########################################################################
# $Header: /var/local/cvsroot/4Suite/Ft/Xml/XPath/ParsedStep.py,v 1.6 2005/08/02 22:43:00 mbrown Exp $
"""
A parsed token that represents a step.
Copyright 2004 Fourthought, Inc. (USA).
Detailed license and copyright information: http://4suite.org/COPYRIGHT
Project home, documentation, distributions: http://4suite.org/
"""
from xml.dom import Node
from Ft.Xml.XPath import XPathTypes
class ParsedStep:
def __init__(self, axis, nodeTest, predicates=None):
self._axis = axis
self._nodeTest = nodeTest
self._predicates = predicates
return
def evaluate(self, context):
"""
Select a set of nodes from the axis, then filter through the node
test and the predicates.
"""
(node_set, reverse) = self._axis.select(context, self._nodeTest.match)
if self._predicates and len(node_set):
node_set = self._predicates.filter(node_set, context, reverse)
return node_set
select = evaluate
def pprint(self, indent=''):
print indent + str(self)
self._axis.pprint(indent + ' ')
self._nodeTest.pprint(indent + ' ')
self._predicates and self._predicates.pprint(indent + ' ')
def __str__(self):
return '<Step at %x: %s>' % (id(self), repr(self))
def __repr__(self):
result = repr(self._axis) + '::' + repr(self._nodeTest)
if self._predicates:
result = result + repr(self._predicates)
return result
class ParsedAbbreviatedStep:
def __init__(self, parent):
self.parent = parent
def evaluate(self, context):
if self.parent:
if context.node.nodeType == Node.ATTRIBUTE_NODE:
return [context.node.ownerElement]
return context.node.parentNode and [context.node.parentNode] or []
return [context.node]
select = evaluate
def pprint(self, indent=''):
print indent + str(self)
def __str__(self):
return '<AbbreviatedStep at %x: %s>' % (id(self), repr(self))
def __repr__(self):
return self.parent and '..' or '.'
# From the XPath 2.0 Working Draft
# Used by XPointer
class ParsedNodeSetFunction:
def __init__(self, function, predicates=None):
self._function = function
self._predicates = predicates
return
def evaluate(self, context):
"""
Select a set of nodes from the node-set function then filter
through the predicates.
"""
nodeset = self._function.evaluate(context)
if not isinstance(nodeset, Types.NodesetType):
raise TypeError("%s must be a node-set, not a %s" % (repr(self._function),
Types.g_xpathPrimitiveTypes.get(type(nodeset),
type(nodeset).__name__)))
if self._predicates and len(nodeset):
reverse = 0
nodeset = self._predicates.filter(nodeset, context, reverse)
return nodeset
select = evaluate
def pprint(self, indent=''):
print indent + str(self)
self._function.pprint(indent + ' ')
self._predicates and self._predicates.pprint(indent + ' ')
def __str__(self):
return '<Step at %x: %s>' % (id(self), repr(self))
def __repr__(self):
result = repr(self._function)
if self._predicates:
result = result + repr(self._predicates)
return result
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