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########################################################################
# $Header: /var/local/cvsroot/4Suite/Ft/Xml/Xslt/StylesheetHandler.py,v 1.58 2005/04/07 20:05:57 jkloth Exp $
"""
Stylesheet tree generator
Copyright 2004 Fourthought, Inc. (USA).
Detailed license and copyright information: http://4suite.org/COPYRIGHT
Project home, documentation, distributions: http://4suite.org/
"""
from Ft.Lib import Truncate, UriException
from Ft.Xml import XML_NAMESPACE, EMPTY_NAMESPACE, Domlette
from Ft.Xml.Lib.XmlString import IsXmlSpace
from Ft.Xml.Xslt import XSL_NAMESPACE, MessageSource
from Ft.Xml.Xslt import XsltException, XsltParserException, Error
from Ft.Xml.Xslt import CategoryTypes, BuiltInExtElements
from Ft.Xml.Xslt import Exslt
from LiteralElement import LiteralElement
from UndefinedElements import UndefinedXsltElement, UndefinedExtensionElement
import StylesheetTree, ContentInfo, AttributeInfo
# Table for load-on-demand of the XSLT elements
_ELEMENT_MAPPING = {
'apply-templates' : 'ApplyTemplatesElement.ApplyTemplatesElement',
'apply-imports' : 'ApplyImportsElement.ApplyImportsElement',
'attribute' : 'AttributeElement.AttributeElement',
'attribute-set' : 'AttributeSetElement.AttributeSetElement',
'call-template' : 'CallTemplateElement.CallTemplateElement',
'choose' : 'ChooseElement.ChooseElement',
'when' : 'ChooseElement.WhenElement',
'otherwise' : 'ChooseElement.OtherwiseElement',
'copy' : 'CopyElement.CopyElement',
'copy-of' : 'CopyOfElement.CopyOfElement',
'comment' : 'CommentElement.CommentElement',
'element' : 'ElementElement.ElementElement',
'for-each' : 'ForEachElement.ForEachElement',
'if' : 'IfElement.IfElement',
'message' : 'MessageElement.MessageElement',
'number' : 'NumberElement.NumberElement',
'param' : 'ParamElement.ParamElement',
'processing-instruction' : 'ProcessingInstructionElement.ProcessingInstructionElement',
'sort' : 'SortElement.SortElement',
'stylesheet' : 'Stylesheet.StylesheetElement',
'transform' : 'Stylesheet.StylesheetElement',
'template' : 'TemplateElement.TemplateElement',
'text' : 'TextElement.TextElement',
'variable' : 'VariableElement.VariableElement',
'value-of' : 'ValueOfElement.ValueOfElement',
'with-param' : 'WithParamElement.WithParamElement',
'import' : 'OtherXslElement.ImportElement',
'include' : 'OtherXslElement.IncludeElement',
'decimal-format' : 'OtherXslElement.DecimalFormatElement',
'key' : 'OtherXslElement.KeyElement',
'namespace-alias' : 'OtherXslElement.NamespaceAliasElement',
'output' : 'OtherXslElement.OutputElement',
'fallback' : 'OtherXslElement.FallbackElement',
'preserve-space' : 'WhitespaceElements.PreserveSpaceElement',
'strip-space' : 'WhitespaceElements.StripSpaceElement',
}
# The XSL attributes allowed on literal elements
_RESULT_ELEMENT_XSL_ATTRS = {
'exclude-result-prefixes' : AttributeInfo.Prefixes(),
'extension-element-prefixes' : AttributeInfo.Prefixes(),
'use-attribute-sets' : AttributeInfo.QNames(),
'version' : AttributeInfo.Number(),
}
_RESULT_ELEMENT_ATTR_INFO = AttributeInfo.AnyAvt()
_ELEMENT_CLASSES = {}
_LEGAL_ATTRS = {}
class ParseState:
"""
Stores the current state of the parser.
Constructor arguments/instance variables:
validation - validation state for the current containing node.
localVariables - set of in-scope variable bindings to determine
variable shadowing.
forwardsCompatible - flag indicating whether or not forwards-compatible
processing is enabled.
currentNamespaces - set of in-scope namespaces for the current node.
extensionNamespaces - set of namespaces defining extension elements
outputNamespaces - set of in-scope namespaces for literal result elements
"""
def __init__(self, node, validation, localVariables, forwardsCompatible,
currentNamespaces, extensionNamespaces, outputNamespaces):
self.node = node
self.validation = validation
self.localVariables = localVariables
self.forwardsCompatible = forwardsCompatible
self.currentNamespaces = currentNamespaces
self.extensionNamespaces = extensionNamespaces
self.outputNamespaces = outputNamespaces
return
class StylesheetHandler:
"""
Handles SAX events coming from the stylesheet parser,
in order to build the stylesheet tree.
