com.novell.xml.xpath
Class BooleanValue

java.lang.Object
  com.novell.xml.xpath.BooleanValue

All Implemented Interfaces:

Expression, ExpressionValue

public class BooleanValue

extends Object

implements ExpressionValue, Expression

Class to represent a boolean expression value

Field Summary

Fields inherited from interface com.novell.xml.xpath.ExpressionValue

BOOLEAN, EXTENDED, NATIVE, NODE_SET, NUMBER, STRING

Constructor Summary

BooleanValue()
Construct a default BooleanValue for use in casting.

BooleanValue(boolean v)
Construct boolean value

Method Summary

void	castFrom(Object type) Convert from a different type of expression value to the BooleanValue type This is used primarily for converting parameters for function calls.
void	dump(PrintWriter writer) Output a human-readable form for the value
void	dump(PrintWriter writer, int indent) Print the expression in a readable form for debugging.
boolean	equals(Object other) Compare this object to another.
ExpressionValue	evaluate(Node contextNode, ExpressionContext context) Evaluate the expression with repect to the passed context
static Class	getArgType() Return the Class object for objects of this type.
boolean	getBooleanValue() Return boolean value of expression value (will convert to boolean if value is not of type boolean)
Object	getNativeValue() return the underlying native value (java.lang.Boolean, java.lang.Double, etc.)
NodeSet	getNodeSetValue() Return node-set value of this ExpressionValue.
double	getNumberValue() Return numeric value of ExpressionValue.
Class	getResultType() Return the Class object describing the result type of the expression.
String	getStringValue() Return string value of this ExpressionValue.
int	getValueType() Return type of expression value
int	hashCode() Return a hash code for this object.
boolean	isConstant() Return true if the expression is a constant value.
void	not() Convenience function that performs a logical not on the value of the BooleanValue
void	registerForReset(XPathResetRegistrar registrar) Register this expression or any subexpression that implements XPathResetCache with an object that wants to call resetCache()
String	toString() Provide a readable description for debugging.

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

BooleanValue

public BooleanValue(boolean v)

Construct boolean value

Parameters:

v -

BooleanValue

public BooleanValue()

Construct a default BooleanValue for use in casting.

Method Detail

getArgType

public static Class getArgType()

Return the Class object for objects of this type. This is used for FunctionSignature objects.

Returns:

The Class object corresponding to BooleanValue

toString

public String toString()

Provide a readable description for debugging.

Returns:

String representation

evaluate

public ExpressionValue evaluate(Node contextNode,
                                ExpressionContext context)

Evaluate the expression with repect to the passed context

Specified by:

evaluate in interface Expression

Parameters:

contextNode - context node for expression evaluation

context - expression context for expression evaluation

Returns:

result of evaluating expression

isConstant

public boolean isConstant()

Return true if the expression is a constant value.

Specified by:

isConstant in interface Expression

Returns:

True is expression is constant, false otherwise.

getResultType

public Class getResultType()

Return the Class object describing the result type of the expression.

Specified by:

getResultType in interface Expression

Returns:

A Class object.

registerForReset

public void registerForReset(XPathResetRegistrar registrar)

Register this expression or any subexpression that implements XPathResetCache with an object that wants to call resetCache()

Specified by:

registerForReset in interface Expression

dump

public void dump(PrintWriter writer,
                 int indent)

Print the expression in a readable form for debugging.

Specified by:

dump in interface Expression

Parameters:

writer - The output device.

indent - Number of tabs to indent the result.

getValueType

public int getValueType()

Return type of expression value

Specified by:

getValueType in interface ExpressionValue

Returns:

ExpressionValue.BOOLEAN, ExpressionValue.NUMBER, etc.

castFrom

public void castFrom(Object type)
              throws XPathConversionException

Convert from a different type of expression value to the BooleanValue type This is used primarily for converting parameters for function calls.

Specified by:

castFrom in interface ExpressionValue

Parameters:

type - The object to convert from.

Throws:

XPathConversionException

getBooleanValue

public boolean getBooleanValue()
                        throws XPathConversionException

Return boolean value of expression value (will convert to boolean if value is not of type boolean)

Specified by:

getBooleanValue in interface ExpressionValue

Returns:

true or false

Throws:

XPathConversionException

getNumberValue

public double getNumberValue()
                      throws XPathConversionException

Return numeric value of ExpressionValue. Will convert to a number if value is not of NUMBER type

Specified by:

getNumberValue in interface ExpressionValue

Returns:

numeric value

Throws:

XPathConversionException

getStringValue

public String getStringValue()

Return string value of this ExpressionValue. Will convert to a string if underlying type is not string.

Specified by:

getStringValue in interface ExpressionValue

Returns:

String value of ExpressionValue

getNodeSetValue

public NodeSet getNodeSetValue()
                        throws XPathConversionException

Return node-set value of this ExpressionValue. Will NOT convert an underlying type to a node-set.

Specified by:

getNodeSetValue in interface ExpressionValue

Throws:

XPathConversionException

getNativeValue

public Object getNativeValue()

return the underlying native value (java.lang.Boolean, java.lang.Double, etc.)

Specified by:

getNativeValue in interface ExpressionValue

Returns:

The native java class that is the value

dump

public void dump(PrintWriter writer)

Output a human-readable form for the value

Specified by:

dump in interface ExpressionValue

Parameters:

writer - Output device

not

public void not()

Convenience function that performs a logical not on the value of the BooleanValue

hashCode

public int hashCode()

Return a hash code for this object. Uses same algorithm as java.lang.Boolean.

Returns:

a hash code for this object.

equals

public boolean equals(Object other)

Compare this object to another. Returns true if the other Object is a BooleanValue or a java.lang.Boolean that represents the same boolean value as this object.

Parameters:

other - the Object to compare against.

Returns:

true or false