net.sf.saxon.s9api
Class XdmItem

java.lang.Object
  net.sf.saxon.s9api.XdmValue
      net.sf.saxon.s9api.XdmItem

All Implemented Interfaces:

Iterable<XdmItem>

Direct Known Subclasses:

XdmAtomicValue, XdmFunctionItem, XdmNode

public abstract class XdmItem
extends XdmValue

The class XdmItem represents an item in a sequence, as defined by the XDM data model. An item is either an atomic value or a node.

An item is a member of a sequence, but it can also be considered as a sequence (of length one) in its own right. XdmItem is a subtype of XdmValue because every Item in the XDM data model is also a value.

It cannot be assumed that every sequence of length one will be represented by an XdmItem. It is quite possible for an XdmValue that is not an XdmItem to hold a singleton sequence.

Saxon provides two concrete subclasses of XdmItem, namely XdmNode and XdmAtomicValue. Users must not attempt to create additional subclasses.

Constructor Summary

protected	XdmItem()
protected	XdmItem(Item item) Construct an XdmItem as a wrapper around an existing NodeInfo object

Method Summary

String	getStringValue() Get the string value of the item.
boolean	isAtomicValue() Determine whether the item is an atomic value or a node
static XdmItem	newAtomicValue(String value, ItemType type) Deprecated. since 9.1. This factory method duplicates the constructor XdmAtomicValue.XdmAtomicValue(String, ItemType) which should be used in preference
int	size() Get the number of items in the sequence
protected static XdmItem	wrapItem(Item item)

Methods inherited from class net.sf.saxon.s9api.XdmValue

append, getUnderlyingValue, itemAt, iterator, setValue, wrap

Methods inherited from class java.lang.Object

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

Constructor Detail

XdmItem

protected XdmItem()

XdmItem

protected XdmItem(Item item)

Construct an XdmItem as a wrapper around an existing NodeInfo object

Parameters:

item - the NodeInfo object to be wrapped. This can be retrieved using the XdmValue.getUnderlyingValue() method.

Throws:

NullPointerException - if item is null

Since:

9.2 (previously a protected constructor)

Method Detail

wrapItem

protected static XdmItem wrapItem(Item item)

newAtomicValue

public static XdmItem newAtomicValue(String value,
                                     ItemType type)
                              throws SaxonApiException

Deprecated. since 9.1. This factory method duplicates the constructor XdmAtomicValue.XdmAtomicValue(String, ItemType) which should be used in preference

Factory method to construct an atomic value given its lexical representation and the required item type

Parameters:

value - the lexical representation of the required value

type - the item type of the required value

Returns:

the constructed item

Throws:

SaxonApiException - if the supplied string is not in the lexical space of the target type, or if the target type is not atomic

getStringValue

public String getStringValue()

Get the string value of the item. For a node, this gets the string value of the node. For an atomic value, it has the same effect as casting the value to a string. In all cases the result is the same as applying the XPath string() function.

For atomic values, the result is the same as the result of calling toString. This is not the case for nodes, where toString returns an XML serialization of the node.

Returns:

the result of converting the item to a string.

isAtomicValue

public boolean isAtomicValue()

Determine whether the item is an atomic value or a node

Returns:

true if the item is an atomic value, false if it is a node

size

public int size()

Get the number of items in the sequence

Overrides:

size in class XdmValue

Returns:

the number of items in the value - always one