"""
def __init__(self, importIndex=0, globalVars=None, extElements=None,
visitedStyUris=None, altBaseUris=None, ownerDocument=None):
self._import_index = importIndex
if globalVars is None:
# We need to make sure that the same dictionary is used
# through the entire processing (even if empty)
self._global_vars = {}
else:
self._global_vars = globalVars
if extElements is None:
self._extElements = d = {}
d.update(Exslt.ExtElements)
d.update(BuiltInExtElements.ExtElements)
else:
self._extElements = extElements
self._visited_stylesheet_uris = visitedStyUris or {}
self._alt_base_uris = altBaseUris or []
self._ownerDoc = ownerDocument
return
def reset(self):
self._global_vars = {}
self._import_index = 0
self._visited_stylesheet_uris = {}
self._ownerDoc = None
return
def clone(self):
return self.__class__(self._import_index, self._global_vars,
self._extElements, self._visited_stylesheet_uris,
self._alt_base_uris, self._ownerDoc)
def getResult(self):
return self._ownerDoc
def addExtensionElementMapping(self, elementMapping):
"""
Add a mapping of extension element names to classes to the
existing mapping of extension elements.
This should only be used for standalone uses of this class. The
only known standalone use for this class is for creating compiled
stylesheets. The benefits of compiled stylesheets are now so minor
that this use case may also disappear and then so will this function.
You have been warned.
"""
self._extElements = self._extElements.copy()
self._extElements.update(elementMapping)
return
# -- ContentHandler interface --------------------------------------
def setDocumentLocator(self, locator):
self._locator = locator
return
def startDocument(self):
"""
ownerDoc is supplied when processing an XSLT import or include.
"""
# Our root is always a document
# We use a document for this because of error checking and
# because we explicitly pass ownerDocument to the nodes as
# they are created
document_uri = self._locator.getSystemId()
root = StylesheetTree.XsltRoot(document_uri)
if not self._ownerDoc:
self._ownerDoc = root
# the stylesheet element instance
self._stylesheet = None
self._state_stack = [
ParseState(node=root,
validation=root.validator.getValidation(),
localVariables={},
forwardsCompatible=False,
currentNamespaces={'xml' : XML_NAMESPACE, None : None},
extensionNamespaces={},
outputNamespaces={})
]
# for recursive include checks for xsl:include/xsl:import
self._visited_stylesheet_uris[document_uri] = True
# namespaces added for the next element
self._new_namespaces = {}
return
def endDocument(self):
self._import_index += 1
self._locator = None
return
def startPrefixMapping(self, prefix, uri):
self._new_namespaces[prefix] = uri
return
def startElementNS(self, expandedName, qualifiedName, attribs):
state = ParseState(**self._state_stack[-1].__dict__)
# ----------------------------------------------------------
# update in-scope namespaces
if self._new_namespaces:
d = state.currentNamespaces = state.currentNamespaces.copy()
d.update(self._new_namespaces)
d = state.outputNamespaces = state.outputNamespaces.copy()
for prefix, uri in self._new_namespaces.items():
if uri not in (XML_NAMESPACE, XSL_NAMESPACE):
d[prefix] = uri
# reset for next element
self._new_namespaces = {}
# ----------------------------------------------------------
# get the class defining this element
namespace, local = expandedName
xsl_class = ext_class = None
category = CategoryTypes.RESULT_ELEMENT
if namespace == XSL_NAMESPACE:
try:
xsl_class = _ELEMENT_CLASSES[local]
except KeyError:
# We need to try to import (and cache) it
try:
module = _ELEMENT_MAPPING[local]
except KeyError:
if not state.forwardsCompatible:
raise XsltParserException(Error.XSLT_ILLEGAL_ELEMENT,
self._locator, local)
xsl_class = UndefinedXsltElement
else:
parts = module.split('.')
