the
+-- computation of 'Resource' immediately aborts with status \"412
+-- Precondition Failed\" or \"304 Not Modified\" depending on the
+-- situation.
+--
+-- If this is a GET or HEAD request, 'foundEntity' automatically puts
+-- \"ETag\" and \"Last-Modified\" headers into the response.
foundEntity :: ETag -> ClockTime -> Resource ()
foundEntity tag timeStamp
= do driftTo ExaminingRequest
method <- getMethod
when (method == GET || method == HEAD)
$ setHeader' "Last-Modified" $ formatHTTPDateTime timeStamp
+ when (method == POST)
+ $ abort InternalServerError []
+ (Just "Illegal computation of foundEntity for POST request.")
foundETag tag
driftTo GettingBody
-
+-- |Tell the system that the 'Resource' found an entity for the
+-- request URI. The only difference from 'foundEntity' is that
+-- 'foundETag' doesn't (and can't) put \"Last-Modified\" header into
+-- the response.
+--
+-- This action is not preferred. You should use 'foundEntity' when
+-- possible.
foundETag :: ETag -> Resource ()
foundETag tag
= do driftTo ExaminingRequest
method <- getMethod
when (method == GET || method == HEAD)
$ setHeader' "ETag" $ show tag
+ when (method == POST)
+ $ abort InternalServerError []
+ (Just "Illegal computation of foundETag for POST request.")
-- If-Match があればそれを見る。
ifMatch <- getHeader "If-Match"
driftTo GettingBody
-
+-- |Tell the system that the 'Resource' found an entity for the
+-- request URI. The only difference from 'foundEntity' is that
+-- 'foundTimeStamp' performs \"If-Modified-Since\" test or
+-- \"If-Unmodified-Since\" test instead of \"If-Match\" test or
+-- \"If-None-Match\" test. Be aware that any tests based on last
+-- modification time are unsafe because it is possible to mess up such
+-- tests by modifying the entity twice in a second.
+--
+-- This action is not preferred. You should use 'foundEntity' when
+-- possible.
foundTimeStamp :: ClockTime -> Resource ()
foundTimeStamp timeStamp
= do driftTo ExaminingRequest
method <- getMethod
when (method == GET || method == HEAD)
$ setHeader' "Last-Modified" $ formatHTTPDateTime timeStamp
+ when (method == POST)
+ $ abort InternalServerError []
+ (Just "Illegal computation of foundTimeStamp for POST request.")
let statusForIfModSince = if method == GET || method == HEAD then
NotModified
driftTo GettingBody
-
+-- |Computation of @'foundNoEntity' mStr@ tell the system that the
+-- 'Resource' found no entity for the request URI. @mStr@ is an
+-- optional error message to be replied to the client.
+--
+-- If this is a PUT request, 'foundNoEntity' performs \"If-Match\"
+-- test and aborts with status \"412 Precondition Failed\" when it
+-- failed. If this is a GET, HEAD or DELETE request, 'foundNoEntity'
+-- always aborts with status \"404 Not Found\". It is an error to
+-- compute 'foundNoEntity' if this is a POST request.
foundNoEntity :: Maybe String -> Resource ()
foundNoEntity msgM
= do driftTo ExaminingRequest
method <- getMethod
+ when (method == POST)
+ $ abort InternalServerError []
+ (Just "Illegal computation of foundNoEntity for POST request.")
when (method /= PUT)
- $ abort NotFound [] msgM
+ $ abort NotFound [] msgM
-- エンティティが存在しないと云ふ事は、"*" も含めたどのやうな
-- If-Match: 條件も滿たさない。
resStatus = code
}
-
+-- | Set a value of given resource header. Comparison of header name
+-- is case-insensitive. Note that this action is not intended to be
+-- used so frequently: there should be an action like 'setContentType'
+-- for every common headers.
+--
+-- Some important headers (especially \"Content-Length\" and
+-- \"Transfer-Encoding\") may be silently deleted or overwritten by
+-- the system not to corrupt the interaction with client at the
+-- viewpoint of HTTP protocol. For instance, if we are keeping
+-- connection alive, for an obvious reason it causes a catastrophe to
+-- send header \"Content-Length: 10\" and actually sending body of 20
+-- bytes long.
setHeader :: String -> String -> Resource ()
setHeader name value
= driftTo DecidingHeader >> setHeader' name value
setHeader "Location" (uriToString id uri $ "")
-setETag :: ETag -> Resource ()
-setETag tag
- = setHeader "ETag" $ show tag
-
-
-setLastModified :: ClockTime -> Resource ()
-setLastModified lastmod
- = setHeader "Last-Modified" $ formatHTTPDateTime lastmod
-
-
setContentType :: MIMEType -> Resource ()
setContentType mType
= setHeader "Content-Type" $ show mType
projects / Lucu.git / blobdiff