org.javarosa.xpath

Class XPathLazyNodeset

java.lang.Object

org.javarosa.xpath.XPathNodeset

org.javarosa.xpath.XPathLazyNodeset

public class XPathLazyNodeset
extends XPathNodeset

Represents a set of XPath nodes returned from a path or other operation which acts on multiple paths. Current encompasses two states. 1) A nodeset which references between 0 and N nodes which are known about (but, for instance, don't match any predicates or are irrelevant). Some operations cannot be evaluated in this state directly. If more than one node is referenced, it is impossible to return a normal evaluation, for instance. 2) A nodeset which wasn't able to reference into any known model (generally a reference which is written in error). In this state, the size of the nodeset can be evaluated, but the acual reference cannot be returned, since it doesn't have any semantic value. (2) may be a deviation from normal XPath. This should be evaluated in the future.

Author:

ctsims

Field Summary

Fields inherited from class org.javarosa.xpath.XPathNodeset

ec, instance

Constructor Summary

Constructors

Constructor and Description
XPathLazyNodeset(TreeReference unExpandedRef, DataInstance instance, EvaluationContext ec) Construct an XPath nodeset.

Method Summary

Modifier and Type	Method and Description
TreeReference	getRefAt(int i)
List<TreeReference>	getReferences()
Object	getValAt(int i)
protected String	nodeContents()
int	size()
Object[]	toArgList()
Object	unpack()

Methods inherited from class org.javarosa.xpath.XPathNodeset

ConstructInvalidPathNodeset, getInvalidNodesetException, getNonEmptySize, setReferences, shuffle, shuffle

Methods inherited from class java.lang.Object

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

Constructor Detail

XPathLazyNodeset

public XPathLazyNodeset(TreeReference unExpandedRef,
                        DataInstance instance,
                        EvaluationContext ec)

Construct an XPath nodeset.

Parameters:

nodes -

instance -

ec -

Method Detail

unpack

public Object unpack()

Overrides:

unpack in class XPathNodeset

Returns:

The value represented by this xpath. Can only be evaluated when this xpath represents exactly one reference, or when it represents 0 references after a filtering operation (a reference which _could_ have existed, but didn't, rather than a reference which could not represent a real node).

toArgList

public Object[] toArgList()

Overrides:

toArgList in class XPathNodeset

getReferences

public List<TreeReference> getReferences()

Overrides:

getReferences in class XPathNodeset

size

public int size()

Overrides:

size in class XPathNodeset

getRefAt

public TreeReference getRefAt(int i)

Overrides:

getRefAt in class XPathNodeset

getValAt

public Object getValAt(int i)

Overrides:

getValAt in class XPathNodeset

nodeContents

protected String nodeContents()

Overrides:

nodeContents in class XPathNodeset