path = '.'.join(['Ft.Xml.Xslt'] + parts[:-1])
module = __import__(path, {}, {}, parts[-1:])
try:
xsl_class = module.__dict__[parts[-1]]
except KeyError:
raise ImportError('.'.join(parts))
_ELEMENT_CLASSES[local] = xsl_class
_LEGAL_ATTRS[xsl_class] = xsl_class.legalAttrs.items()
xsl_class.validator = ContentInfo.Validator(xsl_class.content)
category = xsl_class.category
elif namespace in state.extensionNamespaces:
try:
ext_class = self._extElements[(namespace, local)]
except KeyError:
ext_class = UndefinedExtensionElement
else:
if ext_class not in _LEGAL_ATTRS:
ext_class.validator = \
ContentInfo.Validator(ext_class.content)
legal_attrs = ext_class.legalAttrs
if legal_attrs is not None:
_LEGAL_ATTRS[ext_class] = legal_attrs.items()
# ----------------------------------------------------------
# verify that this element can be declared here
validation_else = ContentInfo.ELSE
if category is not None:
next = state.validation.get(category)
if next is None and validation_else in state.validation:
next = state.validation[validation_else].get(category)
else:
next = None
if next is None:
next = state.validation.get(expandedName)
if next is None and validation_else in state.validation:
next = state.validation[ContentInfo.ELSE].get(expandedName)
if next is None:
#self._debug_validation(expandedName)
parent = state.node
if parent is self._stylesheet:
if (XSL_NAMESPACE, 'import') == expandedName:
raise XsltParserException(Error.ILLEGAL_IMPORT,
self._locator)
elif parent.expandedName == (XSL_NAMESPACE, 'choose'):
if (XSL_NAMESPACE, 'otherwise') == expandedName:
raise XsltParserException(Error.ILLEGAL_CHOOSE_CHILD,
self._locator)
# ignore whatever elements are defined within an undefined
# element as an exception will occur when/if this element
# is actually instantiated
if not isinstance(parent, UndefinedExtensionElement):
raise XsltParserException(Error.ILLEGAL_ELEMENT_CHILD,
self._locator, qualifiedName,
parent.nodeName)
else:
# save this state for next go round
self._state_stack[-1].validation = next
# ----------------------------------------------------------
# create the instance defining this element
klass = (xsl_class or ext_class or LiteralElement)
instance = klass(self._ownerDoc, namespace, local,
self._locator.getSystemId())
instance.lineNumber = self._locator.getLineNumber()
instance.columnNumber = self._locator.getColumnNumber()
instance.importIndex = self._import_index
instance.namespaces = state.currentNamespaces
instance.nodeName = qualifiedName
# -- XSLT element --------------------------------------
if xsl_class:
# Handle attributes in the null-namespace
inst_dict = instance.__dict__
for attr_name, attr_info in _LEGAL_ATTRS[xsl_class]:
attr_expanded = (None, attr_name)
if attr_expanded in attribs:
value = attribs[attr_expanded]
del attribs[attr_expanded]
elif attr_info.required:
raise XsltParserException(
Error.MISSING_REQUIRED_ATTRIBUTE,
self._locator, qualifiedName, attr_name)
else:
value = None
try:
value = attr_info.prepare(instance, value)
except XsltException, e:
raise self._mutate_exception(e)
if local in ('stylesheet', 'transform'):
self._stylesheet = instance
self._handle_standard_attr(state, instance, attr_name,
value)
else:
if '-' in attr_name:
attr_name = attr_name.replace('-', '_')
inst_dict['_' + attr_name] = value
if attribs:
# Process attributes with a namespace-uri and check for
# any illegal attributes in the null-namespace
for expanded in attribs:
attr_ns, attr_name = expanded
if attr_ns is None:
if not state.forwardsCompatible:
raise XsltParserException(
Error.ILLEGAL_NULL_NAMESPACE_ATTR,
self._locator, attr_name, qualifiedName)
else:
instance.attributes[expanded] = attribs[expanded]
# XSLT Spec 2.6 - Combining Stylesheets
if local in ('import', 'include'):
self._combine_stylesheet(instance._href, (local == 'import'))
# -- extension element ---------------------------------
elif ext_class:
validate_attributes = (ext_class in _LEGAL_ATTRS)
if validate_attributes:
# Handle attributes in the null-namespace
inst_dict = instance.__dict__
for attr_name, attr_info in _LEGAL_ATTRS[ext_class]:
attr_expanded = (None, attr_name)
if attr_expanded in attribs:
value = attribs[attr_expanded]
del attribs[attr_expanded]
elif attr_info.required:
raise XsltParserException(
Error.MISSING_REQUIRED_ATTRIBUTE,
self._locator, qualifiedName, attr_name)
else:
value = None
try:
value = attr_info.prepare(instance, value)
except XsltException, e:
raise self_mutate_exception(e)
if '-' in attr_name:
attr_name = attr_name.replace('-', '_')
inst_dict['_' + attr_name] = value
# Process attributes with a namespace-uri and check for
# any illegal attributes in the null-namespace
if attribs:
for expanded in attribs:
attr_ns, attr_name = expanded
value = attribs[expanded]
if validate_attributes and attr_ns is None:
