Package org.apache.xpath
Class XPathVisitor
java.lang.Object
org.apache.xpath.XPathVisitor
- Direct Known Subclasses:
AbsPathChecker
,ExpressionVisitor
,HasPositionalPredChecker
,VarNameCollector
,XSLTVisitor
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.
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Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionboolean
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.
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Constructor Details
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XPathVisitor
public XPathVisitor()
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Method Details
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visitLocationPath
Visit a LocationPath.- Parameters:
owner
- The owner of the expression, to which the expression can be reset if rewriting takes place.path
- The LocationPath object.- Returns:
- true if the sub expressions should be traversed.
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visitUnionPath
Visit a UnionPath.- Parameters:
owner
- The owner of the expression, to which the expression can be reset if rewriting takes place.path
- The UnionPath object.- Returns:
- true if the sub expressions should be traversed.
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visitStep
Visit a step within a location path.- Parameters:
owner
- The owner of the expression, to which the expression can be reset if rewriting takes place.step
- The Step object.- Returns:
- true if the sub expressions should be traversed.
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visitPredicate
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:
owner
- The owner of the expression, to which the expression can be reset if rewriting takes place.pred
- The predicate object.- Returns:
- true if the sub expressions should be traversed.
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visitBinaryOperation
Visit a binary operation.- Parameters:
owner
- The owner of the expression, to which the expression can be reset if rewriting takes place.op
- The operation object.- Returns:
- true if the sub expressions should be traversed.
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visitUnaryOperation
Visit a unary operation.- Parameters:
owner
- The owner of the expression, to which the expression can be reset if rewriting takes place.op
- The operation object.- Returns:
- true if the sub expressions should be traversed.
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visitVariableRef
Visit a variable reference.- Parameters:
owner
- The owner of the expression, to which the expression can be reset if rewriting takes place.var
- The variable reference object.- Returns:
- true if the sub expressions should be traversed.
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visitFunction
Visit a function.- Parameters:
owner
- The owner of the expression, to which the expression can be reset if rewriting takes place.func
- The function reference object.- Returns:
- true if the sub expressions should be traversed.
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visitMatchPattern
Visit a match pattern.- Parameters:
owner
- The owner of the expression, to which the expression can be reset if rewriting takes place.pattern
- The match pattern object.- Returns:
- true if the sub expressions should be traversed.
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visitUnionPattern
Visit a union pattern.- Parameters:
owner
- The owner of the expression, to which the expression can be reset if rewriting takes place.pattern
- The union pattern object.- Returns:
- true if the sub expressions should be traversed.
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visitStringLiteral
Visit a string literal.- Parameters:
owner
- The owner of the expression, to which the expression can be reset if rewriting takes place.str
- The string literal object.- Returns:
- true if the sub expressions should be traversed.
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visitNumberLiteral
Visit a number literal.- Parameters:
owner
- The owner of the expression, to which the expression can be reset if rewriting takes place.num
- The number literal object.- Returns:
- true if the sub expressions should be traversed.
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