hxt-9.0.1: A collection of tools for processing XML with Haskell.Source codeContentsIndex
Text.XML.HXT.Arrow.XmlState.ErrorHandling
Portabilityportable
Stabilitystable
MaintainerUwe Schmidt (uwe@fh-wedel.de)
Description

the basic state arrows for XML processing

A state is needed for global processing options, like encoding options, document base URI, trace levels and error message handling

The state is separated into a user defined state and a system state. The system state contains variables for error message handling, for tracing, for the document base for accessing XML documents with relative references, e.g. DTDs, and a global key value store. This assoc list has strings as keys and lists of XmlTrees as values. It is used to store arbitrary XML and text values, e.g. user defined global options.

The user defined part of the store is in the default case empty, defined as (). It can be extended with an arbitray data type

Synopsis
changeErrorStatus :: (Int -> Int -> Int) -> IOStateArrow s Int Int
clearErrStatus :: IOStateArrow s b b
setErrStatus :: IOStateArrow s Int Int
getErrStatus :: IOStateArrow s XmlTree Int
setErrMsgStatus :: IOStateArrow s XmlTree XmlTree
setErrorMsgHandler :: Bool -> (String -> IO ()) -> IOStateArrow s b b
sysErrorMsg :: IOStateArrow s XmlTree XmlTree
errorMsgStderr :: IOStateArrow s b b
errorMsgCollect :: IOStateArrow s b b
errorMsgStderrAndCollect :: IOStateArrow s b b
errorMsgIgnore :: IOStateArrow s b b
getErrorMessages :: IOStateArrow s b XmlTree
addToErrorMsgList :: IOStateArrow s XmlTree XmlTree
filterErrorMsg :: IOStateArrow s XmlTree XmlTree
issueWarn :: String -> IOStateArrow s b b
issueErr :: String -> IOStateArrow s b b
issueFatal :: String -> IOStateArrow s b b
issueExc :: String -> IOStateArrow s SomeException b
setDocumentStatus :: Int -> String -> IOStateArrow s XmlTree XmlTree
setDocumentStatusFromSystemState :: String -> IOStateArrow s XmlTree XmlTree
documentStatusOk :: ArrowXml a => a XmlTree XmlTree
errorOutputToStderr :: String -> IO ()
Documentation
changeErrorStatus :: (Int -> Int -> Int) -> IOStateArrow s Int IntSource
clearErrStatus :: IOStateArrow s b bSource
reset global error variable
setErrStatus :: IOStateArrow s Int IntSource
set global error variable
getErrStatus :: IOStateArrow s XmlTree IntSource
read current global error status
setErrMsgStatus :: IOStateArrow s XmlTree XmlTreeSource
raise the global error status level to that of the input tree
setErrorMsgHandler :: Bool -> (String -> IO ()) -> IOStateArrow s b bSource
set the error message handler and the flag for collecting the errors
sysErrorMsg :: IOStateArrow s XmlTree XmlTreeSource
error message handler for output to stderr
errorMsgStderr :: IOStateArrow s b bSource
the default error message handler: error output to stderr
errorMsgCollect :: IOStateArrow s b bSource
error message handler for collecting errors
errorMsgStderrAndCollect :: IOStateArrow s b bSource
error message handler for output to stderr and collecting
errorMsgIgnore :: IOStateArrow s b bSource
error message handler for ignoring errors
getErrorMessages :: IOStateArrow s b XmlTreeSource
if error messages are collected by the error handler for processing these messages by the calling application, this arrow reads the stored messages and clears the error message store
addToErrorMsgList :: IOStateArrow s XmlTree XmlTreeSource
filterErrorMsg :: IOStateArrow s XmlTree XmlTreeSource
filter error messages from input trees and issue errors
issueWarn :: String -> IOStateArrow s b bSource
generate a warnig message
issueErr :: String -> IOStateArrow s b bSource
generate an error message
issueFatal :: String -> IOStateArrow s b bSource
generate a fatal error message, e.g. document not found
issueExc :: String -> IOStateArrow s SomeException bSource

Default exception handler: issue a fatal error message and fail.

The parameter can be used to specify where the error occured

setDocumentStatus :: Int -> String -> IOStateArrow s XmlTree XmlTreeSource
add the error level and the module where the error occured to the attributes of a document root node and remove the children when level is greater or equal to c_err. called by setDocumentStatusFromSystemState when the system state indicates an error
setDocumentStatusFromSystemState :: String -> IOStateArrow s XmlTree XmlTreeSource
check whether the error level attribute in the system state is set to error, in this case the children of the document root are removed and the module name where the error occured and the error level are added as attributes with setDocumentStatus else nothing is changed
documentStatusOk :: ArrowXml a => a XmlTree XmlTreeSource
check whether tree is a document root and the status attribute has a value less than c_err
errorOutputToStderr :: String -> IO ()Source
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