net.sourceforge.htmlunit.xpath

Class XPathVisitor

java.lang.Object

net.sourceforge.htmlunit.xpath.XPathVisitor

Direct Known Subclasses:

HasPositionalPredChecker

public class XPathVisitor
extends Object

A derivation from this class can be passed to a class that implements the XPathVisitable interface, to have the appropriate method called for each component of the XPath. Aside from possible other uses, the main intention is to provide a reasonable means to perform expression rewriting.

Each method has the form boolean visitComponentType(ExpressionOwner owner, ComponentType compType). The ExpressionOwner argument is the owner of the component, and can be used to reset the expression for rewriting. If a method returns false, the sub hierarchy will not be traversed.

This class is meant to be a base class that will be derived by concrete classes, and doesn't much except return true for each method.

Constructor Summary

Constructors

Constructor and Description
XPathVisitor()

Method Summary

Modifier and Type	Method and Description
boolean	visitBinaryOperation() Visit a binary operation.
boolean	visitFunction(Function func) Visit a function.
boolean	visitLocationPath() Visit a LocationPath.
boolean	visitMatchPattern() Visit a match pattern.
void	visitNumberLiteral() Visit a number literal.
boolean	visitPredicate(Expression pred) Visit a predicate within a location path.
boolean	visitStep() Visit a step within a location path.
void	visitStringLiteral() Visit a string literal.
boolean	visitUnaryOperation() Visit a unary operation.
boolean	visitUnionPath() Visit a UnionPath.
void	visitUnionPattern() Visit a union pattern.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

XPathVisitor

public XPathVisitor()

Method Detail

visitLocationPath

public boolean visitLocationPath()

Visit a LocationPath.

Returns:

true if the sub expressions should be traversed.

visitUnionPath

public boolean visitUnionPath()

Visit a UnionPath.

Returns:

true if the sub expressions should be traversed.

visitStep

public boolean visitStep()

Visit a step within a location path.

Returns:

true if the sub expressions should be traversed.

visitPredicate

public boolean visitPredicate(Expression pred)

Visit a predicate within a location path. Note that there isn't a proper unique component for predicates, and that the expression will be called also for whatever type Expression is.

Parameters:

pred - The predicate object.

Returns:

true if the sub expressions should be traversed.

visitBinaryOperation

public boolean visitBinaryOperation()

Visit a binary operation.

Returns:

true if the sub expressions should be traversed.

visitUnaryOperation

public boolean visitUnaryOperation()

Visit a unary operation.

Returns:

true if the sub expressions should be traversed.

visitFunction

public boolean visitFunction(Function func)

Visit a function.

Parameters:

func - The function reference object.

Returns:

true if the sub expressions should be traversed.

visitMatchPattern

public boolean visitMatchPattern()

Visit a match pattern.

Returns:

true if the sub expressions should be traversed.

visitUnionPattern

public void visitUnionPattern()

Visit a union pattern.

visitStringLiteral

public void visitStringLiteral()

Visit a string literal.

visitNumberLiteral

public void visitNumberLiteral()

Visit a number literal.