net.sourceforge.htmlunit.xpath.objects

Class XObject

java.lang.Object

net.sourceforge.htmlunit.xpath.Expression

net.sourceforge.htmlunit.xpath.objects.XObject

All Implemented Interfaces:

SourceLocator, ExpressionNode, XPathVisitable

Direct Known Subclasses:

NodeSequence, XBoolean, XNumber, XString

public class XObject
extends Expression

This class represents an XPath object, and is capable of converting the object to various types, such as a string. This class acts as the base class to other XPath type objects, such as XString, and provides polymorphic casting capabilities.

Field Summary

Fields

Modifier and Type	Field and Description
static int	CLASS_BOOLEAN Constant for BOOLEAN object type
static int	CLASS_NODESET Constant for NODESET object type
static int	CLASS_NULL Constant for NULL object type
static int	CLASS_NUMBER Constant for NUMBER object type
static int	CLASS_RTREEFRAG Constant for RESULT TREE FRAGMENT object type
static int	CLASS_STRING Constant for STRING object type
static int	CLASS_UNKNOWN Constant for UNKNOWN object type
protected Object	m_obj The java object which this object wraps.

Constructor Summary

Constructors

Constructor and Description
XObject() Create an XObject.
XObject(Object obj) Create an XObject.

Method Summary

Modifier and Type	Method and Description
void	allowDetachToRelease(boolean allowRelease) Specify if it's OK for detach to release the iterator for reuse.
boolean	bool() Cast result object to a boolean.
boolean	boolWithSideEffects() Cast result object to a boolean, but allow side effects, such as the incrementing of an iterator.
void	callVisitors(XPathVisitor visitor) This will traverse the hierarchy, calling the visitor for each member.
boolean	deepEquals(Expression expr) Compare this object with another object and see if they are equal, include the sub heararchy.
void	detach() Detaches the DTMIterator from the set which it iterated over, releasing any computational resources and placing the iterator in the INVALID state.
boolean	equals(XObject obj2) Tell if two objects are functionally equal.
protected void	error(String msg) Tell the user of an error, and probably throw an exception.
protected void	error(String msg, Object[] args) Tell the user of an error, and probably throw an exception.
XObject	execute(XPathContext xctxt) Execute an expression in the XPath runtime context, and return the result of the expression.
int	getType() Tell what kind of class this is.
String	getTypeString() Given a request type, return the equivalent string.
boolean	greaterThan(XObject obj2) Tell if one object is greater than the other.
boolean	greaterThanOrEqual(XObject obj2) Tell if one object is greater than or equal to the other.
DTMIterator	iter() Cast result object to a nodelist.
boolean	lessThan(XObject obj2) Tell if one object is less than the other.
boolean	lessThanOrEqual(XObject obj2) Tell if one object is less than or equal to the other.
NodeSetDTM	mutableNodeset() Cast result object to a nodelist.
NodeList	nodelist() Cast result object to a nodelist.
org.w3c.dom.traversal.NodeIterator	nodeset() Cast result object to a nodelist.
boolean	notEquals(XObject obj2) Tell if two objects are functionally not equal.
double	num() Cast result object to a number.
double	numWithSideEffects() Cast result object to a number, but allow side effects, such as the incrementing of an iterator.
Object	object() Return a java object that's closest to the representation that should be handed to an extension.
protected void	setObject(Object obj)
String	str() Cast result object to a string.
String	toString()
XString	xstr() Cast result object to a string.

Methods inherited from class net.sourceforge.htmlunit.xpath.Expression

asIterator, asNode, assertion, bool, canTraverseOutsideSubtree, error, execute, execute, execute, exprGetParent, exprSetParent, getColumnNumber, getExpressionOwner, getLineNumber, getPublicId, getSystemId, isSameClass, isStableNumber, num

Methods inherited from class java.lang.Object

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

Field Detail

m_obj

protected Object m_obj

The java object which this object wraps.

CLASS_NULL

public static final int CLASS_NULL

Constant for NULL object type

See Also:

Constant Field Values

CLASS_UNKNOWN

public static final int CLASS_UNKNOWN

Constant for UNKNOWN object type

See Also:

Constant Field Values

CLASS_BOOLEAN

public static final int CLASS_BOOLEAN

Constant for BOOLEAN object type

See Also:

Constant Field Values

CLASS_NUMBER

public static final int CLASS_NUMBER

Constant for NUMBER object type

See Also:

Constant Field Values

CLASS_STRING

public static final int CLASS_STRING

Constant for STRING object type

See Also:

Constant Field Values

CLASS_NODESET

public static final int CLASS_NODESET

Constant for NODESET object type

See Also:

Constant Field Values

CLASS_RTREEFRAG

public static final int CLASS_RTREEFRAG

Constant for RESULT TREE FRAGMENT object type

See Also:

Constant Field Values

Constructor Detail

XObject

public XObject()

Create an XObject.

XObject

public XObject(Object obj)

Create an XObject.

Parameters:

obj - Can be any object, should be a specific type for derived classes, or null.

Method Detail

setObject

protected void setObject(Object obj)

execute

public XObject execute(XPathContext xctxt)
                throws TransformerException

Execute an expression in the XPath runtime context, and return the result of the expression.

Specified by:

execute in class Expression

Parameters:

xctxt - The XPath runtime context.

