Package org.htmlunit.xpath
Class XPath
- java.lang.Object
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- org.htmlunit.xpath.XPath
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public class XPath extends java.lang.Object
The XPath class wraps an expression object and provides general services for execution of that expression.
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Field Summary
Fields Modifier and Type Field Description private FunctionTable
m_funcTable
The function table for xpath build-in functionsprivate Expression
m_mainExp
The top of the expression tree.static int
MATCH
Represents a match type expression.static double
MATCH_SCORE_NODETEST
The match score if the pattern consists of just a NodeTest.static double
MATCH_SCORE_NONE
The match score if no match is made.static double
MATCH_SCORE_NSWILD
The match score if the pattern pattern has the form NCName:*.static double
MATCH_SCORE_OTHER
The match score if the pattern consists of something other than just a NodeTest or just a qname.static double
MATCH_SCORE_QNAME
The match score if the pattern has the form of a QName optionally preceded by an @ character.static int
SELECT
Represents a select type expression.
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Constructor Summary
Constructors Constructor Description XPath(java.lang.String exprString, PrefixResolver prefixResolver, int type)
Construct an XPath object.XPath(java.lang.String exprString, PrefixResolver prefixResolver, int type, javax.xml.transform.ErrorListener errorListener)
Construct an XPath object.XPath(java.lang.String exprString, PrefixResolver prefixResolver, int type, javax.xml.transform.ErrorListener errorListener, FunctionTable aTable)
Construct an XPath object.XPath(Expression expr)
Construct an XPath object.
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description void
callVisitors(XPathVisitor visitor)
This will traverse the heararchy, calling the visitor for each member.void
error(XPathContext xctxt, java.lang.String msg, java.lang.Object[] args)
Tell the user of an error, and probably throw an exception.XObject
execute(XPathContext xctxt, int contextNode, PrefixResolver namespaceContext)
Given an expression and a context, evaluate the XPath and return the result.XObject
execute(XPathContext xctxt, org.w3c.dom.Node contextNode, PrefixResolver namespaceContext)
Given an expression and a context, evaluate the XPath and return the result.javax.xml.transform.SourceLocator
getLocator()
Get the SourceLocator on the expression object.private void
initFunctionTable()
initial the function table
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Field Detail
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m_mainExp
private final Expression m_mainExp
The top of the expression tree.
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m_funcTable
private transient FunctionTable m_funcTable
The function table for xpath build-in functions
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SELECT
public static final int SELECT
Represents a select type expression.- See Also:
- Constant Field Values
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MATCH
public static final int MATCH
Represents a match type expression.- See Also:
- Constant Field Values
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MATCH_SCORE_NONE
public static final double MATCH_SCORE_NONE
The match score if no match is made.- See Also:
- Constant Field Values
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MATCH_SCORE_QNAME
public static final double MATCH_SCORE_QNAME
The match score if the pattern has the form of a QName optionally preceded by an @ character.- See Also:
- Constant Field Values
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MATCH_SCORE_NSWILD
public static final double MATCH_SCORE_NSWILD
The match score if the pattern pattern has the form NCName:*.- See Also:
- Constant Field Values
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MATCH_SCORE_NODETEST
public static final double MATCH_SCORE_NODETEST
The match score if the pattern consists of just a NodeTest.- See Also:
- Constant Field Values
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MATCH_SCORE_OTHER
public static final double MATCH_SCORE_OTHER
The match score if the pattern consists of something other than just a NodeTest or just a qname.- See Also:
- Constant Field Values
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Constructor Detail
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XPath
public XPath(java.lang.String exprString, PrefixResolver prefixResolver, int type, javax.xml.transform.ErrorListener errorListener) throws javax.xml.transform.TransformerException
Construct an XPath object.(Needs review -sc) This method initializes an XPathParser/ Compiler and compiles the expression.
- Parameters:
exprString
- The XPath expression.prefixResolver
- A prefix resolver to use to resolve prefixes to namespace URIs.type
- one ofSELECT
orMATCH
.errorListener
- The error listener, or null if default should be used.- Throws:
javax.xml.transform.TransformerException
- if syntax or other error.
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XPath
public XPath(java.lang.String exprString, PrefixResolver prefixResolver, int type, javax.xml.transform.ErrorListener errorListener, FunctionTable aTable) throws javax.xml.transform.TransformerException
Construct an XPath object.(Needs review -sc) This method initializes an XPathParser/ Compiler and compiles the expression.
- Parameters:
exprString
- The XPath expression.prefixResolver
- A prefix resolver to use to resolve prefixes to namespace URIs.type
- one ofSELECT
orMATCH
.errorListener
- The error listener, or null if default should be used.aTable
- the function table to be used- Throws:
javax.xml.transform.TransformerException
- if syntax or other error.
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XPath
public XPath(java.lang.String exprString, PrefixResolver prefixResolver, int type) throws javax.xml.transform.TransformerException
Construct an XPath object.(Needs review -sc) This method initializes an XPathParser/ Compiler and compiles the expression.
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XPath
public XPath(Expression expr)
Construct an XPath object.- Parameters:
expr
- The Expression object.
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Method Detail
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initFunctionTable
private void initFunctionTable()
initial the function table
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getLocator
public javax.xml.transform.SourceLocator getLocator()
Get the SourceLocator on the expression object.- Returns:
- the SourceLocator on the expression object, which may be null.
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execute
public XObject execute(XPathContext xctxt, org.w3c.dom.Node contextNode, PrefixResolver namespaceContext) throws javax.xml.transform.TransformerException
Given an expression and a context, evaluate the XPath and return the result.- Parameters:
xctxt
- The execution context.contextNode
- The node that "." expresses.namespaceContext
- The context in which namespaces in the XPath are supposed to be expanded.- Returns:
- The result of the XPath or null if callbacks are used.
- Throws:
javax.xml.transform.TransformerException
- thrown if the error condition is severe enough to halt processing.javax.xml.transform.TransformerException
- in case of error
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execute
public XObject execute(XPathContext xctxt, int contextNode, PrefixResolver namespaceContext) throws javax.xml.transform.TransformerException
Given an expression and a context, evaluate the XPath and return the result.- Parameters:
xctxt
- The execution context.contextNode
- The node that "." expresses.namespaceContext
- The context in which namespaces in the XPath are supposed to be expanded.- Throws:
javax.xml.transform.TransformerException
- thrown if the active ProblemListener decides the error condition is severe enough to halt processing.javax.xml.transform.TransformerException
- in case of error
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error
public void error(XPathContext xctxt, java.lang.String msg, java.lang.Object[] args) throws javax.xml.transform.TransformerException
Tell the user of an error, and probably throw an exception.- Parameters:
xctxt
- The XPath runtime context.msg
- An error msgkey that corresponds to one of the constants found inXPATHErrorResources
, which is a key for a format string.args
- An array of arguments represented in the format string, which may be null.- Throws:
javax.xml.transform.TransformerException
- if the current ErrorListoner determines to throw an exception.
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callVisitors
public void callVisitors(XPathVisitor visitor)
This will traverse the heararchy, calling the visitor for each member. If the called visitor method returns false, the subtree should not be called.- Parameters:
visitor
- The visitor whose appropriate method will be called.
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