com.xmlmind.xml.xpath

Class NodeSetVariant

java.lang.Object

com.xmlmind.xml.xpath.VariantBase

com.xmlmind.xml.xpath.NodeSetVariant

All Implemented Interfaces:

Variant

public class NodeSetVariant
extends VariantBase

A Variant which is a node set (i.e. a NodeIterator) value.

A NodeSetVariant is an ephemeral object: it cannot be stored for later use, it must be immediately converted and used. And this conversion may occur only once.

Unlike the NodeSetVariant, a PermanentNodeSetVariant is not an ephemeral object: it can be stored for later use (as long as the document is not modified) and it can be converted several times.

Constructor Summary

Constructors

Constructor and Description
NodeSetVariant(NodeIterator iter) Constructs a Variant for specified node set.

Method Summary

Modifier and Type	Method and Description
boolean	convertToBoolean() Returns this Variant converted to a boolean.
NodeIterator	convertToNodeSet() Returns this Variant converted to a node set.
double	convertToNumber() Returns this Variant converted to a double.
Object	convertToObject() Returns this Variant converted to an alien Java object (typically returned by an extension function invoked using Java introspection).
String	convertToString() Returns this Variant converted to a string.
boolean	isNodeSet() Returns true if this Variant is a node set value.
Variant	makePermanent() Used to convert a node set Variant to a permanent node set Variant.
String	toString() Returns a debug string which is not useful because this method cannot be properly implemented without modifying the state of this object.

Methods inherited from class com.xmlmind.xml.xpath.VariantBase

convertToPredicate, create, isBoolean, isNumber, isString

Methods inherited from class java.lang.Object

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

Constructor Detail

NodeSetVariant

public NodeSetVariant(NodeIterator iter)

Constructs a Variant for specified node set.

Method Detail

convertToNodeSet

public NodeIterator convertToNodeSet()

Description copied from interface: Variant

Returns this Variant converted to a node set.

Specified by:

convertToNodeSet in interface Variant

Overrides:

convertToNodeSet in class VariantBase

convertToObject

public Object convertToObject()

Description copied from interface: Variant

Returns this Variant converted to an alien Java object (typically returned by an extension function invoked using Java introspection).

convertToString

public String convertToString()
                       throws EvalException

Description copied from interface: Variant

Returns this Variant converted to a string.

Throws:

EvalException - if this Variant cannot be converted to a string.

convertToBoolean

public boolean convertToBoolean()
                         throws EvalException

Description copied from interface: Variant

Returns this Variant converted to a boolean.

Throws:

EvalException - if this Variant cannot be converted to a boolean.

convertToNumber

public double convertToNumber()
                       throws EvalException

Description copied from interface: Variant

Returns this Variant converted to a double.

Specified by:

convertToNumber in interface Variant

Overrides:

convertToNumber in class VariantBase

Throws:

EvalException - if this Variant cannot be converted to a double.

makePermanent

public Variant makePermanent()
                      throws EvalException

Description copied from interface: Variant

Used to convert a node set Variant to a permanent node set Variant. No effect on other types of Variants.

Specified by:

makePermanent in interface Variant

Overrides:

makePermanent in class VariantBase

Returns:

if this Variant is a node set, returns an equivalent permanent node set; otherwise return this Variant

Throws:

EvalException - if the equivalent permanent node set cannot be created (remember that node set are almost always lazily evaluated)

See Also:

NodeSetVariant, PermanentNodeSetVariant

isNodeSet

public boolean isNodeSet()

Description copied from interface: Variant

Returns true if this Variant is a node set value.

Specified by:

isNodeSet in interface Variant

Overrides:

isNodeSet in class VariantBase

toString

public String toString()

Returns a debug string which is not useful because this method cannot be properly implemented without modifying the state of this object. Of course, a PermanentNodeSetVariant has not this problem.

Specified by:

toString in interface Variant

Overrides:

toString in class Object