org.jaxen.expr.PredicateSet Maven / Gradle / Ivy
/*
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*
* ====================================================================
*
* Copyright 2000-2002 bob mcwhirter & James Strachan.
* All rights reserved.
*
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
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* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
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* contributors may be used to endorse or promote products derived
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*
* ====================================================================
* This software consists of voluntary contributions made by many
* individuals on behalf of the Jaxen Project and was originally
* created by bob mcwhirter and
* James Strachan . For more information on the
* Jaxen Project, please see
* Represents the collection of predicates that follow the node-test in a
* location path.
*
*
*
* There is no rule that the same predicate may not
* appear twice in an XPath expression, nor does this class enforce any such rule.
* This is implemented more as a list than a set. However, adding the swme predicate
* twice should have no effect on the final result other than slowing it down.
*
*/
@SuppressWarnings({"rawtypes", "unchecked"})
public class PredicateSet implements Serializable
{
private static final long serialVersionUID = -7166491740228977853L;
private List predicates;
/**
* Create a new empty predicate set.
*/
public PredicateSet()
{
this.predicates = Collections.EMPTY_LIST;
}
/**
* Add a predicate to the set.
*
* @param predicate the predicate to be inserted
*/
public void addPredicate(Predicate predicate)
{
if ( this.predicates == Collections.EMPTY_LIST )
{
this.predicates = new ArrayList();
}
this.predicates.add( predicate );
}
/**
* Returns the list containing the predicates.
* This list is live, not a copy.
*
* @return a live list of predicates
*/
public List getPredicates()
{
return this.predicates;
}
/**
* Simplify each of the predicates in the list.
*/
public void simplify()
{
Iterator predIter = this.predicates.iterator();
Predicate eachPred = null;
while ( predIter.hasNext() )
{
eachPred = (Predicate) predIter.next();
eachPred.simplify();
}
}
/**
* Returns the XPath string containing each of the predicates.
*
* @return the XPath string containing each of the predicates
*/
public String getText()
{
StringBuffer buf = new StringBuffer();
Iterator predIter = this.predicates.iterator();
Predicate eachPred = null;
while ( predIter.hasNext() )
{
eachPred = (Predicate) predIter.next();
buf.append( eachPred.getText() );
}
return buf.toString();
}
/**
* Returns true if any of the supplied nodes satisfy
* all the predicates in the set. Returns false if none of the supplied
* nodes matches all the predicates in the set. Returns false if the
* node-set is empty.
*
* @param contextNodeSet the nodes to test against these predicates
* @param support ????
* @return true if any node in the contextNodeSet matches all the predicates
* @throws JaxenException
*/
protected boolean evaluateAsBoolean(List contextNodeSet,
ContextSupport support) throws JaxenException
{
return anyMatchingNode( contextNodeSet, support );
}
private boolean anyMatchingNode(List contextNodeSet, ContextSupport support)
throws JaxenException {
// Easy way out (necessary)
if (predicates.size() == 0) {
return false;
}
Iterator predIter = predicates.iterator();
// initial list to filter
List nodes2Filter = contextNodeSet;
// apply all predicates
while(predIter.hasNext()) {
final int nodes2FilterSize = nodes2Filter.size();
// Set up a dummy context with a list to hold each node
Context predContext = new Context(support);
List tempList = new ArrayList(1);
predContext.setNodeSet(tempList);
// loop through the current nodes to filter and add to the
// filtered nodes list if the predicate succeeds
for (int i = 0; i < nodes2FilterSize; ++i) {
Object contextNode = nodes2Filter.get(i);
tempList.clear();
tempList.add(contextNode);
predContext.setNodeSet(tempList);
// ????
predContext.setPosition(i + 1);
predContext.setSize(nodes2FilterSize);
Object predResult = ((Predicate)predIter.next()).evaluate(predContext);
if (predResult instanceof Number) {
// Here we assume nodes are in forward or reverse order
// as appropriate for axis
int proximity = ((Number) predResult).intValue();
if (proximity == (i + 1)) {
return true;
}
}
else {
Boolean includes =
BooleanFunction.evaluate(predResult,
predContext.getNavigator());
if (includes.booleanValue()) {
return true;
}
}
}
}
return false;
}
/**
* Returns all of the supplied nodes that satisfy
* all the predicates in the set.
*
* @param contextNodeSet the nodes to test against these predicates
* @param support ????
* @return all the nodes that match each of the predicates
* @throws JaxenException
*/
protected List evaluatePredicates(List contextNodeSet, ContextSupport support)
throws JaxenException {
// Easy way out (necessary)
if (predicates.size() == 0) {
return contextNodeSet;
}
Iterator predIter = predicates.iterator();
// initial list to filter
List nodes2Filter = contextNodeSet;
// apply all predicates
while(predIter.hasNext()) {
nodes2Filter =
applyPredicate((Predicate)predIter.next(), nodes2Filter, support);
}
return nodes2Filter;
}
public List applyPredicate(Predicate predicate, List nodes2Filter, ContextSupport support)
throws JaxenException {
final int nodes2FilterSize = nodes2Filter.size();
List filteredNodes = new ArrayList(nodes2FilterSize);
// Set up a dummy context with a list to hold each node
Context predContext = new Context(support);
List tempList = new ArrayList(1);
predContext.setNodeSet(tempList);
// loop through the current nodes to filter and add to the
// filtered nodes list if the predicate succeeds
for (int i = 0; i < nodes2FilterSize; ++i) {
Object contextNode = nodes2Filter.get(i);
tempList.clear();
tempList.add(contextNode);
predContext.setNodeSet(tempList);
// ????
predContext.setPosition(i + 1);
predContext.setSize(nodes2FilterSize);
Object predResult = predicate.evaluate(predContext);
if (predResult instanceof Number) {
// Here we assume nodes are in forward or reverse order
// as appropriate for axis
int proximity = ((Number) predResult).intValue();
if (proximity == (i + 1)) {
filteredNodes.add(contextNode);
}
}
else {
Boolean includes =
BooleanFunction.evaluate(predResult,
predContext.getNavigator());
if (includes.booleanValue()) {
filteredNodes.add(contextNode);
}
}
}
return filteredNodes;
}
}