/*
* (C) Copyright The MITRE Corporation 1999 All rights reserved.
*
* The contents of this file are subject to the Mozilla Public License
* Version 1.0 (the "License"); you may not use this file except in
* compliance with the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* The program provided "as is" without any warranty express or
* implied, including the warranty of non-infringement and the implied
* warranties of merchantibility and fitness for a particular purpose.
* The Copyright owner will not be liable for any damages suffered by
* you as a result of using the Program. In no event will the Copyright
* owner be liable for any special, indirect or consequential damages or
* lost profits even if the Copyright owner has been advised of the
* possibility of their occurrence.
*
* Please see release.txt distributed with this file for more information.
*
*/
/**
* LocationStep
* @author Keith Visco
**/
#include "Expr.h"
/**
* Creates a new LocationStep using the default Axis Identifier and no
* NodeExpr (which matches nothing)
**/
LocationStep::LocationStep() : PredicateList() {
nodeExpr = 0;
this->axisIdentifier = CHILD_AXIS;
} //-- LocationStep
/**
* Creates a new LocationStep using the default Axis Identifier and
* the given NodeExpr
* @param nodeExpr the NodeExpr to use when matching Nodes
**/
LocationStep::LocationStep(NodeExpr* nodeExpr) : PredicateList() {
this->nodeExpr = nodeExpr;
this->axisIdentifier = CHILD_AXIS;
} //-- LocationStep
/**
* Creates a new LocationStep using the given NodeExpr and Axis Identifier
* @param nodeExpr the NodeExpr to use when matching Nodes
* @param axisIdentifier the Axis Identifier in which to search for nodes
**/
LocationStep::LocationStep(NodeExpr* nodeExpr, short axisIdentifier) : PredicateList() {
this->nodeExpr = nodeExpr;
this->axisIdentifier = axisIdentifier;
} //-- LocationStep
/**
* Destroys this LocationStep
* All predicates will be deleted
* The NodeExpr will be deleted
**/
LocationStep::~LocationStep() {
delete nodeExpr;
} //-- ~LocationStep
/**
* Sets the Axis Identifier for this LocationStep
* @param axisIdentifier the Axis in which to search for nodes
**/
void LocationStep::setAxisIdentifier(short axisIdentifier) {
this->axisIdentifier = axisIdentifier;
} //-- setAxisIdentifier
/**
* Sets the NodeExpr of this LocationStep for use when matching nodes
* @param nodeExpr the NodeExpr to use when matching nodes
**/
void LocationStep::setNodeExpr(NodeExpr* nodeExpr) {
this->nodeExpr = nodeExpr;
} //-- setNodeExpr
//------------------------------------/
//- Virtual methods from PatternExpr -/
//------------------------------------/
/**
* Evaluates this Expr based on the given context node and processor state
* @param context the context node for evaluation of this Expr
* @param ps the ProcessorState containing the stack information needed
* for evaluation
* @return the result of the evaluation
* @see PatternExpr
**/
ExprResult* LocationStep::evaluate(Node* context, ContextState* cs) {
NodeSet* nodes = new NodeSet();
if (( !context ) || (! nodeExpr )) return nodes;
Node* node = context;
switch (axisIdentifier) {
case ANCESTOR_AXIS :
if (node) node = context->getParentNode();
//-- do not break here
case ANCESTOR_OR_SELF_AXIS :
while (node) {
if (nodeExpr->matches(node, context, cs)) {
nodes->add(node);
}
node = node->getParentNode();
}
break;
case ATTRIBUTE_AXIS :
{
NamedNodeMap* atts = context->getAttributes();
if ( atts ) {
for ( int i = 0; i < atts->getLength(); i++ ) {
Attr* attr = (Attr*)atts->item(i);
if ( nodeExpr->matches(attr, context, cs) ) nodes->add(attr);
}
}
break;
}
case DESCENDANT_OR_SELF_AXIS :
if ( nodeExpr->matches(context, context, cs))
nodes->add(context);
//-- do not break here
case DESCENDANT_AXIS :
fromDescendants(context, cs, nodes);
break;
case FOLLOWING_AXIS :
{
node = context->getNextSibling();
