org.apache.xpath
Class XPathVisitor
java.lang.Object
org.apache.xpath.XPathVisitor
public class XPathVisitor
extends java.lang.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.
boolean | visitBinaryOperation(ExpressionOwner owner, Operation op) - Visit a binary operation.
|
boolean | visitFunction(ExpressionOwner owner, Function func) - Visit a function.
|
boolean | visitLocationPath(ExpressionOwner owner, LocPathIterator path) - Visit a LocationPath.
|
boolean | visitMatchPattern(ExpressionOwner owner, StepPattern pattern) - Visit a match pattern.
|
boolean | visitNumberLiteral(ExpressionOwner owner, XNumber num) - Visit a number literal.
|
boolean | visitPredicate(ExpressionOwner owner, Expression pred) - Visit a predicate within a location path.
|
boolean | visitStep(ExpressionOwner owner, NodeTest step) - Visit a step within a location path.
|
boolean | visitStringLiteral(ExpressionOwner owner, XString str) - Visit a string literal.
|
boolean | visitUnaryOperation(ExpressionOwner owner, UnaryOperation op) - Visit a unary operation.
|
boolean | visitUnionPath(ExpressionOwner owner, UnionPathIterator path) - Visit a UnionPath.
|
boolean | visitUnionPattern(ExpressionOwner owner, UnionPattern pattern) - Visit a union pattern.
|
boolean | visitVariableRef(ExpressionOwner owner, Variable var) - Visit a variable reference.
|
visitBinaryOperation
public boolean visitBinaryOperation(ExpressionOwner owner,
Operation op)
Visit a binary operation.
owner
- The owner of the expression, to which the expression can
be reset if rewriting takes place.op
- The operation object.
- true if the sub expressions should be traversed.
visitFunction
public boolean visitFunction(ExpressionOwner owner,
Function func)
Visit a function.
owner
- The owner of the expression, to which the expression can
be reset if rewriting takes place.func
- The function reference object.
- true if the sub expressions should be traversed.
visitLocationPath
public boolean visitLocationPath(ExpressionOwner owner,
LocPathIterator path)
Visit a LocationPath.
owner
- The owner of the expression, to which the expression can
be reset if rewriting takes place.path
- The LocationPath object.
- true if the sub expressions should be traversed.
visitMatchPattern
public boolean visitMatchPattern(ExpressionOwner owner,
StepPattern pattern)
Visit a match pattern.
owner
- The owner of the expression, to which the expression can
be reset if rewriting takes place.pattern
- The match pattern object.
- true if the sub expressions should be traversed.
visitNumberLiteral
public boolean visitNumberLiteral(ExpressionOwner owner,
XNumber num)
Visit a number literal.
owner
- The owner of the expression, to which the expression can
be reset if rewriting takes place.num
- The number literal object.
- true if the sub expressions should be traversed.
visitPredicate
public boolean visitPredicate(ExpressionOwner owner,
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.
owner
- The owner of the expression, to which the expression can
be reset if rewriting takes place.pred
- The predicate object.
- true if the sub expressions should be traversed.
visitStep
public boolean visitStep(ExpressionOwner owner,
NodeTest step)
Visit a step within a location path.
owner
- The owner of the expression, to which the expression can
be reset if rewriting takes place.step
- The Step object.
- true if the sub expressions should be traversed.
visitStringLiteral
public boolean visitStringLiteral(ExpressionOwner owner,
XString str)
Visit a string literal.
owner
- The owner of the expression, to which the expression can
be reset if rewriting takes place.str
- The string literal object.
- true if the sub expressions should be traversed.
visitUnaryOperation
public boolean visitUnaryOperation(ExpressionOwner owner,
UnaryOperation op)
Visit a unary operation.
owner
- The owner of the expression, to which the expression can
be reset if rewriting takes place.op
- The operation object.
- true if the sub expressions should be traversed.
visitUnionPath
public boolean visitUnionPath(ExpressionOwner owner,
UnionPathIterator path)
Visit a UnionPath.
owner
- The owner of the expression, to which the expression can
be reset if rewriting takes place.path
- The UnionPath object.
- true if the sub expressions should be traversed.
visitUnionPattern
public boolean visitUnionPattern(ExpressionOwner owner,
UnionPattern pattern)
Visit a union pattern.
owner
- The owner of the expression, to which the expression can
be reset if rewriting takes place.pattern
- The union pattern object.
- true if the sub expressions should be traversed.
visitVariableRef
public boolean visitVariableRef(ExpressionOwner owner,
Variable var)
Visit a variable reference.
owner
- The owner of the expression, to which the expression can
be reset if rewriting takes place.var
- The variable reference object.
- true if the sub expressions should be traversed.
Copyright © 2006 Apache XML Project. All Rights Reserved.