Returns:

The result of the expression in the form of a XObject.

Throws:

TransformerException - if a runtime exception occurs.

allowDetachToRelease

public void allowDetachToRelease(boolean allowRelease)

Specify if it's OK for detach to release the iterator for reuse. This function should be called with a value of false for objects that are stored in variables. Calling this with a value of false on a XNodeSet will cause the nodeset to be cached.

Parameters:

allowRelease - true if it is OK for detach to release this iterator for pooling.

detach

public void detach()

Detaches the DTMIterator from the set which it iterated over, releasing any computational resources and placing the iterator in the INVALID state. After detach has been invoked, calls to nextNode or previousNode will raise a runtime exception.

getType

public int getType()

Tell what kind of class this is.

Returns:

CLASS_UNKNOWN

getTypeString

public String getTypeString()

Given a request type, return the equivalent string. For diagnostic purposes.

Returns:

type string "#UNKNOWN" + object class name

num

public double num()
           throws TransformerException

Cast result object to a number. Always issues an error.

Returns:

0.0

Throws:

TransformerException - in case of error in case of error

numWithSideEffects

public double numWithSideEffects()
                          throws TransformerException

Cast result object to a number, but allow side effects, such as the incrementing of an iterator.

Returns:

numeric value of the string conversion from the next node in the NodeSetDTM, or NAN if no node was found

Throws:

TransformerException

bool

public boolean bool()
             throws TransformerException

Cast result object to a boolean. Always issues an error.

Returns:

false

Throws:

TransformerException - in case of error in case of error

boolWithSideEffects

public boolean boolWithSideEffects()
                            throws TransformerException

Cast result object to a boolean, but allow side effects, such as the incrementing of an iterator.

Returns:

True if there is a next node in the nodeset

Throws:

TransformerException

xstr

public XString xstr()

Cast result object to a string.

Returns:

The string this wraps or the empty string if null

str

public String str()

Cast result object to a string.

Returns:

The object as a string

toString

public String toString()

Overrides:

toString in class Object

object

public Object object()

Return a java object that's closest to the representation that should be handed to an extension.

Returns:

The object that this class wraps

iter

public DTMIterator iter()
                 throws TransformerException

Cast result object to a nodelist. Always issues an error.

Returns:

null

Throws:

TransformerException - in case of error in case of error

nodeset

public org.w3c.dom.traversal.NodeIterator nodeset()
                                           throws TransformerException

Cast result object to a nodelist. Always issues an error.

Returns:

null

Throws:

TransformerException - in case of error in case of error

nodelist

public NodeList nodelist()
                  throws TransformerException

Cast result object to a nodelist. Always issues an error.

Returns:

null

Throws:

TransformerException - in case of error in case of error

mutableNodeset

public NodeSetDTM mutableNodeset()
                          throws TransformerException

Cast result object to a nodelist. Always issues an error.

Returns:

The object as a NodeSetDTM.

Throws:

TransformerException - in case of error in case of error

lessThan

public boolean lessThan(XObject obj2)
                 throws TransformerException

Tell if one object is less than the other.

Parameters:

obj2 - Object to compare this to

Returns:

True if this object is less than the given object

Throws:

TransformerException - in case of error in case of error

lessThanOrEqual

public boolean lessThanOrEqual(XObject obj2)
                        throws TransformerException

Tell if one object is less than or equal to the other.

Parameters:

obj2 - Object to compare this to

Returns:

True if this object is less than or equal to the given object

Throws:

TransformerException - in case of error

greaterThan

public boolean greaterThan(XObject obj2)
                    throws TransformerException

Tell if one object is greater than the other.

Parameters:

obj2 - Object to compare this to

Returns:

True if this object is greater than the given object

Throws:

TransformerException - in case of error

greaterThanOrEqual

public boolean greaterThanOrEqual(XObject obj2)
                           throws TransformerException

Tell if one object is greater than or equal to the other.

Parameters:

obj2 - Object to compare this to

Returns:

True if this object is greater than or equal to the given object

Throws:

TransformerException - in case of error

equals

public boolean equals(XObject obj2)

Tell if two objects are functionally equal.

Parameters:

obj2 - Object to compare this to

Returns:

True if this object is equal to the given object

notEquals

public boolean notEquals(XObject obj2)
                  throws TransformerException

Tell if two objects are functionally not equal.

Parameters:

obj2 - Object to compare this to

Returns:

True if this object is not equal to the given object

Throws:

TransformerException - in case of error

error

protected void error(String msg)
              throws TransformerException

Tell the user of an error, and probably throw an exception.

Parameters:

msg - Error message to issue

Throws:

TransformerException - in case of error

error

protected void error(String msg,
                     Object[] args)
              throws TransformerException

Tell the user of an error, and probably throw an exception.

Parameters:

msg - Error message to issue

args - Arguments to use in the message

Throws:

TransformerException - in case of error

callVisitors

public void callVisitors(XPathVisitor visitor)

This will traverse the hierarchy, 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.

deepEquals

public boolean deepEquals(Expression expr)

Compare this object with another object and see if they are equal, include the sub heararchy.

Specified by:

deepEquals in class Expression

Parameters:

expr - Another expression object.

Returns:

true if this objects class and the expr object's class are the same, and the data contained within both objects are considered equal.