org.apache.xpath.functions
Class FunctionDef1Arg

java.lang.Object
  org.apache.xpath.Expression
      org.apache.xpath.functions.Function
          org.apache.xpath.functions.FunctionOneArg
              org.apache.xpath.functions.FunctionDef1Arg

All Implemented Interfaces:

ExpressionNode, ExpressionOwner, Serializable, javax.xml.transform.SourceLocator, XPathVisitable

Direct Known Subclasses:

FuncDoclocation, FuncGenerateId, FuncLocalPart, FuncNamespace, FuncNormalizeSpace, FuncNumber, FuncQname, FuncString, FuncStringLength

public class FunctionDef1Arg

extends FunctionOneArg

Base class for functions that accept one argument that can be defaulted if not specified.

See Also:

Serialized Form

Field Summary

Fields inherited from class org.apache.xpath.functions.FunctionOneArg

m_arg0

Fields inherited from class org.apache.xpath.Expression

Constructor Summary

FunctionDef1Arg()

Method Summary

boolean	Arg0IsNodesetExpr() Tell if the expression is a nodeset expression.
boolean	canTraverseOutsideSubtree() Tell if this expression or it's subexpressions can traverse outside the current subtree.
void	checkNumberArgs(int argNum) Check that the number of arguments passed to this function is correct.
protected int	getArg0AsNode(XPathContext xctxt) Execute the first argument expression that is expected to return a nodeset.
protected double	getArg0AsNumber(XPathContext xctxt) Execute the first argument expression that is expected to return a number.
protected XMLString	getArg0AsString(XPathContext xctxt) Execute the first argument expression that is expected to return a string.
protected void	reportWrongNumberArgs() Constructs and throws a WrongNumberArgException with the appropriate message for this function object.

Methods inherited from class org.apache.xpath.functions.FunctionOneArg

callArgVisitors, deepEquals, fixupVariables, getArg0, getExpression, setArg, setExpression

Methods inherited from class org.apache.xpath.functions.Function

callVisitors, execute, postCompileStep

Methods inherited from class org.apache.xpath.Expression

asIterator, asIteratorRaw, asNode, assertion, bool, error, execute, execute, execute, executeCharsToContentHandler, exprAddChild, exprGetChild, exprGetNumChildren, exprGetParent, exprSetParent, getColumnNumber, getExpressionOwner, getLineNumber, getPublicId, getSystemId, isNodesetExpr, isSameClass, isStableNumber, num, warn, xstr

Methods inherited from class java.lang.Object

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

Constructor Detail

FunctionDef1Arg

public FunctionDef1Arg()

Method Detail

getArg0AsNode

protected int getArg0AsNode(XPathContext xctxt)
                     throws javax.xml.transform.TransformerException

Execute the first argument expression that is expected to return a nodeset. If the argument is null, then return the current context node.

Parameters:

xctxt - Runtime XPath context.

Returns:

The first node of the executed nodeset, or the current context node if the first argument is null.

Throws:

javax.xml.transform.TransformerException - if an error occurs while executing the argument expression.

Arg0IsNodesetExpr

public boolean Arg0IsNodesetExpr()

Tell if the expression is a nodeset expression.

Returns:

true if the expression can be represented as a nodeset.

getArg0AsString

protected XMLString getArg0AsString(XPathContext xctxt)
                             throws javax.xml.transform.TransformerException

Execute the first argument expression that is expected to return a string. If the argument is null, then get the string value from the current context node.

Parameters:

xctxt - Runtime XPath context.

Returns:

The string value of the first argument, or the string value of the current context node if the first argument is null.

Throws:

javax.xml.transform.TransformerException - if an error occurs while executing the argument expression.

getArg0AsNumber

protected double getArg0AsNumber(XPathContext xctxt)
                          throws javax.xml.transform.TransformerException

Execute the first argument expression that is expected to return a number. If the argument is null, then get the number value from the current context node.

Parameters:

xctxt - Runtime XPath context.

Returns:

The number value of the first argument, or the number value of the current context node if the first argument is null.

Throws:

javax.xml.transform.TransformerException - if an error occurs while executing the argument expression.

checkNumberArgs

public void checkNumberArgs(int argNum)
                     throws WrongNumberArgsException

Check that the number of arguments passed to this function is correct.

Overrides:

checkNumberArgs in class FunctionOneArg

Parameters:

argNum - The number of arguments that is being passed to the function.

Throws:

WrongNumberArgsException - if the number of arguments is not 0 or 1.

reportWrongNumberArgs

protected void reportWrongNumberArgs()
                              throws WrongNumberArgsException

Constructs and throws a WrongNumberArgException with the appropriate message for this function object.

Overrides:

reportWrongNumberArgs in class FunctionOneArg

Throws:

WrongNumberArgsException

canTraverseOutsideSubtree

public boolean canTraverseOutsideSubtree()

Tell if this expression or it's subexpressions can traverse outside the current subtree.

Overrides:

canTraverseOutsideSubtree in class FunctionOneArg

Returns:

true if traversal outside the context node's subtree can occur.