raise XsltParserException(
Error.ILLEGAL_NULL_NAMESPACE_ATTR, self._locator,
attr_name, qualifiedName)
elif attr_ns == XSL_NAMESPACE:
self._handle_result_element_attr(state, instance,
qualifiedName,
attr_name, value)
else:
instance.attributes[expanded] = value
# -- literal result element ----------------------------
else:
output_attrs = []
for expanded in attribs:
attr_ns, attr_local = expanded
value = attribs[expanded]
if attr_ns == XSL_NAMESPACE:
self._handle_result_element_attr(state, instance,
qualifiedName,
attr_local, value)
else:
instance.attributes[expanded] = value
# prepare attributes for literal output
value = _RESULT_ELEMENT_ATTR_INFO.prepare(instance, value)
attr_qname = attribs.getQNameByName(expanded)
output_attrs.append((attr_qname, attr_ns, value))
# save information for literal output
instance._output_namespace = namespace
instance._output_nss = state.outputNamespaces
instance._output_attrs = output_attrs
# Check for top-level result-element in null namespace
parent = state.node
if parent is self._stylesheet and \
not namespace and not state.forwardsCompatible:
raise XsltParserException(Error.ILLEGAL_ELEMENT_CHILD,
self._locator, qualifiedName,
parent.nodeName)
# ----------------------------------------------------------
# update depth information
state.node = instance
state.validation = instance.validator.getValidation()
self._state_stack.append(state)
if instance.doesPrime:
self._ownerDoc.primeInstructions.append(instance)
if instance.doesIdle:
self._ownerDoc.idleInstructions.append(instance)
return
def endElementNS(self, expandedName, qualifiedName):
state = self._state_stack.pop()
element = state.node
if len(self._state_stack) == 1 and isinstance(element, LiteralElement):
# a literal result element as stylesheet
try:
version = element._version
except AttributeError:
raise XsltParserException(Error.LITERAL_RESULT_MISSING_VERSION,
self._locator)
# FIXME: use the prefix from the document for the XSL namespace
stylesheet = (XSL_NAMESPACE, u'stylesheet')
self.startElementNS(stylesheet, u'xsl:stylesheet',
{(None, u'version') : version})
template = (XSL_NAMESPACE, u'template')
self.startElementNS(template, u'xsl:template',
{(None, u'match') : u'/'})
# make this element the template's content
self._state_stack[-1].node.appendChild(element)
self.endElementNS(template, u'xsl:template')
self.endElementNS(stylesheet, u'xsl:stylesheet')
else:
self._state_stack[-1].node.appendChild(element)
if expandedName in ((XSL_NAMESPACE, u'variable'),
(XSL_NAMESPACE, u'param')):
name = element._name
# one for the root and one for the stylesheet or
# a literal result element as stylesheet
if len(self._state_stack) > 2 or \
isinstance(self._state_stack[-1].node, LiteralElement):
# local variables
# it is safe to ignore import precedence here
local_vars = self._state_stack[-1].localVariables
if name in local_vars:
raise XsltParserException(Error.ILLEGAL_SHADOWING,
self._locator, name)
# Copy on use
if local_vars is self._state_stack[-2].localVariables:
local_vars = local_vars.copy()
self._state_stack[-1].localVariables = local_vars
local_vars[name] = True
else:
# global variables
existing = self._global_vars.get(name, -1)
if self._import_index > existing:
self._global_vars[name] = self._import_index
elif self._import_index == existing:
raise XsltParserException(Error.DUPLICATE_TOP_LEVEL_VAR,
self._locator, name)
return
def characters(self, data):
state = self._state_stack[-1]
# verify that the current element can have text children
validation = state.validation
token = ContentInfo.TEXT_NODE
next = validation.get(token)
if next is None and ContentInfo.ELSE in validation:
next = validation[ContentInfo.ELSE].get(token)
if next is None:
# If the parent can have element children, but not text nodes,
# ignore pure whitespace nodes. This clarification is from
# XSLT 2.0 [3.4] Whitespace Stripping.
# e.g. xsl:stylesheet, xsl:apply-templates, xsl:choose
if not (ContentInfo.EMPTY in validation and IsXmlSpace(data)):
raise XsltParserException(Error.ILLEGAL_TEXT_CHILD_PARSE,
self._locator,
repr(Truncate(data, 10)),
state.node.nodeName)
#self._debug_validation(expandedName)
else:
# update validation
state.validation = next
node = StylesheetTree.XsltText(self._ownerDoc,
self._locator.getSystemId(),
data)
state.node.appendChild(node)
return
# -- utility functions ---------------------------------------------
def _combine_stylesheet(self, href, is_import):
hint = is_import and 'STYLESHEET IMPORT' or 'STYLESHEET INCLUDE'
try:
new_source = self._input_source.resolve(href, pubid=None, hint=hint)
except (OSError, UriException):
for uri in self._alt_base_uris:
try:
new_href = self._input_source.getUriResolver().normalize(href, uri)
#Do we need to figure out a way to pass the hint here?
