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Diffstat (limited to 'lib/pure/xmlparser.nim')
-rw-r--r-- | lib/pure/xmlparser.nim | 159 |
1 files changed, 159 insertions, 0 deletions
diff --git a/lib/pure/xmlparser.nim b/lib/pure/xmlparser.nim new file mode 100644 index 000000000..840cae734 --- /dev/null +++ b/lib/pure/xmlparser.nim @@ -0,0 +1,159 @@ +# +# +# Nim's Runtime Library +# (c) Copyright 2010 Andreas Rumpf +# +# See the file "copying.txt", included in this +# distribution, for details about the copyright. +# + +## This module parses an XML document and creates its XML tree representation. + +import streams, parsexml, strtabs, xmltree + +type + XmlError* = object of ValueError ## exception that is raised + ## for invalid XML + errors*: seq[string] ## all detected parsing errors + +{.deprecated: [EInvalidXml: XmlError].} + +proc raiseInvalidXml(errors: seq[string]) = + var e: ref XmlError + new(e) + e.msg = errors[0] + e.errors = errors + raise e + +proc addNode(father, son: XmlNode) = + if son != nil: add(father, son) + +proc parse(x: var XmlParser, errors: var seq[string]): XmlNode + +proc untilElementEnd(x: var XmlParser, result: XmlNode, + errors: var seq[string]) = + while true: + case x.kind + of xmlElementEnd: + if x.elementName == result.tag: + next(x) + else: + errors.add(errorMsg(x, "</" & result.tag & "> expected")) + # do not skip it here! + break + of xmlEof: + errors.add(errorMsg(x, "</" & result.tag & "> expected")) + break + else: + result.addNode(parse(x, errors)) + +proc parse(x: var XmlParser, errors: var seq[string]): XmlNode = + case x.kind + of xmlComment: + result = newComment(x.charData) + next(x) + of xmlCharData, xmlWhitespace: + result = newText(x.charData) + next(x) + of xmlPI, xmlSpecial: + # we just ignore processing instructions for now + next(x) + of xmlError: + errors.add(errorMsg(x)) + next(x) + of xmlElementStart: ## ``<elem>`` + result = newElement(x.elementName) + next(x) + untilElementEnd(x, result, errors) + of xmlElementEnd: + errors.add(errorMsg(x, "unexpected ending tag: " & x.elementName)) + of xmlElementOpen: + result = newElement(x.elementName) + next(x) + result.attrs = newStringTable() + while true: + case x.kind + of xmlAttribute: + result.attrs[x.attrKey] = x.attrValue + next(x) + of xmlElementClose: + next(x) + break + of xmlError: + errors.add(errorMsg(x)) + next(x) + break + else: + errors.add(errorMsg(x, "'>' expected")) + next(x) + break + untilElementEnd(x, result, errors) + of xmlAttribute, xmlElementClose: + errors.add(errorMsg(x, "<some_tag> expected")) + next(x) + of xmlCData: + result = newCData(x.charData) + next(x) + of xmlEntity: + ## &entity; + errors.add(errorMsg(x, "unknown entity: " & x.entityName)) + next(x) + of xmlEof: discard + +proc parseXml*(s: Stream, filename: string, + errors: var seq[string]): XmlNode = + ## parses the XML from stream `s` and returns a ``PXmlNode``. Every + ## occurred parsing error is added to the `errors` sequence. + var x: XmlParser + open(x, s, filename, {reportComments}) + while true: + x.next() + case x.kind + of xmlElementOpen, xmlElementStart: + result = parse(x, errors) + break + of xmlComment, xmlWhitespace, xmlSpecial, xmlPI: discard # just skip it + of xmlError: + errors.add(errorMsg(x)) + else: + errors.add(errorMsg(x, "<some_tag> expected")) + break + close(x) + +proc parseXml*(s: Stream): XmlNode = + ## parses the XTML from stream `s` and returns a ``PXmlNode``. All parsing + ## errors are turned into an ``EInvalidXML`` exception. + var errors: seq[string] = @[] + result = parseXml(s, "unknown_html_doc", errors) + if errors.len > 0: raiseInvalidXml(errors) + +proc loadXml*(path: string, errors: var seq[string]): XmlNode = + ## Loads and parses XML from file specified by ``path``, and returns + ## a ``PXmlNode``. Every occurred parsing error is added to the `errors` + ## sequence. + var s = newFileStream(path, fmRead) + if s == nil: raise newException(IOError, "Unable to read file: " & path) + result = parseXml(s, path, errors) + +proc loadXml*(path: string): XmlNode = + ## Loads and parses XML from file specified by ``path``, and returns + ## a ``PXmlNode``. All parsing errors are turned into an ``EInvalidXML`` + ## exception. + var errors: seq[string] = @[] + result = loadXml(path, errors) + if errors.len > 0: raiseInvalidXml(errors) + +when not defined(testing) and isMainModule: + import os + + var errors: seq[string] = @[] + var x = loadXml(paramStr(1), errors) + for e in items(errors): echo e + + var f: File + if open(f, "xmltest.txt", fmWrite): + f.write($x) + f.close() + else: + quit("cannot write test.txt") + |