while (node) {
if (nodeExpr->matches(node, context, cs))
nodes->add(node);
if (node->hasChildNodes())
fromDescendants(node, cs, nodes);
Node* tmpNode = node->getNextSibling();
if (!tmpNode) {
node = node->getParentNode();
if ((node) && (node->getNodeType() != Node::DOCUMENT_NODE))
node = node->getNextSibling();
}
else node = tmpNode;
}
break;
}
case FOLLOWING_SIBLING_AXIS :
node = context->getNextSibling();
while (node) {
if (nodeExpr->matches(node, context, cs))
nodes->add(node);
node = node->getNextSibling();
}
break;
case NAMESPACE_AXIS : //-- not yet implemented
cout << "namespace axis not yet implemented"<getParentNode();
if ( nodeExpr->matches(parent, context, cs) )
nodes->add(parent);
break;
}
case PRECEDING_AXIS :
node = context->getPreviousSibling();
if ( !node ) node = context->getParentNode();
while (node) {
if (nodeExpr->matches(node, context, cs))
nodes->add(node);
Node* temp = node->getPreviousSibling();
if (!temp) node = node->getParentNode();
else node = temp;
}
break;
case PRECEDING_SIBLING_AXIS:
node = context->getPreviousSibling();
while (node) {
if (nodeExpr->matches(node, context, cs))
nodes->add(node);
node = node->getPreviousSibling();
}
break;
case SELF_AXIS :
if ( nodeExpr->matches(context, context, cs) )
nodes->add(context);
break;
default: //-- Children Axis
{
NodeList* nl = context->getChildNodes();
for (int i = 0; i < nl->getLength(); i++ ) {
if ( nodeExpr->matches(nl->item(i), context, cs) )
nodes->add(nl->item(i));
}
break;
}
} //-- switch
//-- apply predicates
evaluatePredicates(nodes, cs);
return nodes;
} //-- evaluate
/**
* Returns the default priority of this Pattern based on the given Node,
* context Node, and ContextState.
* If this pattern does not match the given Node under the current context Node and
* ContextState then Negative Infinity is returned.
**/
double LocationStep::getDefaultPriority(Node* node, Node* context, ContextState* cs) {
if ( !nodeExpr ) {
return Double::NEGATIVE_INFINITY;
}
if (!PredicateList::isEmpty()) {
return 0.5;
}
return nodeExpr->getDefaultPriority(node, context, cs);
} //-- getDefaultPriority
void LocationStep::fromDescendants(Node* context, ContextState* cs, NodeSet* nodes) {
if (( !context ) || (! nodeExpr )) return;
NodeList* nl = context->getChildNodes();
for (int i = 0; i < nl->getLength(); i++) {
Node* child = nl->item(i);
if (nodeExpr->matches(child, context, cs))
nodes->add(child);
//-- check childs descendants
if (child->hasChildNodes()) fromDescendants(child, cs, nodes);
}
} //-- fromDescendants
/**
* Determines whether this PatternExpr matches the given node within
* the given context
**/
MBool LocationStep::matches(Node* node, Node* context, ContextState* cs) {
if ( !nodeExpr ) return MB_FALSE;
NodeSet* nodes = (NodeSet*) evaluate(context, cs);
MBool result = nodes->contains(node);
delete nodes;
return result;
} //-- matches
/**
* Creates a String representation of this Expr
* @param str the destination String to append to
* @see Expr
**/
void LocationStep::toString(String& str) {
switch (axisIdentifier) {
case ANCESTOR_AXIS :
str.append("ancestor::");
break;
case ANCESTOR_OR_SELF_AXIS :
str.append("ancestor-or-self::");
break;
case DESCENDANT_AXIS:
str.append("descendant::");
break;
case DESCENDANT_OR_SELF_AXIS:
str.append("descendant-or-self::");
break;
case FOLLOWING_AXIS :
str.append("following::");
break;
case FOLLOWING_SIBLING_AXIS:
str.append("following-sibling::");
break;
case NAMESPACE_AXIS:
str.append("namespace::");
break;
case PARENT_AXIS :
str.append("parent::");
break;
case PRECEDING_AXIS :
str.append("preceding::");
break;
case PRECEDING_SIBLING_AXIS :
str.append("preceding-sibling::");
break;
case SELF_AXIS :
str.append("self::");
break;
default:
break;
}
if ( nodeExpr ) nodeExpr->toString(str);
else str.append("null");
PredicateList::toString(str);
} //-- toString