new_source = self._input_source.factory.fromUri(new_href)
break
except (OSError, UriException):
pass
else:
raise XsltParserException(Error.INCLUDE_NOT_FOUND,
self._locator, href,
self._locator.getSystemId())
# XSLT Spec 2.6.1, Detect circular references in stylesheets
# Note, it is NOT an error to include/import the same stylesheet
# multiple times, rather that it may lead to duplicate definitions
# which are handled regardless (variables, params, templates, ...)
if new_source.uri in self._visited_stylesheet_uris:
raise XsltParserException(Error.CIRCULAR_INCLUDE,
self._locator, new_source.uri)
else:
self._visited_stylesheet_uris[new_source.uri] = True
# Create a new reader to handle the inclusion
include = self.clone().fromSrc(new_source)
# Make sure we detect circular imports/includes, but not other duplicates
del self._visited_stylesheet_uris[new_source.uri]
# The stylesheet containing the import will always be one higher
# than the imported stylesheet.
#
# For example:
# stylesheet A imports stylesheets B and C in that order,
# stylesheet B imports stylesheet D,
# stylesheet C imports stylesheet E.
# The resulting import precedences are:
# A=4, C=3, E=2, B=1, D=0
# Always update the precedence from the included stylesheet
# because it may have contained imports thus increasing its
# import precedence.
import_index = include.importIndex + is_import
self._stylesheet.importIndex = self._import_index = import_index
# merge the top-level elements
self._stylesheet.children.extend(include.children)
for child in include.children:
child.parent = self._stylesheet
return
def _handle_standard_attr(self, state, instance, name, value):
if name == 'extension-element-prefixes':
# a whitespace separated list of prefixes
ext = state.extensionNamespaces = state.extensionNamespaces.copy()
out = state.outputNamespaces = state.outputNamespaces.copy()
for prefix in value:
# add the namespace URI to the set of extension namespaces
try:
uri = instance.namespaces[prefix]
except KeyError:
raise XsltParserException(Error.UNDEFINED_PREFIX,
self._locator,
prefix or '#default')
ext[uri] = True
# remove all matching namespace URIs
for output_prefix, output_uri in out.items():
if output_uri == uri:
del out[output_prefix]
elif name == 'exclude-result-prefixes':
# a whitespace separated list of prefixes
out = state.outputNamespaces = state.outputNamespaces.copy()
for prefix in value:
try:
uri = instance.namespaces[prefix]
except KeyError:
raise XsltParserException(Error.UNDEFINED_PREFIX,
self._locator,
prefix or '#default')
# remove all matching namespace URIs
for output_prefix, output_uri in out.items():
if output_uri == uri:
del out[output_prefix]
elif name == 'version':
# XSLT Spec 2.5 - Forwards-Compatible Processing
state.forwardsCompatible = (value != 1.0)
instance._version = value
else:
if '-' in name:
name = name.replace('-', '_')
instance.__dict__['_' + name] = value
return
def _handle_result_element_attr(self, state, instance, elementName,
attributeName, value):
try:
attr_info = _RESULT_ELEMENT_XSL_ATTRS[attributeName]
except KeyError:
raise XsltParserException(Error.ILLEGAL_XSL_NAMESPACE_ATTR,
self._locator, attributeName,
elementName)
value = attr_info.prepare(instance, value)
self._handle_standard_attr(state, instance, attributeName, value)
return
def _mutate_exception(self, exception):
msg = MessageSource.POSITION_INFO % (self._locator.getSystemId(),
self._locator.getLineNumber(),
self._locator.getColumnNumber(),
exception.message)
exception.message = msg
return exception
# -- debugging routines --------------------------------------------
def _debug_validation(self, token=None, next=None):
from pprint import pprint
state = self._state_stack[-1]
parent = state.node
print '='*60
print 'parent =',parent
print 'parent class =',parent.__class__
print 'content expression =', parent.validator
print 'initial validation'
pprint(parent.validator.getValidation())
print 'current validation'
pprint(state.validation)
if token:
print 'token', token
if next:
print 'next validation'
pprint(next)
print '='*60
return
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